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2013-07-03lcd: add devm_lcd_device_{register,unregister}()Jingoo Han1-0/+5
These functions allow the driver core to automatically clean up any allocation made by lcd drivers. Thus it simplifies the error paths. Signed-off-by: Jingoo Han <jg1.han@samsung.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03backlight: add devm_backlight_device_{register,unregister}()Jingoo Han1-0/+6
These functions allow the driver core to automatically clean up any allocation made by backlight drivers. Thus it simplifies the error paths. Signed-off-by: Jingoo Han <jg1.han@samsung.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03drivers/dma: remove unused support for MEMSET operationsBartlomiej Zolnierkiewicz2-9/+0
There have never been any real users of MEMSET operations since they have been introduced in January 2007 by commit 7405f74badf4 ("dmaengine: refactor dmaengine around dma_async_tx_descriptor"). Therefore remove support for them for now, it can be always brought back when needed. [sebastian.hesselbarth@gmail.com: fix drivers/dma/mv_xor] Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> Cc: Vinod Koul <vinod.koul@intel.com> Acked-by: Dan Williams <djbw@fb.com> Cc: Tomasz Figa <t.figa@samsung.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Olof Johansson <olof@lixom.net> Cc: Kevin Hilman <khilman@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03dmi: add support for exact DMI matches in addition to substring matchingJani Nikula1-2/+4
dmi_match() considers a substring match to be a successful match. This is not always sufficient to distinguish between DMI data for different systems. Add support for exact string matching using strcmp() in addition to the substring matching using strstr(). The specific use case in the i915 driver is to allow us to use an exact match for D510MO, without also incorrectly matching D510MOV: { .ident = "Intel D510MO", .matches = { DMI_MATCH(DMI_BOARD_VENDOR, "Intel"), DMI_EXACT_MATCH(DMI_BOARD_NAME, "D510MO"), }, } Signed-off-by: Jani Nikula <jani.nikula@intel.com> Cc: <annndddrr@gmail.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Cornel Panceac <cpanceac@gmail.com> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03drivers: avoid format strings in names passed to alloc_workqueue()Kees Cook1-3/+4
For the workqueue creation interfaces that do not expect format strings, make sure they cannot accidently be parsed that way. Additionally, clean up calls made with a single parameter that would be handled as a format string. Many callers are passing potentially dynamic string content, so use "%s" in those cases to avoid any potential accidents. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03err.h: IS_ERR() can accept __user pointersDan Carpenter1-5/+5
Sparse generates a false positive when you pass a __user or __iomem pointer to the IS_ERR() functions. drivers/rtc/rtc-ds1286.c:344:36: sparse: incorrect type in argument 1 (different address spaces) drivers/rtc/rtc-ds1286.c:344:36: expected void const *ptr drivers/rtc/rtc-ds1286.c:344:36: got unsigned int [noderef] [usertype] <asn:2>*rtcregs We can silence these by adding a __force here and upgrading to Sparse v0.4.5-rc1 or later. This change has no effect when using current Sparse releases. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Christopher Li <sparse@chrisli.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03sparsemem: add BUILD_BUG_ON when sizeof mem_section is non-power-of-2Cody P Schafer1-0/+4
Instead of leaving a hidden trap for the next person who comes along and wants to add something to mem_section, add a big fat warning about it needing to be a power-of-2, and insert a BUILD_BUG_ON() in sparse_init() to catch mistakes. Right now non-power-of-2 mem_sections cause a number of WARNs at boot (which don't clearly point to the size of mem_section as an issue), but the system limps on (temporarily, at least). This is based upon Dave Hansen's earlier RFC where he ran into the same issue: "sparsemem: fix boot when SECTIONS_PER_ROOT is not power-of-2" http://lkml.indiana.edu/hypermail/linux/kernel/1205.2/03077.html Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Jiang Liu <liuj97@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03mm: kill free_all_bootmem_node()Jiang Liu1-1/+0
Now nobody makes use of free_all_bootmem_node(), kill it. Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Yinghai Lu <yinghai@kernel.org> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03mm: introduce helper function set_max_mapnr()Jiang Liu1-1/+8
Introduce a helper function set_max_mapnr() to set global variable max_mapnr. Also unify condition compilation for max_mapnr with CONFIG_NEED_MULTIPLE_NODES instead of CONFIG_DISCONTIGMEM. Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mauro Carvalho Chehab <mchehab@redhat.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03mm: kill global variable num_physpagesJiang Liu1-1/+0
Now all references to num_physpages have been removed, so kill it. Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Michel Lespinasse <walken@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Hugh Dickins <hughd@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03mm: introduce helper function mem_init_print_info() to simplify mem_init()Jiang Liu1-0/+12
Introduce helper function mem_init_print_info() to simplify mem_init() across different architectures, which also unifies the format and information printed. Function mem_init_print_info() calculates memory statistics information without walking each page, so it should be a little faster on some architectures. Also introduce another helper get_num_physpages() to kill the global variable num_physpages. Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Michel Lespinasse <walken@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03vmlinux.lds: add comments for global variables and clean up useless declarationsJiang Liu1-1/+20
The original goal of this patchset is to fix the bug reported by https://bugzilla.kernel.org/show_bug.cgi?id=53501 Now it has also been expanded to reduce common code used by memory initializion. Patch 1-7: 1) add comments for global variables exported by vmlinux.lds 2) normalize global variables exported by vmlinux.lds Patch 8: Introduce helper functions mem_init_print_info() and get_num_physpages() Patch 9: Avoid using global variable num_physpages at runtime Patch 10: Don't update num_physpages in memory_hotplug.c Patch 11-40: Modify arch mm initialization code to: 1) Simplify mem_init() by using mem_init_print_info() 2) Prepare for killing global variable num_physpages Patch 41: Kill the global variable num_physpages With all patches applied, mem_init(), free_initmem(), free_initrd_mem() could be as simple as below. This patch series has reduced about 1.2K lines of code in total. #ifndef CONFIG_DISCONTIGMEM void __init mem_init(void) { max_mapnr = max_low_pfn; free_all_bootmem(); high_memory = (void *) __va(max_low_pfn * PAGE_SIZE); mem_init_print_info(NULL); } #endif /* CONFIG_DISCONTIGMEM */ void free_initmem(void) { free_initmem_default(-1); } #ifdef CONFIG_BLK_DEV_INITRD void free_initrd_mem(unsigned long start, unsigned long end) { free_reserved_area(start, end, -1, "initrd"); } #endif Due to hardware resource limitations, I have only tested this on x86_64. And the messages reported on an x86_64 system are: Log message before applying patches: Memory: 7745676k/8910848k available (6934k kernel code, 836024k absent, 329148k reserved, 6343k data, 1012k init) Log message after applying patches: Memory: 7744624K/8074824K available (6969K kernel code, 1011K data, 2828K rodata, 1016K init, 9640K bss, 330200K reserved) Great thanks to Vineet Gupta for testing on ARC. This patch: Document global variables exported from vmlinux.lds. 1) Add comments about usage guidelines for global variables exported from vmlinux.lds.S. 2) Remove unused __initdata_begin[] and __initdata_end[]. Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03mm: use a dedicated lock to protect totalram_pages and zone->managed_pagesJiang Liu2-8/+12
Currently lock_memory_hotplug()/unlock_memory_hotplug() are used to protect totalram_pages and zone->managed_pages. Other than the memory hotplug driver, totalram_pages and zone->managed_pages may also be modified at runtime by other drivers, such as Xen balloon, virtio_balloon etc. For those cases, memory hotplug lock is a little too heavy, so introduce a dedicated lock to protect totalram_pages and zone->managed_pages. Now we have a simplified locking rules totalram_pages and zone->managed_pages as: 1) no locking for read accesses because they are unsigned long. 2) no locking for write accesses at boot time in single-threaded context. 3) serialize write accesses at runtime by acquiring the dedicated managed_page_count_lock. Also adjust zone->managed_pages when freeing reserved pages into the buddy system, to keep totalram_pages and zone->managed_pages in consistence. [akpm@linux-foundation.org: don't export adjust_managed_page_count to modules (for now)] Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Michel Lespinasse <walken@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: <sworddragon2@aol.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: David Howells <dhowells@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03mm: accurately calculate zone->managed_pages for highmem zonesJiang Liu1-0/+1
Commit "mm: introduce new field 'managed_pages' to struct zone" assumes that all highmem pages will be freed into the buddy system by function mem_init(). But that's not always true, some architectures may reserve some highmem pages during boot. For example PPC may allocate highmem pages for giagant HugeTLB pages, and several architectures have code to check PageReserved flag to exclude highmem pages allocated during boot when freeing highmem pages into the buddy system. So treat highmem pages in the same way as normal pages, that is to: 1) reset zone->managed_pages to zero in mem_init(). 2) recalculate managed_pages when freeing pages into the buddy system. Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Tejun Heo <tj@kernel.org> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Minchan Kim <minchan@kernel.org> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: <sworddragon2@aol.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: David Howells <dhowells@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Michel Lespinasse <walken@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03mm: enhance free_reserved_area() to support poisoning memory with zeroJiang Liu1-3/+4
Address more review comments from last round of code review. 1) Enhance free_reserved_area() to support poisoning freed memory with pattern '0'. This could be used to get rid of poison_init_mem() on ARM64. 2) A previous patch has disabled memory poison for initmem on s390 by mistake, so restore to the original behavior. 3) Remove redundant PAGE_ALIGN() when calling free_reserved_area(). Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: <sworddragon2@aol.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: David Howells <dhowells@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Michel Lespinasse <walken@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03mm: change signature of free_reserved_area() to fix building warningsJiang Liu1-3/+2
Change signature of free_reserved_area() according to Russell King's suggestion to fix following build warnings: arch/arm/mm/init.c: In function 'mem_init': arch/arm/mm/init.c:603:2: warning: passing argument 1 of 'free_reserved_area' makes integer from pointer without a cast [enabled by default] free_reserved_area(__va(PHYS_PFN_OFFSET), swapper_pg_dir, 0, NULL); ^ In file included from include/linux/mman.h:4:0, from arch/arm/mm/init.c:15: include/linux/mm.h:1301:22: note: expected 'long unsigned int' but argument is of type 'void *' extern unsigned long free_reserved_area(unsigned long start, unsigned long end, mm/page_alloc.c: In function 'free_reserved_area': >> mm/page_alloc.c:5134:3: warning: passing argument 1 of 'virt_to_phys' makes pointer from integer without a cast [enabled by default] In file included from arch/mips/include/asm/page.h:49:0, from include/linux/mmzone.h:20, from include/linux/gfp.h:4, from include/linux/mm.h:8, from mm/page_alloc.c:18: arch/mips/include/asm/io.h:119:29: note: expected 'const volatile void *' but argument is of type 'long unsigned int' mm/page_alloc.c: In function 'free_area_init_nodes': mm/page_alloc.c:5030:34: warning: array subscript is below array bounds [-Warray-bounds] Also address some minor code review comments. Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Reported-by: Arnd Bergmann <arnd@arndb.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: <sworddragon2@aol.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: David Howells <dhowells@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Michel Lespinasse <walken@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03swap: discard while swapping only if SWAP_FLAG_DISCARD_PAGESRafael Aquini1-4/+9
Considering the use cases where the swap device supports discard: a) and can do it quickly; b) but it's slow to do in small granularities (or concurrent with other I/O); c) but the implementation is so horrendous that you don't even want to send one down; And assuming that the sysadmin considers it useful to send the discards down at all, we would (probably) want the following solutions: i. do the fine-grained discards for freed swap pages, if device is capable of doing so optimally; ii. do single-time (batched) swap area discards, either at swapon or via something like fstrim (not implemented yet); iii. allow doing both single-time and fine-grained discards; or iv. turn it off completely (default behavior) As implemented today, one can only enable/disable discards for swap, but one cannot select, for instance, solution (ii) on a swap device like (b) even though the single-time discard is regarded to be interesting, or necessary to the workload because it would imply (1), and the device is not capable of performing it optimally. This patch addresses the scenario depicted above by introducing a way to ensure the (probably) wanted solutions (i, ii, iii and iv) can be flexibly flagged through swapon(8) to allow a sysadmin to select the best suitable swap discard policy accordingly to system constraints. This patch introduces SWAP_FLAG_DISCARD_PAGES and SWAP_FLAG_DISCARD_ONCE new flags to allow more flexibe swap discard policies being flagged through swapon(8). The default behavior is to keep both single-time, or batched, area discards (SWAP_FLAG_DISCARD_ONCE) and fine-grained discards for page-clusters (SWAP_FLAG_DISCARD_PAGES) enabled, in order to keep consistentcy with older kernel behavior, as well as maintain compatibility with older swapon(8). However, through the new introduced flags the best suitable discard policy can be selected accordingly to any given swap device constraint. [akpm@linux-foundation.org: tweak comments] Signed-off-by: Rafael Aquini <aquini@redhat.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: Shaohua Li <shli@kernel.org> Cc: Karel Zak <kzak@redhat.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03mm: tune vm_committed_as percpu_counter batching sizeTim Chen1-1/+7
Currently the per cpu counter's batch size for memory accounting is configured as twice the number of cpus in the system. However, for system with very large memory, it is more appropriate to make it proportional to the memory size per cpu in the system. For example, for a x86_64 system with 64 cpus and 128 GB of memory, the batch size is only 2*64 pages (0.5 MB). So any memory accounting changes of more than 0.5MB will overflow the per cpu counter into the global counter. Instead, for the new scheme, the batch size is configured to be 0.4% of the memory/cpu = 8MB (128 GB/64 /256), which is more inline with the memory size. I've done a repeated brk test of 800KB (from will-it-scale test suite) with 80 concurrent processes on a 4 socket Westmere machine with a total of 40 cores. Without the patch, about 80% of cpu is spent on spin-lock contention within the vm_committed_as counter. With the patch, there's a 73x speedup on the benchmark and the lock contention drops off almost entirely. [akpm@linux-foundation.org: fix section mismatch] Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Cc: Tejun Heo <tj@kernel.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03mm/hugetlb: remove hugetlb_prefaultWanpeng Li1-2/+0
hugetlb_prefault() is not used any more, this patch removes it. Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03mm/pageblock: remove get/set_pageblock_flagsWanpeng Li1-6/+0
get_pageblock_flags and set_pageblock_flags are not used any more, this patch removes them. Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03mm: remove lru parameter from __lru_cache_add and lru_cache_add_lruMel Gorman1-4/+7
Similar to __pagevec_lru_add, this patch removes the LRU parameter from __lru_cache_add and lru_cache_add_lru as the caller does not control the exact LRU the page gets added to. lru_cache_add_lru gets renamed to lru_cache_add the name is silly without the lru parameter. With the parameter removed, it is required that the caller indicate if they want the page added to the active or inactive list by setting or clearing PageActive respectively. [akpm@linux-foundation.org: Suggested the patch] [gang.chen@asianux.com: fix used-unintialized warning] Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Chen Gang <gang.chen@asianux.com> Cc: Jan Kara <jack@suse.cz> Cc: Rik van Riel <riel@redhat.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Alexey Lyahkov <alexey.lyashkov@gmail.com> Cc: Andrew Perepechko <anserper@ya.ru> Cc: Robin Dong <sanbai@taobao.com> Cc: Theodore Tso <tytso@mit.edu> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Bernd Schubert <bernd.schubert@fastmail.fm> Cc: David Howells <dhowells@redhat.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03mm: remove lru parameter from __pagevec_lru_add and remove parts of pagevec APIMel Gorman1-33/+1
Now that the LRU to add a page to is decided at LRU-add time, remove the misleading lru parameter from __pagevec_lru_add. A consequence of this is that the pagevec_lru_add_file, pagevec_lru_add_anon and similar helpers are misleading as the caller no longer has direct control over what LRU the page is added to. Unused helpers are removed by this patch and existing users of pagevec_lru_add_file() are converted to use lru_cache_add_file() directly and use the per-cpu pagevecs instead of creating their own pagevec. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Alexey Lyahkov <alexey.lyashkov@gmail.com> Cc: Andrew Perepechko <anserper@ya.ru> Cc: Robin Dong <sanbai@taobao.com> Cc: Theodore Tso <tytso@mit.edu> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Bernd Schubert <bernd.schubert@fastmail.fm> Cc: David Howells <dhowells@redhat.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03mm: add tracepoints for LRU activation and insertionsMel Gorman1-0/+89
Andrew Perepechko reported a problem whereby pages are being prematurely evicted as the mark_page_accessed() hint is ignored for pages that are currently on a pagevec -- http://www.spinics.net/lists/linux-ext4/msg37340.html . Alexey Lyahkov and Robin Dong have also reported problems recently that could be due to hot pages reaching the end of the inactive list too quickly and be reclaimed. Rather than addressing this on a per-filesystem basis, this series aims to fix the mark_page_accessed() interface by deferring what LRU a page is added to pagevec drain time and allowing mark_page_accessed() to call SetPageActive on a pagevec page. Patch 1 adds two tracepoints for LRU page activation and insertion. Using these processes it's possible to build a model of pages in the LRU that can be processed offline. Patch 2 defers making the decision on what LRU to add a page to until when the pagevec is drained. Patch 3 searches the local pagevec for pages to mark PageActive on mark_page_accessed. The changelog explains why only the local pagevec is examined. Patches 4 and 5 tidy up the API. postmark, a dd-based test and fs-mark both single and threaded mode were run but none of them showed any performance degradation or gain as a result of the patch. Using patch 1, I built a *very* basic model of the LRU to examine offline what the average age of different page types on the LRU were in milliseconds. Of course, capturing the trace distorts the test as it's written to local disk but it does not matter for the purposes of this test. The average age of pages in milliseconds were vanilla deferdrain Average age mapped anon: 1454 1250 Average age mapped file: 127841 155552 Average age unmapped anon: 85 235 Average age unmapped file: 73633 38884 Average age unmapped buffers: 74054 116155 The LRU activity was mostly files which you'd expect for a dd-based workload. Note that the average age of buffer pages is increased by the series and it is expected this is due to the fact that the buffer pages are now getting added to the active list when drained from the pagevecs. Note that the average age of the unmapped file data is decreased as they are still added to the inactive list and are reclaimed before the buffers. There is no guarantee this is a universal win for all workloads and it would be nice if the filesystem people gave some thought as to whether this decision is generally a win or a loss. This patch: Using these tracepoints it is possible to model LRU activity and the average residency of pages of different types. This can be used to debug problems related to premature reclaim of pages of particular types. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Alexey Lyahkov <alexey.lyashkov@gmail.com> Cc: Andrew Perepechko <anserper@ya.ru> Cc: Robin Dong <sanbai@taobao.com> Cc: Theodore Tso <tytso@mit.edu> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Bernd Schubert <bernd.schubert@fastmail.fm> Cc: David Howells <dhowells@redhat.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03vmalloc: introduce remap_vmalloc_range_partialHATAYAMA Daisuke1-0/+4
We want to allocate ELF note segment buffer on the 2nd kernel in vmalloc space and remap it to user-space in order to reduce the risk that memory allocation fails on system with huge number of CPUs and so with huge ELF note segment that exceeds 11-order block size. Although there's already remap_vmalloc_range for the purpose of remapping vmalloc memory to user-space, we need to specify user-space range via vma. Mmap on /proc/vmcore needs to remap range across multiple objects, so the interface that requires vma to cover full range is problematic. This patch introduces remap_vmalloc_range_partial that receives user-space range as a pair of base address and size and can be used for mmap on /proc/vmcore case. remap_vmalloc_range is rewritten using remap_vmalloc_range_partial. [akpm@linux-foundation.org: use PAGE_ALIGNED()] Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp> Cc: Lisa Mitchell <lisa.mitchell@hp.com> Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03include/linux/mm.h: add PAGE_ALIGNED() helperAndrew Morton1-0/+3
To test whether an address is aligned to PAGE_SIZE. Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com>, Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03mmzone: note that node_size_lock should be manipulated via pgdat_resize_lock()Cody P Schafer1-0/+3
Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03mm: fix comment referring to non-existent size_seqlock, change to span_seqlockCody P Schafer1-1/+1
Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03mm: vmscan: take page buffers dirty and locked state into accountMel Gorman2-0/+4
Page reclaim keeps track of dirty and under writeback pages and uses it to determine if wait_iff_congested() should stall or if kswapd should begin writing back pages. This fails to account for buffer pages that can be under writeback but not PageWriteback which is the case for filesystems like ext3 ordered mode. Furthermore, PageDirty buffer pages can have all the buffers clean and writepage does no IO so it should not be accounted as congested. This patch adds an address_space operation that filesystems may optionally use to check if a page is really dirty or really under writeback. An implementation is provided for for buffer_heads is added and used for block operations and ext3 in ordered mode. By default the page flags are obeyed. Credit goes to Jan Kara for identifying that the page flags alone are not sufficient for ext3 and sanity checking a number of ideas on how the problem could be addressed. Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Cc: Zlatko Calusic <zcalusic@bitsync.net> Cc: dormando <dormando@rydia.net> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03mm: vmscan: block kswapd if it is encountering pages under writebackMel Gorman1-0/+8
Historically, kswapd used to congestion_wait() at higher priorities if it was not making forward progress. This made no sense as the failure to make progress could be completely independent of IO. It was later replaced by wait_iff_congested() and removed entirely by commit 258401a6 (mm: don't wait on congested zones in balance_pgdat()) as it was duplicating logic in shrink_inactive_list(). This is problematic. If kswapd encounters many pages under writeback and it continues to scan until it reaches the high watermark then it will quickly skip over the pages under writeback and reclaim clean young pages or push applications out to swap. The use of wait_iff_congested() is not suited to kswapd as it will only stall if the underlying BDI is really congested or a direct reclaimer was unable to write to the underlying BDI. kswapd bypasses the BDI congestion as it sets PF_SWAPWRITE but even if this was taken into account then it would cause direct reclaimers to stall on writeback which is not desirable. This patch sets a ZONE_WRITEBACK flag if direct reclaim or kswapd is encountering too many pages under writeback. If this flag is set and kswapd encounters a PageReclaim page under writeback then it'll assume that the LRU lists are being recycled too quickly before IO can complete and block waiting for some IO to complete. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Michal Hocko <mhocko@suse.cz> Acked-by: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Tested-by: Zlatko Calusic <zcalusic@bitsync.net> Cc: dormando <dormando@rydia.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03mm: vmscan: have kswapd writeback pages based on dirty pages encountered, ↵Mel Gorman1-0/+9
not priority Currently kswapd queues dirty pages for writeback if scanning at an elevated priority but the priority kswapd scans at is not related to the number of unqueued dirty encountered. Since commit "mm: vmscan: Flatten kswapd priority loop", the priority is related to the size of the LRU and the zone watermark which is no indication as to whether kswapd should write pages or not. This patch tracks if an excessive number of unqueued dirty pages are being encountered at the end of the LRU. If so, it indicates that dirty pages are being recycled before flusher threads can clean them and flags the zone so that kswapd will start writing pages until the zone is balanced. Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Rik van Riel <riel@redhat.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Tested-by: Zlatko Calusic <zcalusic@bitsync.net> Cc: dormando <dormando@rydia.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03mm, memcg: don't take task_lock in task_in_mem_cgroupDavid Rientjes1-4/+5
For processes that have detached their mm's, task_in_mem_cgroup() unnecessarily takes task_lock() when rcu_read_lock() is all that is necessary to call mem_cgroup_from_task(). While we're here, switch task_in_mem_cgroup() to return bool. Signed-off-by: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03mm: soft-dirty bits for user memory changes trackingPavel Emelyanov1-0/+22
The soft-dirty is a bit on a PTE which helps to track which pages a task writes to. In order to do this tracking one should 1. Clear soft-dirty bits from PTEs ("echo 4 > /proc/PID/clear_refs) 2. Wait some time. 3. Read soft-dirty bits (55'th in /proc/PID/pagemap2 entries) To do this tracking, the writable bit is cleared from PTEs when the soft-dirty bit is. Thus, after this, when the task tries to modify a page at some virtual address the #PF occurs and the kernel sets the soft-dirty bit on the respective PTE. Note, that although all the task's address space is marked as r/o after the soft-dirty bits clear, the #PF-s that occur after that are processed fast. This is so, since the pages are still mapped to physical memory, and thus all the kernel does is finds this fact out and puts back writable, dirty and soft-dirty bits on the PTE. Another thing to note, is that when mremap moves PTEs they are marked with soft-dirty as well, since from the user perspective mremap modifies the virtual memory at mremap's new address. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Glauber Costa <glommer@parallels.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03include/linux/smp.h:on_each_cpu(): switch back to a macroAndrew Morton1-12/+8
Commit f21afc25f9ed ("smp.h: Use local_irq_{save,restore}() in !SMP version of on_each_cpu()") converted on_each_cpu() to a C function. This required inclusion of irqflags.h, which broke ia64 and mn10300 (at least) due to header ordering hell. Switch on_each_cpu() back to a macro to fix this. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: David Daney <david.daney@cavium.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: <stable@vger.kernel.org> [3.10.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03Merge tag 'arm64-upstream' of ↵Linus Torvalds4-2/+8
git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64 Pull ARM64 updates from Catalin Marinas: "Main features: - KVM and Xen ports to AArch64 - Hugetlbfs and transparent huge pages support for arm64 - Applied Micro X-Gene Kconfig entry and dts file - Cache flushing improvements For arm64 huge pages support, there are x86 changes moving part of arch/x86/mm/hugetlbpage.c into mm/hugetlb.c to be re-used by arm64" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64: (66 commits) arm64: Add initial DTS for APM X-Gene Storm SOC and APM Mustang board arm64: Add defines for APM ARMv8 implementation arm64: Enable APM X-Gene SOC family in the defconfig arm64: Add Kconfig option for APM X-Gene SOC family arm64/Makefile: provide vdso_install target ARM64: mm: THP support. ARM64: mm: Raise MAX_ORDER for 64KB pages and THP. ARM64: mm: HugeTLB support. ARM64: mm: Move PTE_PROT_NONE bit. ARM64: mm: Make PAGE_NONE pages read only and no-execute. ARM64: mm: Restore memblock limit when map_mem finished. mm: thp: Correct the HPAGE_PMD_ORDER check. x86: mm: Remove general hugetlb code from x86. mm: hugetlb: Copy general hugetlb code from x86 to mm. x86: mm: Remove x86 version of huge_pmd_share. mm: hugetlb: Copy huge_pmd_share from x86 to mm. arm64: KVM: document kernel object mappings in HYP arm64: KVM: MAINTAINERS update arm64: KVM: userspace API documentation arm64: KVM: enable initialization of a 32bit vcpu ...
2013-07-03Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-armLinus Torvalds1-1/+1
Pull ARM updates from Russell King: "This contains the usual updates from other people (listed below) and the usual random muddle of miscellaneous ARM updates which cover some low priority bug fixes and performance improvements. I've started to put the pull request wording into the merge commits, which are: - NoMMU stuff: This includes the following series sent earlier to the list: - nommu-fixes - R7 Support - MPU support I've left out the ARCH_MULTIPLATFORM/!MMU stuff that Arnd and I were discussing today until we've reached a conclusion/that's had some more review. This is rebased (and re-tested) on your devel-stable branch because otherwise there were going to be conflicts with Uwe's V7M work now that you've merged that. I've included the fix for limiting MPU to CPU_V7. - Huge page support These changes bring both HugeTLB support and Transparent HugePage (THP) support to ARM. Only long descriptors (LPAE) are supported in this series. The code has been tested on an Arndale board (Exynos 5250). - LPAE updates Please pull these miscellaneous LPAE fixes I've been collecting for a while now for 3.11. They've been tested and reviewed by quite a few people, and most of the patches are pretty trivial. -- Will Deacon. - arch_timer cleanups Please pull these arch_timer cleanups I've been holding onto for a while. They're the same as my last posting, but have been rebased to v3.10-rc3. - mpidr linearisation (multiprocessor id register - identifies which CPU number we are in the system) This patch series that implements MPIDR linearization through a simple hashing algorithm and updates current cpu_{suspend}/{resume} code to use the newly created hash structures to retrieve context pointers. It represents a stepping stone for the implementation of power management code on forthcoming multi-cluster ARM systems. It has been tested on TC2 (dual cluster A15xA7 system), iMX6q, OMAP4 and Tegra, with processors hitting low-power states requiring warm-boot resume through the cpu_resume code path" * 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (77 commits) ARM: 7775/1: mm: Remove do_sect_fault from LPAE code ARM: 7777/1: Avoid extra calls to the C compiler ARM: 7774/1: Fix dtb dependency to use order-only prerequisites ARM: 7770/1: remove residual ARMv2 support from decompressor ARM: 7769/1: Cortex-A15: fix erratum 798181 implementation ARM: 7768/1: prevent risks of out-of-bound access in ASID allocator ARM: 7767/1: let the ASID allocator handle suspended animation ARM: 7766/1: versatile: don't mark pen as __INIT ARM: 7765/1: perf: Record the user-mode PC in the call chain. ARM: 7735/2: Preserve the user r/w register TPIDRURW on context switch and fork ARM: kernel: implement stack pointer save array through MPIDR hashing ARM: kernel: build MPIDR hash function data structure ARM: mpu: Ensure that MPU depends on CPU_V7 ARM: mpu: protect the vectors page with an MPU region ARM: mpu: Allow enabling of the MPU via kconfig ARM: 7758/1: introduce config HAS_BANDGAP ARM: 7757/1: mm: don't flush icache in switch_mm with hardware broadcasting ARM: 7751/1: zImage: don't overwrite ourself with a page table ARM: 7749/1: spinlock: retry trylock operation if strex fails on free lock ARM: 7748/1: oabi: handle faults when loading swi instruction from userspace ...
2013-07-03Merge branch 'for-linus' of ↵Linus Torvalds4-32/+40
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull second set of VFS changes from Al Viro: "Assorted f_pos race fixes, making do_splice_direct() safe to call with i_mutex on parent, O_TMPFILE support, Jeff's locks.c series, ->d_hash/->d_compare calling conventions changes from Linus, misc stuff all over the place." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits) Document ->tmpfile() ext4: ->tmpfile() support vfs: export lseek_execute() to modules lseek_execute() doesn't need an inode passed to it block_dev: switch to fixed_size_llseek() cpqphp_sysfs: switch to fixed_size_llseek() tile-srom: switch to fixed_size_llseek() proc_powerpc: switch to fixed_size_llseek() ubi/cdev: switch to fixed_size_llseek() pci/proc: switch to fixed_size_llseek() isapnp: switch to fixed_size_llseek() lpfc: switch to fixed_size_llseek() locks: give the blocked_hash its own spinlock locks: add a new "lm_owner_key" lock operation locks: turn the blocked_list into a hashtable locks: convert fl_link to a hlist_node locks: avoid taking global lock if possible when waking up blocked waiters locks: protect most of the file_lock handling with i_lock locks: encapsulate the fl_link list handling locks: make "added" in __posix_lock_file a bool ...
2013-07-03vfs: export lseek_execute() to modulesJie Liu1-0/+1
For those file systems(btrfs/ext4/ocfs2/tmpfs) that support SEEK_DATA/SEEK_HOLE functions, we end up handling the similar matter in lseek_execute() to update the current file offset to the desired offset if it is valid, ceph also does the simliar things at ceph_llseek(). To reduce the duplications, this patch make lseek_execute() public accessible so that we can call it directly from the underlying file systems. Thanks Dave Chinner for this suggestion. [AV: call it vfs_setpos(), don't bring the removed 'inode' argument back] v2->v1: - Add kernel-doc comments for lseek_execute() - Call lseek_execute() in ceph->llseek() Signed-off-by: Jie Liu <jeff.liu@oracle.com> Cc: Dave Chinner <dchinner@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <andi@firstfloor.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Chris Mason <chris.mason@fusionio.com> Cc: Josef Bacik <jbacik@fusionio.com> Cc: Ben Myers <bpm@sgi.com> Cc: Ted Tso <tytso@mit.edu> Cc: Hugh Dickins <hughd@google.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Sage Weil <sage@inktank.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-07-02Merge branch 'for-3.11-cpuset' of ↵Linus Torvalds1-1/+8
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cpuset changes from Tejun Heo: "cpuset has always been rather odd about its configurations - a cgroup right after creation didn't allow any task executions before configuration, changing configuration in the parent modifies the descendants irreversibly and so on. These behaviors are inherently nasty and almost hostile against sharing the hierarchy with other controllers making it very difficult to use in unified hierarchy. Li is currently in the process of updating the behaviors for __DEVEL__sane_behavior which is the bulk of changes in this pull request. It isn't complete yet and the behaviors will change further but all changes are gated behind sane_behavior. In the process, the rather hairy work-item punting which was used to work around the limitations of cgroup descendant iterator was simplified." * 'for-3.11-cpuset' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cpuset: rename @cont to @cgrp cpuset: fix to migrate mm correctly in a corner case cpuset: allow to move tasks to empty cpusets cpuset: allow to keep tasks in empty cpusets cpuset: introduce effective_{cpumask|nodemask}_cpuset() cpuset: record old_mems_allowed in struct cpuset cpuset: remove async hotplug propagation work cpuset: let hotplug propagation work wait for task attaching cpuset: re-structure update_cpumask() a bit cpuset: remove cpuset_test_cpumask() cpuset: remove unnecessary variable in cpuset_attach() cpuset: cleanup guarantee_online_{cpus|mems}() cpuset: remove redundant check in cpuset_cpus_allowed_fallback()
2013-07-02Merge branch 'for-3.11' of ↵Linus Torvalds1-91/+131
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup changes from Tejun Heo: "This pull request contains the following changes. - cgroup_subsys_state (css) reference counting has been converted to percpu-ref. css is what each resource controller embeds into its own control structure and perform reference count against. It may be used in hot paths of various subsystems and is similar to module refcnt in that aspect. For example, block-cgroup's css refcnting was showing up a lot in Mikulaus's device-mapper scalability work and this should alleviate it. - cgroup subtree iterator has been updated so that RCU read lock can be released after grabbing reference. This allows simplifying its users which requires blocking which used to build iteration list under RCU read lock and then traverse it outside. This pull request contains simplification of cgroup core and device-cgroup. A separate pull request will update cpuset. - Fixes for various bugs including corner race conditions and RCU usage bugs. - A lot of cleanups and some prepartory work for the planned unified hierarchy support." * 'for-3.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (48 commits) cgroup: CGRP_ROOT_SUBSYS_BOUND should also be ignored when mounting an existing hierarchy cgroup: CGRP_ROOT_SUBSYS_BOUND should be ignored when comparing mount options cgroup: fix deadlock on cgroup_mutex via drop_parsed_module_refcounts() cgroup: always use RCU accessors for protected accesses cgroup: fix RCU accesses around task->cgroups cgroup: fix RCU accesses to task->cgroups cgroup: grab cgroup_mutex in drop_parsed_module_refcounts() cgroup: fix cgroupfs_root early destruction path cgroup: reserve ID 0 for dummy_root and 1 for unified hierarchy cgroup: implement for_each_[builtin_]subsys() cgroup: move init_css_set initialization inside cgroup_mutex cgroup: s/for_each_subsys()/for_each_root_subsys()/ cgroup: clean up find_css_set() and friends cgroup: remove cgroup->actual_subsys_mask cgroup: prefix global variables with "cgroup_" cgroup: convert CFTYPE_* flags to enums cgroup: rename cont to cgrp cgroup: clean up cgroup_serial_nr_cursor cgroup: convert cgroup_cft_commit() to use cgroup_for_each_descendant_pre() cgroup: make serial_nr_cursor available throughout cgroup.c ...
2013-07-02Merge branch 'for-3.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds1-0/+35
Pull workqueue changes from Tejun Heo: "Surprisingly, Lai and I didn't break too many things implementing custom pools and stuff last time around and there aren't any follow-up changes necessary at this point. The only change in this pull request is Viresh's patches to make some per-cpu workqueues to behave as unbound workqueues dependent on a boot param whose default can be configured via a config option. This leads to higher processing overhead / lower bandwidth as more work items are bounced across CPUs; however, it can lead to noticeable powersave in certain configurations - ~10% w/ idlish constant workload on a big.LITTLE configuration according to Viresh. This is because per-cpu workqueues interfere with how the scheduler perceives whether or not each CPU is idle by forcing pinned tasks on them, which makes the scheduler's power-aware scheduling decisions less effective. Its effectiveness is likely less pronounced on homogenous configurations and this type of optimization can probably be made automatic; however, the changes are pretty minimal and the affected workqueues are clearly marked, so it's an easy gain for some configurations for the time being with pretty unintrusive changes." * 'for-3.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: fbcon: queue work on power efficient wq block: queue work on power efficient wq PHYLIB: queue work on system_power_efficient_wq workqueue: Add system wide power_efficient workqueues workqueues: Introduce new flag WQ_POWER_EFFICIENT for power oriented workqueues
2013-07-02Merge branch 'for-3.11' of ↵Linus Torvalds1-0/+174
git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu Pull per-cpu changes from Tejun Heo: "This pull request contains Kent's per-cpu reference counter. It has gone through several iterations since the last time and the dynamic allocation is gone. The usual usage is relatively straight-forward although async kill confirm interface, which is not used int most cases, is somewhat icky. There also are some interface concerns - e.g. I'm not sure about passing in @relesae callback during init as that becomes funny when we later implement synchronous kill_and_drain - but nothing too serious and it's quite useable now. cgroup_subsys_state refcnting has already been converted and we should convert module refcnt (Kent?)" * 'for-3.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: percpu-refcount: use RCU-sched insted of normal RCU percpu-refcount: implement percpu_tryget() along with percpu_ref_kill_and_confirm() percpu-refcount: implement percpu_ref_cancel_init() percpu-refcount: add __must_check to percpu_ref_init() and don't use ACCESS_ONCE() in percpu_ref_kill_rcu() percpu-refcount: cosmetic updates percpu-refcount: consistently use plain (non-sched) RCU percpu-refcount: Don't use silly cmpxchg() percpu: implement generic percpu refcounting
2013-07-02Merge branch 'x86-tracing-for-linus' of ↵Linus Torvalds4-0/+14
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 tracing updates from Ingo Molnar: "This tree adds IRQ vector tracepoints that are named after the handler and which output the vector #, based on a zero-overhead approach that relies on changing the IDT entries, by Seiji Aguchi. The new tracepoints look like this: # perf list | grep -i irq_vector irq_vectors:local_timer_entry [Tracepoint event] irq_vectors:local_timer_exit [Tracepoint event] irq_vectors:reschedule_entry [Tracepoint event] irq_vectors:reschedule_exit [Tracepoint event] irq_vectors:spurious_apic_entry [Tracepoint event] irq_vectors:spurious_apic_exit [Tracepoint event] irq_vectors:error_apic_entry [Tracepoint event] irq_vectors:error_apic_exit [Tracepoint event] [...]" * 'x86-tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/tracing: Add config option checking to the definitions of mce handlers trace,x86: Do not call local_irq_save() in load_current_idt() trace,x86: Move creation of irq tracepoints from apic.c to irq.c x86, trace: Add irq vector tracepoints x86: Rename variables for debugging x86, trace: Introduce entering/exiting_irq() tracing: Add DEFINE_EVENT_FN() macro
2013-07-02Merge branch 'x86-efi-for-linus' of ↵Linus Torvalds1-14/+14
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 EFI changes from Ingo Molnar: "Two fixes that should in principle increase robustness of our interaction with the EFI firmware, and a cleanup" * 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, efi: retry ExitBootServices() on failure efi: Convert runtime services function ptrs UEFI: Don't pass boot services regions to SetVirtualAddressMap()
2013-07-02Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds1-0/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull asm/x86 changes from Ingo Molnar: "Misc changes, with a bigger processor-flags cleanup/reorganization by Peter Anvin" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, asm, cleanup: Replace open-coded control register values with symbolic x86, processor-flags: Fix the datatypes and add bit number defines x86: Rename X86_CR4_RDWRGSFS to X86_CR4_FSGSBASE x86, flags: Rename X86_EFLAGS_BIT1 to X86_EFLAGS_FIXED linux/const.h: Add _BITUL() and _BITULL() x86/vdso: Convert use of typedef ctl_table to struct ctl_table x86: __force_order doesn't need to be an actual variable
2013-07-02Merge branch 'sched-mm-for-linus' of ↵Linus Torvalds2-10/+7
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull voluntary preemption fixes from Ingo Molnar: "This tree contains a speedup which is achieved through better might_sleep()/might_fault() preemption point annotations for uaccess functions, by Michael S Tsirkin: 1. The only reason uaccess routines might sleep is if they fault. Make this explicit for all architectures. 2. A voluntary preemption point in uaccess functions means compiler can't inline them efficiently, this breaks assumptions that they are very fast and small that e.g. net code seems to make. Remove this preemption point so behaviour matches with what callers assume. 3. Accesses (e.g through socket ops) to kernel memory with KERNEL_DS like net/sunrpc does will never sleep. Remove an unconditinal might_sleep() in the might_fault() inline in kernel.h (used when PROVE_LOCKING is not set). 4. Accesses with pagefault_disable() return EFAULT but won't cause caller to sleep. Check for that and thus avoid might_sleep() when PROVE_LOCKING is set. These changes offer a nice speedup for CONFIG_PREEMPT_VOLUNTARY=y kernels, here's a network bandwidth measurement between a virtual machine and the host: before: incoming: 7122.77 Mb/s outgoing: 8480.37 Mb/s after: incoming: 8619.24 Mb/s [ +21.0% ] outgoing: 9455.42 Mb/s [ +11.5% ] I kept these changes in a separate tree, separate from scheduler changes, because it's a mixed MM and scheduler topic" * 'sched-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: mm, sched: Allow uaccess in atomic with pagefault_disable() mm, sched: Drop voluntary schedule from might_fault() x86: uaccess s/might_sleep/might_fault/ tile: uaccess s/might_sleep/might_fault/ powerpc: uaccess s/might_sleep/might_fault/ mn10300: uaccess s/might_sleep/might_fault/ microblaze: uaccess s/might_sleep/might_fault/ m32r: uaccess s/might_sleep/might_fault/ frv: uaccess s/might_sleep/might_fault/ arm64: uaccess s/might_sleep/might_fault/ asm-generic: uaccess s/might_sleep/might_fault/
2013-07-02Merge branch 'sched-core-for-linus' of ↵Linus Torvalds5-11/+6
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "The main changes: - load-calculation cleanups and improvements, by Alex Shi - various nohz related tidying up of statisics, by Frederic Weisbecker - factor out /proc functions to kernel/sched/proc.c, by Paul Gortmaker - simplify the RT policy scheduler, by Kirill Tkhai - various fixes and cleanups" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (42 commits) sched/debug: Remove CONFIG_FAIR_GROUP_SCHED mask sched/debug: Fix formatting of /proc/<PID>/sched sched: Fix typo in struct sched_avg member description sched/fair: Fix typo describing flags in enqueue_entity sched/debug: Add load-tracking statistics to task sched: Change get_rq_runnable_load() to static and inline sched/tg: Remove tg.load_weight sched/cfs_rq: Change atomic64_t removed_load to atomic_long_t sched/tg: Use 'unsigned long' for load variable in task group sched: Change cfs_rq load avg to unsigned long sched: Consider runnable load average in move_tasks() sched: Compute runnable load avg in cpu_load and cpu_avg_load_per_task sched: Update cpu load after task_tick sched: Fix sleep time double accounting in enqueue entity sched: Set an initial value of runnable avg for new forked task sched: Move a few runnable tg variables into CONFIG_SMP Revert "sched: Introduce temporary FAIR_GROUP_SCHED dependency for load-tracking" sched: Don't mix use of typedef ctl_table and struct ctl_table sched: Remove WARN_ON(!sd) from init_sched_groups_power() sched: Fix memory leakage in build_sched_groups() ...
2013-07-02Merge branch 'perf-core-for-linus' of ↵Linus Torvalds3-5/+65
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Ingo Molnar: "Kernel improvements: - watchdog driver improvements by Li Zefan - Power7 CPI stack events related improvements by Sukadev Bhattiprolu - event multiplexing via hrtimers and other improvements by Stephane Eranian - kernel stack use optimization by Andrew Hunter - AMD IOMMU uncore PMU support by Suravee Suthikulpanit - NMI handling rate-limits by Dave Hansen - various hw_breakpoint fixes by Oleg Nesterov - hw_breakpoint overflow period sampling and related signal handling fixes by Jiri Olsa - Intel Haswell PMU support by Andi Kleen Tooling improvements: - Reset SIGTERM handler in workload child process, fix from David Ahern. - Makefile reorganization, prep work for Kconfig patches, from Jiri Olsa. - Add automated make test suite, from Jiri Olsa. - Add --percent-limit option to 'top' and 'report', from Namhyung Kim. - Sorting improvements, from Namhyung Kim. - Expand definition of sysfs format attribute, from Michael Ellerman. Tooling fixes: - 'perf tests' fixes from Jiri Olsa. - Make Power7 CPI stack events available in sysfs, from Sukadev Bhattiprolu. - Handle death by SIGTERM in 'perf record', fix from David Ahern. - Fix printing of perf_event_paranoid message, from David Ahern. - Handle realloc failures in 'perf kvm', from David Ahern. - Fix divide by 0 in variance, from David Ahern. - Save parent pid in thread struct, from David Ahern. - Handle JITed code in shared memory, from Andi Kleen. - Fixes for 'perf diff', from Jiri Olsa. - Remove some unused struct members, from Jiri Olsa. - Add missing liblk.a dependency for python/perf.so, fix from Jiri Olsa. - Respect CROSS_COMPILE in liblk.a, from Rabin Vincent. - No need to do locking when adding hists in perf report, only 'top' needs that, from Namhyung Kim. - Fix alignment of symbol column in in the hists browser (top, report) when -v is given, from NAmhyung Kim. - Fix 'perf top' -E option behavior, from Namhyung Kim. - Fix bug in isupper() and islower(), from Sukadev Bhattiprolu. - Fix compile errors in bp_signal 'perf test', from Sukadev Bhattiprolu. ... and more things" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (102 commits) perf/x86: Disable PEBS-LL in intel_pmu_pebs_disable() perf/x86: Fix shared register mutual exclusion enforcement perf/x86/intel: Support full width counting x86: Add NMI duration tracepoints perf: Drop sample rate when sampling is too slow x86: Warn when NMI handlers take large amounts of time hw_breakpoint: Introduce "struct bp_cpuinfo" hw_breakpoint: Simplify *register_wide_hw_breakpoint() hw_breakpoint: Introduce cpumask_of_bp() hw_breakpoint: Simplify the "weight" usage in toggle_bp_slot() paths hw_breakpoint: Simplify list/idx mess in toggle_bp_slot() paths perf/x86/intel: Add mem-loads/stores support for Haswell perf/x86/intel: Support Haswell/v4 LBR format perf/x86/intel: Move NMI clearing to end of PMI handler perf/x86/intel: Add Haswell PEBS support perf/x86/intel: Add simple Haswell PMU support perf/x86/intel: Add Haswell PEBS record support perf/x86/intel: Fix sparse warning perf/x86/amd: AMD IOMMU Performance Counter PERF uncore PMU implementation perf/x86/amd: Add IOMMU Performance Counter resource management ...
2013-07-02Merge branch 'irq-core-for-linus' of ↵Linus Torvalds2-1/+64
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core irq changes from Ingo Molnar: "The main changes: - generic-irqchip driver additions, cleanups and fixes - 3 new irqchip drivers: ARMv7-M NVIC, TB10x and Marvell Orion SoCs - irq_get_trigger_type() simplification and cross-arch cleanup - various cleanups, simplifications - documentation updates" * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (26 commits) softirq: Use _RET_IP_ genirq: Add the generic chip to the genirq docbook genirq: generic-chip: Export some irq_gc_ functions genirq: Fix can_request_irq() for IRQs without an action irqchip: exynos-combiner: Staticize combiner_init irqchip: Add support for ARMv7-M NVIC irqchip: Add TB10x interrupt controller driver irqdomain: Use irq_get_trigger_type() to get IRQ flags MIPS: octeon: Use irq_get_trigger_type() to get IRQ flags arm: orion: Use irq_get_trigger_type() to get IRQ flags mfd: stmpe: use irq_get_trigger_type() to get IRQ flags mfd: twl4030-irq: Use irq_get_trigger_type() to get IRQ flags gpio: mvebu: Use irq_get_trigger_type() to get IRQ flags genirq: Add irq_get_trigger_type() to get IRQ flags genirq: Irqchip: document gcflags arg of irq_alloc_domain_generic_chips genirq: Set irq thread to RT priority on creation irqchip: Add support for Marvell Orion SoCs genirq: Add kerneldoc for irq_disable. genirq: irqchip: Add mask to block out invalid irqs genirq: Generic chip: Add linear irq domain support ...
2013-07-02Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds5-85/+9
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU updates from Ingo Molnar: "The major changes: - Simplify RCU's grace-period and callback processing based on the new numbering for callbacks. - Removal of TINY_PREEMPT_RCU in favor of TREE_PREEMPT_RCU for single-CPU low-latency systems. - SRCU-related changes and fixes. - Miscellaneous fixes, including converting a few remaining printk() calls to pr_*(). - Documentation updates" * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits) rcu: Shrink TINY_RCU by reworking CPU-stall ifdefs rcu: Shrink TINY_RCU by moving exit_rcu() rcu: Remove TINY_PREEMPT_RCU tracing documentation rcu: Consolidate rcutiny_plugin.h ifdefs rcu: Remove rcu_preempt_note_context_switch() rcu: Remove the CONFIG_TINY_RCU ifdefs in rcutiny.h rcu: Remove check_cpu_stall_preempt() rcu: Simplify RCU_TINY RCU callback invocation rcu: Remove rcu_preempt_process_callbacks() rcu: Remove rcu_preempt_remove_callbacks() rcu: Remove rcu_preempt_check_callbacks() rcu: Remove show_tiny_preempt_stats() rcu: Remove TINY_PREEMPT_RCU powerpc,kvm: fix imbalance srcu_read_[un]lock() rcu: Remove srcu_read_lock_raw() and srcu_read_unlock_raw(). rcu: Apply Dave Jones's NOCB Kconfig help feedback rcu: Merge adjacent identical ifdefs rcu: Drive quiescent-state-forcing delay from HZ rcu: Remove "Experimental" flags kthread: Add kworker kthreads to OS-jitter documentation ...
2013-07-02Merge branch 'core-mutexes-for-linus' of ↵Linus Torvalds5-14/+372
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull WW mutex support from Ingo Molnar: "This tree adds support for wound/wait style locks, which the graphics guys would like to make use of in the TTM graphics subsystem. Wound/wait mutexes are used when other multiple lock acquisitions of a similar type can be done in an arbitrary order. The deadlock handling used here is called wait/wound in the RDBMS literature: The older tasks waits until it can acquire the contended lock. The younger tasks needs to back off and drop all the locks it is currently holding, ie the younger task is wounded. See this LWN.net description of W/W mutexes: https://lwn.net/Articles/548909/ The comments there outline specific usecases for this facility (which have already been implemented for the DRM tree). Also see Documentation/ww-mutex-design.txt for more details" * 'core-mutexes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: locking-selftests: Handle unexpected failures more strictly mutex: Add more w/w tests to test EDEADLK path handling mutex: Add more tests to lib/locking-selftest.c mutex: Add w/w tests to lib/locking-selftest.c mutex: Add w/w mutex slowpath debugging mutex: Add support for wound/wait style locks arch: Make __mutex_fastpath_lock_retval return whether fastpath succeeded or not