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2010-05-27numa: update Documentation/vm/numa, add memoryless node infoLee Schermerhorn1-39/+147
Kamezawa Hiroyuki requested documentation for the numa_mem_id() and slab related changes. He suggested Documentation/vm/numa for this documentation. Looking at this file, it seems to me to be hopelessly out of date relative to current Linux NUMA support. At the risk of going down a rathole, I have made an attempt to rewrite the doc at a slightly higher level [I think] and provide pointers to other in-tree documents and out-of-tree man pages that cover the details. Let the games begin. Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Tejun Heo <tj@kernel.org> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Nick Piggin <npiggin@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Eric Whitney <eric.whitney@hp.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-24Documentation/vm: use better value for MAP_HUGETLBCarlo Marcelo Arenas Belon1-1/+1
documentation: slightly more correct value for MAP_HUGETLB in map_hugetlb.c still not correct for alpha, mips, parisc or xtensa but working out of the box in the most common architectures without having to deal with complicated macros or including architecture specific headers. Signed-off-by: Carlo Marcelo Arenas Belon <carenas@sajinet.com.pe> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-23Documentation/: it's -> its where appropriateFrancis Galiegue1-2/+2
Fix obvious cases of "it's" being used when "its" was meant. Signed-off-by: Francis Galiegue <fgaliegue@gmail.com> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-03-12Documentation/vm/: split txt and source filesRandy Dunlap6-173/+209
Documentation/vm/: Expose example and tool source files in the Documentation/ directory in their own files instead of being buried (almost hidden) in readme/txt files. This should help to prevent bitrot. This will make them more visible/usable to users who may need to use them, to developers who may need to test with them, and to anyone who would fix/update them if they were more visible. Also, if any of these possibly should not be in the kernel tree at all, it will be clearer that they are here and we can discuss if they should be removed. Also build the recently-added map_hugetlb.c. Make several functions static to prevent linker warnings. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Acked-by: Eric B Munson <ebmunson@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-02-26failslab: add ability to filter slab cachesDmitry Monakhov1-0/+1
This patch allow to inject faults only for specific slabs. In order to preserve default behavior cache filter is off by default (all caches are faulty). One may define specific set of slabs like this: # mark skbuff_head_cache as faulty echo 1 > /sys/kernel/slab/skbuff_head_cache/failslab # Turn on cache filter (off by default) echo 1 > /sys/kernel/debug/failslab/cache-filter # Turn on fault injection echo 1 > /sys/kernel/debug/failslab/times echo 1 > /sys/kernel/debug/failslab/probability Acked-by: David Rientjes <rientjes@google.com> Acked-by: Akinobu Mita <akinobu.mita@gmail.com> Acked-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2009-12-16HWPOISON: Use correct name for MADV_HWPOISON in documentationAndi Kleen1-1/+1
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16HWPOISON: add memory cgroup filterAndi Kleen1-0/+16
The hwpoison test suite need to inject hwpoison to a collection of selected task pages, and must not touch pages not owned by them and thus kill important system processes such as init. (But it's OK to mis-hwpoison free/unowned pages as well as shared clean pages. Mis-hwpoison of shared dirty pages will kill all tasks, so the test suite will target all or non of such tasks in the first place.) The memory cgroup serves this purpose well. We can put the target processes under the control of a memory cgroup, and tell the hwpoison injection code to only kill pages associated with some active memory cgroup. The prerequisite for doing hwpoison stress tests with mem_cgroup is, the mem_cgroup code tracks task pages _accurately_ (unless page is locked). Which we believe is/should be true. The benefits are simplification of hwpoison injector code. Also the mem_cgroup code will automatically be tested by hwpoison test cases. The alternative interfaces pin-pfn/unpin-pfn can also delegate the (process and page flags) filtering functions reliably to user space. However prototype implementation shows that this scheme adds more complexity than we wanted. Example test case: mkdir /cgroup/hwpoison usemem -m 100 -s 1000 & echo `jobs -p` > /cgroup/hwpoison/tasks memcg_ino=$(ls -id /cgroup/hwpoison | cut -f1 -d' ') echo $memcg_ino > /debug/hwpoison/corrupt-filter-memcg page-types -p `pidof init` --hwpoison # shall do nothing page-types -p `pidof usemem` --hwpoison # poison its pages [AK: Fix documentation] [Add fix for problem noticed by Li Zefan <lizf@cn.fujitsu.com>; dentry in the css could be NULL] CC: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> CC: Hugh Dickins <hugh.dickins@tiscali.co.uk> CC: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> CC: Balbir Singh <balbir@linux.vnet.ibm.com> CC: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> CC: Li Zefan <lizf@cn.fujitsu.com> CC: Paul Menage <menage@google.com> CC: Nick Piggin <npiggin@suse.de> CC: Andi Kleen <andi@firstfloor.org> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16HWPOISON: add page flags filterWu Fengguang1-0/+10
When specified, only poison pages if ((page_flags & mask) == value). - corrupt-filter-flags-mask - corrupt-filter-flags-value This allows stress testing of many kinds of pages. Strictly speaking, the buddy pages requires taking zone lock, to avoid setting PG_hwpoison on a "was buddy but now allocated to someone" page. However we can just do nothing because we set PG_locked in the beginning, this prevents the page allocator from allocating it to someone. (It will BUG() on the unexpected PG_locked, which is fine for hwpoison testing.) [AK: Add select PROC_PAGE_MONITOR to satisfy dependency] CC: Nick Piggin <npiggin@suse.de> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16HWPOISON: limit hwpoison injector to known page typesWu Fengguang1-1/+2
__memory_failure()'s workflow is set PG_hwpoison //... unset PG_hwpoison if didn't pass hwpoison filter That could kill unrelated process if it happens to page fault on the page with the (temporary) PG_hwpoison. The race should be big enough to appear in stress tests. Fix it by grabbing the page and checking filter at inject time. This also avoids the very noisy "Injecting memory failure..." messages. - we don't touch madvise() based injection, because the filters are generally not necessary for it. - if we want to apply the filters to h/w aided injection, we'd better to rearrange the logic in __memory_failure() instead of this patch. AK: fix documentation, use drain all, cleanups CC: Haicheng Li <haicheng.li@intel.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16HWPOISON: add fs/device filtersWu Fengguang1-0/+7
Filesystem data/metadata present the most tricky-to-isolate pages. It requires careful code review and stress testing to get them right. The fs/device filter helps to target the stress tests to some specific filesystem pages. The filter condition is block device's major/minor numbers: - corrupt-filter-dev-major - corrupt-filter-dev-minor When specified (non -1), only page cache pages that belong to that device will be poisoned. The filters are checked reliably on the locked and refcounted page. Haicheng: clear PG_hwpoison and drop bad page count if filter not OK AK: Add documentation CC: Haicheng Li <haicheng.li@intel.com> CC: Nick Piggin <npiggin@suse.de> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16HWPOISON: Add unpoisoning supportWu Fengguang1-2/+14
The unpoisoning interface is useful for stress testing tools to reclaim poisoned pages (to prevent OOM) There is no hardware level unpoisioning, so this cannot be used for real memory errors, only for software injected errors. Note that it may leak pages silently - those who have been removed from LRU cache, but not isolated from page cache/swap cache at hwpoison time. Especially the stress test of dirty swap cache pages shall reboot system before exhausting memory. AK: Fix comments, add documentation, add printks, rename symbol Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16page-types: add standard GPL license headerWu Fengguang1-2/+13
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-15ksm: remove unswappable max_kernel_pagesHugh Dickins1-15/+7
Now that ksm pages are swappable, and the known holes plugged, remove mention of unswappable kernel pages from KSM documentation and comments. Remove the totalram_pages/4 initialization of max_kernel_pages. In fact, remove max_kernel_pages altogether - we can reinstate it if removal turns out to break someone's script; but if we later want to limit KSM's memory usage, limiting the stable nodes would not be an effective approach. Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: Izik Eidus <ieidus@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Chris Wright <chrisw@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15hugetlb: handle memory hot-plug eventsLee Schermerhorn1-1/+2
Register per node hstate attributes only for nodes with memory. As suggested by David Rientjes. With Memory Hotplug, memory can be added to a memoryless node and a node with memory can become memoryless. Therefore, add a memory on/off-line notifier callback to [un]register a node's attributes on transition to/from memoryless state. N.B., Only tested build, boot, libhugetlbfs regression. i.e., no memory hotplug testing. Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Reviewed-by: Andi Kleen <andi@firstfloor.org> Acked-by: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Nishanth Aravamudan <nacc@us.ibm.com> Cc: Adam Litke <agl@us.ibm.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: Eric Whitney <eric.whitney@hp.com> Cc: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15hugetlb: use only nodes with memory for huge pagesLee Schermerhorn1-6/+6
Register per node hstate sysfs attributes only for nodes with memory. Global replacement of 'all online nodes" with "all nodes with memory" in mm/hugetlb.c. Suggested by David Rientjes. A subsequent patch will handle adding/removing of per node hstate sysfs attributes when nodes transition to/from memoryless state via memory hotplug. NOTE: this patch has not been tested with memoryless nodes. Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Reviewed-by: Andi Kleen <andi@firstfloor.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Nishanth Aravamudan <nacc@us.ibm.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Adam Litke <agl@us.ibm.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: Eric Whitney <eric.whitney@hp.com> Cc: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15hugetlb: update hugetlb documentation for NUMA controlsLee Schermerhorn1-85/+176
Update the kernel huge tlb documentation to describe the numa memory policy based huge page management. Additionaly, the patch includes a fair amount of rework to improve consistency, eliminate duplication and set the context for documenting the memory policy interaction. Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Andi Kleen <andi@firstfloor.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Nishanth Aravamudan <nacc@us.ibm.com> Cc: Adam Litke <agl@us.ibm.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: Eric Whitney <eric.whitney@hp.com> Cc: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15page-types: exit early when invoked with -d|--describeAlex Chiang1-2/+1
On a system with large amount of memory (256GB), invoking page-types can take quite a long time, which is unreasonable considering the user only wants a description of the flags: # time ./page-types -d 0x10 0x0000000000000010 ____D_____________________________ dirty real 0m34.285s user 0m1.966s sys 0m32.313s This is because we still walk the entire address range. Exiting early seems like a reasonble solution: # time ./page-types -d 0x10 0x0000000000000010 ____D_____________________________ dirty real 0m0.007s user 0m0.001s sys 0m0.005s Signed-off-by: Alex Chiang <achiang@hp.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Haicheng Li <haicheng.li@intel.com> Acked-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15page-types: whitespace alignmentAlex Chiang1-23/+23
Align the output when page-type -h is invoked. Signed-off-by: Alex Chiang <achiang@hp.com> Acked-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15page-types: learn to describe flags directly from command lineAlex Chiang1-1/+20
Teach page-types to describe page flags directly from the command line. Why is this useful? For instance, if you're using memory hotplug and see this in /var/log/messages: kernel: removing from LRU failed 3836dd0/1/1e00000000000010 It would be nice to decode those page flags without staring at the source. Example usage and output: # Documentation/vm/page-types -d 0x10 0x0000000000000010 ____D_____________________________ dirty # Documentation/vm/page-types -d anon 0x0000000000001000 ____________a_____________________ anonymous # Documentation/vm/page-types -d anon,0x10 0x0000000000001010 ____D_______a_____________________ dirty,anonymous [achiang@hp.com: documentation] Signed-off-by: Alex Chiang <achiang@hp.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Haicheng Li <haicheng.li@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15page-types: unsigned cannot be less than 0 in add_page()Roel Kluin1-1/+1
If not signed, testing of the read() return value in this function will not work. Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15page-types: constify read only arraysTommi Rantala1-3/+3
Signed-off-by: Tommi Rantala <tt.rantala@gmail.com> Cc: Randy Dunlap <rdunlap@xenotime.net> 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>
2009-12-07Merge branch 'for-next' into for-linusJiri Kosina2-2/+2
Conflicts: kernel/irq/chip.c
2009-12-04doc: Fix a typo in slub.txt.Justin P. Mattock1-1/+1
Signed-off-by: Justin P. Mattock <justinmattock@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-12-04tree-wide: fix assorted typos all over the placeAndré Goddard Rosa1-1/+1
That is "success", "unknown", "through", "performance", "[re|un]mapping" , "access", "default", "reasonable", "[con]currently", "temperature" , "channel", "[un]used", "application", "example","hierarchy", "therefore" , "[over|under]flow", "contiguous", "threshold", "enough" and others. Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-11-17Merge branch 'hostprogs-wmissing-prototypes' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/josh/linux-misc * 'hostprogs-wmissing-prototypes' of git://git.kernel.org/pub/scm/linux/kernel/git/josh/linux-misc: Makefile: Add -Wmising-prototypes to HOSTCFLAGS oss: Mark loadhex static in hex2hex.c dtc: Mark various internal functions static dtc: Set "noinput" in the lexer to avoid an unused function drm: radeon: Mark several functions static in mkregtable arch/sparc/boot/*.c: Mark various internal functions static arch/powerpc/boot/addRamDisk.c: Mark several internal functions static arch/alpha/boot/tools/objstrip.c: Mark "usage" static Documentation/vm/page-types.c: Declare checked_open static genksyms: Mark is_reserved_word static kconfig: Mark various internal functions static kconfig: Make zconf.y work with current bison
2009-11-15Documentation/vm/page-types.c: Declare checked_open staticJosh Triplett1-1/+1
Nothing outside of Documentation/vm/page-types.c references checked_open. Signed-off-by: Josh Triplett <josh@joshtriplett.org>
2009-10-29Merge branch 'hwpoison-2.6.32' of ↵Linus Torvalds1-0/+136
git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6 * 'hwpoison-2.6.32' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6: HWPOISON: fix invalid page count in printk output HWPOISON: Allow schedule_on_each_cpu() from keventd HWPOISON: fix/proc/meminfo alignment HWPOISON: fix oops on ksm pages HWPOISON: Fix page count leak in hwpoison late kill in do_swap_page HWPOISON: return early on non-LRU pages HWPOISON: Add brief hwpoison description to Documentation HWPOISON: Clean up PR_MCE_KILL interface
2009-10-08page-types: add hwpoison/unpoison featureWu Fengguang1-1/+72
For hwpoison stress testing. The debugfs mount point is assumed to be /debug/. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-08page-types: introduce kpageflags_flags()Wu Fengguang1-4/+11
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-08page-types: make voffset local variablesWu Fengguang1-18/+21
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-08page-types: make standalone pagemap/kpageflags read routinesWu Fengguang1-65/+89
Refactor the code to be more modular and easier to reuse. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-08page-types: introduce checked_open()Wu Fengguang1-10/+14
This helps merge duplicate code (now and future) and outstand the main logic. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-08page-types: add GPL noteWu Fengguang1-1/+4
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-08pagemap: document KPF_KSM and show it in page-typesWu Fengguang2-0/+6
It indicates to the system admin that processes mapping such pages may be eating less physical memory than the reported numbers by legacy tools. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: Izik Eidus <ieidus@redhat.com> Acked-by: Chris Wright <chrisw@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-08pagemap: export KPF_HWPOISONWu Fengguang2-0/+6
This flag indicates a hardware detected memory corruption on the page. Any future access of the page data may bring down the machine. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-08ksm: more on default valuesHugh Dickins1-6/+7
Adjust the max_kernel_pages default to a quarter of totalram_pages, instead of nr_free_buffer_pages() / 4: the KSM pages themselves come from highmem, and even on a 16GB PAE machine, 4GB of KSM pages would only be pinning 32MB of lowmem with their rmap_items, so no need for the more obscure calculation (nor for its own special init function). There is no way for the user to switch KSM on if CONFIG_SYSFS is not enabled, so in that case default run to KSM_RUN_MERGE. Update KSM Documentation and Kconfig to reflect the new defaults. Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: Izik Eidus <ieidus@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-04HWPOISON: Add brief hwpoison description to DocumentationAndi Kleen1-0/+136
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-09-24Merge branch 'for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: truncate: use new helpers truncate: new helpers fs: fix overflow in sys_mount() for in-kernel calls fs: Make unload_nls() NULL pointer safe freeze_bdev: grab active reference to frozen superblocks freeze_bdev: kill bd_mount_sem exofs: remove BKL from super operations fs/romfs: correct error-handling code vfs: seq_file: add helpers for data filling vfs: remove redundant position check in do_sendfile vfs: change sb->s_maxbytes to a loff_t vfs: explicitly cast s_maxbytes in fiemap_check_ranges libfs: return error code on failed attr set seq_file: return a negative error code when seq_path_root() fails. vfs: optimize touch_time() too vfs: optimization for touch_atime() vfs: split generic_forget_inode() so that hugetlbfs does not have to copy it fs/inode.c: add dev-id and inode number for debugging in init_special_inode() libfs: make simple_read_from_buffer conventional
2009-09-24page-types: add feature for walking process address spaceWu Fengguang1-20/+180
Introduce "-p|--pid <pid>" for walking the process address space. The default action is to walk raw memory PFNs. Both the virtual address and physical address of each present pages will be listed: # ./tools/vm/page-types -lp $$ | head -3 voffset offset len flags 400 11bebe 1 __RU_lA____M______________________ 402 11bebc 1 __RU_lA____M______________________ Note that voffset/offset/len are now showed as hex numbers. [akpm@linux-foundation.org: coding-style fixes] Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-24Documentation/vm/.gitignore: add page-typesJosh Triplett1-0/+1
Signed-off-by: Josh Triplett <josh@joshtriplett.org> 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>
2009-09-24truncate: new helpersnpiggin@suse.de1-1/+1
Introduce new truncate helpers truncate_pagecache and inode_newsize_ok. vmtruncate is also consolidated from mm/memory.c and mm/nommu.c and into mm/truncate.c. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-09-23Documentation/: fix warnings from -Wmissing-prototypes in HOSTCFLAGSLadinu Chandrasinghe2-60/+60
Fix up -Wmissing-prototypes in compileable userspace code, mainly under Documentation/. Signed-off-by: Ladinu Chandrasinghe <ladinu.pub@gmail.com> Signed-off-by: Trevor Keith <tsrk@tsrk.net> Cc: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22hugetlb: add MAP_HUGETLB exampleEric B Munson3-6/+87
Add an example of how to use the MAP_HUGETLB flag to the vm documentation directory and a reference to the example in hugetlbpage.txt. Signed-off-by: Eric B Munson <ebmunson@us.ibm.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Adam Litke <agl@us.ibm.com> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22ksm: add some documentationHugh Dickins2-0/+91
Add Documentation/vm/ksm.txt: how to use the Kernel Samepage Merging feature Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: Michael Kerrisk <mtk.manpages@googlemail.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Acked-by: Izik Eidus <ieidus@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22hugetlb: clean up and update huge pages documentationLee Schermerhorn1-46/+87
Attempt to clarify huge page administration and usage, and updates the doucmentation to mention the balancing of huge pages across nodes when allocating and freeing. Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Nishanth Aravamudan <nacc@us.ibm.com> Cc: David Rientjes <rientjes@google.com> Cc: Adam Litke <agl@us.ibm.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: Eric Whitney <eric.whitney@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-10slub: add option to disable higher order debugging slabsDavid Rientjes1-0/+10
When debugging is enabled, slub requires that additional metadata be stored in slabs for certain options: SLAB_RED_ZONE, SLAB_POISON, and SLAB_STORE_USER. Consequently, it may require that the minimum possible slab order needed to allocate a single object be greater when using these options. The most notable example is for objects that are PAGE_SIZE bytes in size. Higher minimum slab orders may cause page allocation failures when oom or under heavy fragmentation. This patch adds a new slub_debug option, which disables debugging by default for caches that would have resulted in higher minimum orders: slub_debug=O When this option is used on systems with 4K pages, kmalloc-4096, for example, will not have debugging enabled by default even if CONFIG_SLUB_DEBUG_ON is defined because it would have resulted in a order-1 minimum slab order. Reported-by: Larry Finger <Larry.Finger@lwfinger.net> Tested-by: Larry Finger <Larry.Finger@lwfinger.net> Cc: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2009-06-17Documentation/vm/Makefile: don't try to build slqbinfoAndrew Morton1-1/+1
For it is only in linux-next at this stage. Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Matt Mackall <mpm@selenic.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16pagemap: add page-types toolWu Fengguang2-1/+699
Add page-types, a handy tool for querying page flags. It will expand some of the overloaded flags: PG_slob_free = PG_private PG_slub_frozen = PG_active PG_slub_debug = PG_error PG_readahead = PG_reclaim and mask out obscure flags except in -raw mode: PG_reserved PG_mlocked PG_mappedtodisk PG_private PG_private_2 PG_owner_priv_1 PG_arch_1 PG_uncached PG_compound* for non hugeTLB pages [akpm@linux-foundation.org: fix warning] Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Matt Mackall <mpm@selenic.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16pagemap: document 9 more exported page flagsWu Fengguang1-0/+62
Also add short descriptions for all of the 20 exported page flags. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Matt Mackall <mpm@selenic.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16pagemap: document clarificationsWu Fengguang1-3/+3
Some bit ranges were inclusive and some not. Fix them to be consistently inclusive. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Matt Mackall <mpm@selenic.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>