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The seq_buf functions are rather useful outside of tracing. Instead
of having it be dependent on CONFIG_TRACING, move the code into lib/
and allow other users to have access to it even when tracing is not
configured.
The seq_buf utility is similar to the seq_file utility, but instead of
writing sending data back up to userland, it writes it into a buffer
defined at seq_buf_init(). This allows us to send a descriptor around
that writes printf() formatted strings into it that can be retrieved
later.
It is currently used by the tracing facility for such things like trace
events to convert its binary saved data in the ring buffer into an
ASCII human readable context to be displayed in /sys/kernel/debug/trace.
It can also be used for doing NMI prints safely from NMI context into
the seq_buf and retrieved later and dumped to printk() safely. Doing
printk() from an NMI context is dangerous because an NMI can preempt
a current printk() and deadlock on it.
Link: http://lkml.kernel.org/p/20140619213952.058255809@goodmis.org
Tested-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tomba/linux
Pull fbdev updates from Tomi Valkeinen:
- new 6x10 font
- various small fixes and cleanups
* tag 'fbdev-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tomba/linux: (30 commits)
fonts: Add 6x10 font
videomode: provide dummy inline functions for !CONFIG_OF
video/atmel_lcdfb: Introduce regulator support
fbdev: sh_mobile_hdmi: Re-init regs before irq re-enable on resume
framebuffer: fix screen corruption when copying
framebuffer: fix border color
arm, fbdev, omap2, LLVMLinux: Remove nested function from omapfb
arm, fbdev, omap2, LLVMLinux: Remove nested function from omap2 dss
video: fbdev: valkyriefb.c: use container_of to resolve fb_info_valkyrie from fb_info
video: fbdev: pxafb.c: use container_of to resolve pxafb_info/layer from fb_info
video: fbdev: cyber2000fb.c: use container_of to resolve cfb_info from fb_info
video: fbdev: controlfb.c: use container_of to resolve fb_info_control from fb_info
video: fbdev: sa1100fb.c: use container_of to resolve sa1100fb_info from fb_info
video: fbdev: stifb.c: use container_of to resolve stifb_info from fb_info
video: fbdev: sis: sis_main.c: Cleaning up missing null-terminate in conjunction with strncpy
video: valkyriefb: Fix unused variable warning in set_valkyrie_clock()
video: fbdev: use %*ph specifier to dump small buffers
video: mx3fb: always enable BACKLIGHT_LCD_SUPPORT
video: fbdev: au1200fb: delete double assignment
video: fbdev: sis: delete double assignment
...
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Pull md updates from Neil Brown:
- a few minor bug fixes
- quite a lot of code tidy-up and simplification
- remove PRINT_RAID_DEBUG ioctl. I'm fairly sure it is unused, and it
isn't particularly useful.
* tag 'md/3.18' of git://neil.brown.name/md: (21 commits)
lib/raid6: Add log level to printks
md: move EXPORT_SYMBOL to after function in md.c
md: discard PRINT_RAID_DEBUG ioctl
md: remove MD_BUG()
md: clean up 'exit' labels in md_ioctl().
md: remove unnecessary test for MD_MAJOR in md_ioctl()
md: don't allow "-sync" to be set for device in an active array.
md: remove unwanted white space from md.c
md: don't start resync thread directly from md thread.
md: Just use RCU when checking for overlap between arrays.
md: avoid potential long delay under pers_lock
md: simplify export_array()
md: discard find_rdev_nr in favour of find_rdev_nr_rcu
md: use wait_event() to simplify md_super_wait()
md: be more relaxed about stopping an array which isn't started.
md/raid1: process_checks doesn't use its return value.
md/raid5: fix init_stripe() inconsistencies
md/raid10: another memory leak due to reshape.
md: use set_bit/clear_bit instead of shift/mask for bi_flags changes.
md/raid1: minor typos and reformatting.
...
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Replaced the use of a Variable Length Array In Struct (VLAIS) with a C99
compliant equivalent. This patch allocates the appropriate amount of memory
using a char array using the SHASH_DESC_ON_STACK macro.
The new code can be compiled with both gcc and clang.
Signed-off-by: Jan-Simon Möller <dl9pf@gmx.de>
Signed-off-by: Behan Webster <behanw@converseincode.com>
Reviewed-by: Mark Charlebois <charlebm@gmail.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Cc: pageexec@freemail.hu
Cc: "David S. Miller" <davem@davemloft.net>
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Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: NeilBrown <neilb@suse.de>
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This allows user to print a given buffer as an escaped string. The
rules are applied according to an optional mix of flags provided by
additional format letters.
For example, if the given buffer is:
1b 62 20 5c 43 07 22 90 0d 5d
The result strings would be:
%*pE "\eb \C\a"\220\r]"
%*pEhp "\x1bb \C\x07"\x90\x0d]"
%*pEa "\e\142\040\\\103\a\042\220\r\135"
Please, read Documentation/printk-formats.txt and lib/string_helpers.c
kernel documentation to get further information.
[akpm@linux-foundation.org: tidy up comment layout, per Joe]
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Suggested-by: Joe Perches <joe@perches.com>
Cc: "John W . Linville" <linville@tuxdriver.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This is almost the opposite function to string_unescape(). Nevertheless
it handles \0 and could be used for any byte buffer.
The documentation is supplied together with the function prototype.
The test cases covers most of the scenarios and would be expanded later
on.
[akpm@linux-foundation.org: avoid 1k stack consumption]
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: "John W . Linville" <linville@tuxdriver.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Joe Perches <joe@perches.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>
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This patch prepares test suite for a following update. It introduces
test_string_check_buf() helper which checks the result and dumps an error.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: "John W . Linville" <linville@tuxdriver.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The introduced function string_escape_mem() is a kind of opposite to
string_unescape. We have several users of such functionality each of
them created custom implementation. The series contains clean up of
test suite, adding new call, and switching few users to use it via %*pE
specifier.
Test suite covers all of existing and most of potential use cases.
This patch (of 11):
The documentation of API belongs to c-file. This patch moves it
accordingly.
There is no functional change.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: "John W . Linville" <linville@tuxdriver.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The previous patch made strnicmp into a wrapper for strncasecmp.
This patch makes all in-tree users of strnicmp call strncasecmp
directly, while still making sure that the strnicmp symbol can be used
by out-of-tree modules. It should be considered a temporary hack until
all in-tree callers have been converted.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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lib/string.c contains two functions, strnicmp and strncasecmp, which do
roughly the same thing, namely compare two strings case-insensitively up
to a given bound. They have slightly different implementations, but the
only important difference is that strncasecmp doesn't handle len==0
appropriately; it effectively becomes strcasecmp in that case. strnicmp
correctly says that two strings are always equal in their first 0
characters.
strncasecmp is the POSIX name for this functionality. So rename the
non-broken function to the standard name. To minimize the impact on the
rest of the kernel (and since both are exported to modules), make strnicmp
a wrapper for strncasecmp.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "H. Peter Anvin" <hpa@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The "_MODULE" suffix is reserved for tristates compiled as loadable kernel
modules (LKM). The "TEST_MODULE" feature thereby violates this
convention. The feature is used to compile the lib/test_module.c kernel
module.
Sadly this convention is not made explicit, but the Kconfig code documents
it. The following code (./scripts/kconfig/confdata.c) is used to generate
the autoconf.h header file during the build process. When a feature is
selected as a kernel module ('m'), it is suffixed with "_MODULE" to
indicate it.
switch (*value) {
case 'n':
break;
case 'm':
suffix = "_MODULE";
/* fall through */
This causes problems for static code analysis, which assumes a consistent
use of the "_MODULE" suffix.
This patch renames the feature and its reference in a Makefile to
"TEST_LKM", which still expresses the test of a LKM.
Signed-off-by: Valentin Rothberg <valentinrothberg@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The prio_heap code is unused since commit 889ed9ceaa97 ("cgroup: remove
css_scan_tasks()"). It should be compiled out to shrink the binary
kernel size which can be done via introducing CONFIG_PRIO_HEAD or by
removing the code.
We can simply recover the code from git when needed, so it would be
better to remove it IMO.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Francesco Fusco <ffusco@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: George Spelvin <linux@horizon.com>
Cc: Mark Salter <msalter@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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There is no textsearch_put(). Remove it from the comments to avoid
misunderstanding. Textsearch prepare no longer needs textsearch_put().
Signed-off-by: Raphael Silva <rapphil@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Using seq_open_private() removes boilerplate code from ddebug_proc_open().
The resultant code is shorter and easier to follow.
This patch does not change any functionality.
Signed-off-by: Rob Jones <rob.jones@codethink.co.uk>
Acked-by: Jason Baron <jbaron@akamai.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
"The main changes in this cycle were:
- Optimized support for Intel "Cluster-on-Die" (CoD) topologies (Dave
Hansen)
- Various sched/idle refinements for better idle handling (Nicolas
Pitre, Daniel Lezcano, Chuansheng Liu, Vincent Guittot)
- sched/numa updates and optimizations (Rik van Riel)
- sysbench speedup (Vincent Guittot)
- capacity calculation cleanups/refactoring (Vincent Guittot)
- Various cleanups to thread group iteration (Oleg Nesterov)
- Double-rq-lock removal optimization and various refactorings
(Kirill Tkhai)
- various sched/deadline fixes
... and lots of other changes"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (72 commits)
sched/dl: Use dl_bw_of() under rcu_read_lock_sched()
sched/fair: Delete resched_cpu() from idle_balance()
sched, time: Fix build error with 64 bit cputime_t on 32 bit systems
sched: Improve sysbench performance by fixing spurious active migration
sched/x86: Fix up typo in topology detection
x86, sched: Add new topology for multi-NUMA-node CPUs
sched/rt: Use resched_curr() in task_tick_rt()
sched: Use rq->rd in sched_setaffinity() under RCU read lock
sched: cleanup: Rename 'out_unlock' to 'out_free_new_mask'
sched: Use dl_bw_of() under RCU read lock
sched/fair: Remove duplicate code from can_migrate_task()
sched, mips, ia64: Remove __ARCH_WANT_UNLOCKED_CTXSW
sched: print_rq(): Don't use tasklist_lock
sched: normalize_rt_tasks(): Don't use _irqsave for tasklist_lock, use task_rq_lock()
sched: Fix the task-group check in tg_has_rt_tasks()
sched/fair: Leverage the idle state info when choosing the "idlest" cpu
sched: Let the scheduler see CPU idle states
sched/deadline: Fix inter- exclusive cpusets migrations
sched/deadline: Clear dl_entity params when setscheduling to different class
sched/numa: Kill the wrong/dead TASK_DEAD check in task_numa_fault()
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core locking updates from Ingo Molnar:
"The main updates in this cycle were:
- mutex MCS refactoring finishing touches: improve comments, refactor
and clean up code, reduce debug data structure footprint, etc.
- qrwlock finishing touches: remove old code, self-test updates.
- small rwsem optimization
- various smaller fixes/cleanups"
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/lockdep: Revert qrwlock recusive stuff
locking/rwsem: Avoid double checking before try acquiring write lock
locking/rwsem: Move EXPORT_SYMBOL() lines to follow function definition
locking/rwlock, x86: Delete unused asm/rwlock.h and rwlock.S
locking/rwlock, x86: Clean up asm/spinlock*.h to remove old rwlock code
locking/semaphore: Resolve some shadow warnings
locking/selftest: Support queued rwlock
locking/lockdep: Restrict the use of recursive read_lock() with qrwlock
locking/spinlocks: Always evaluate the second argument of spin_lock_nested()
locking/Documentation: Update locking/mutex-design.txt disadvantages
locking/Documentation: Move locking related docs into Documentation/locking/
locking/mutexes: Use MUTEX_SPIN_ON_OWNER when appropriate
locking/mutexes: Refactor optimistic spinning code
locking/mcs: Remove obsolete comment
locking/mutexes: Document quick lock release when unlocking
locking/mutexes: Standardize arguments in lock/unlock slowpaths
locking: Remove deprecated smp_mb__() barriers
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull arch atomic cleanups from Ingo Molnar:
"This is a series kept separate from the main locking tree, which
cleans up and improves various details in the atomics type handling:
- Remove the unused atomic_or_long() method
- Consolidate and compress atomic ops implementations between
architectures, to reduce linecount and to make it easier to add new
ops.
- Rewrite generic atomic support to only require cmpxchg() from an
architecture - generate all other methods from that"
* 'locking-arch-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
locking,arch: Use ACCESS_ONCE() instead of cast to volatile in atomic_read()
locking, mips: Fix atomics
locking, sparc64: Fix atomics
locking,arch: Rewrite generic atomic support
locking,arch,xtensa: Fold atomic_ops
locking,arch,sparc: Fold atomic_ops
locking,arch,sh: Fold atomic_ops
locking,arch,powerpc: Fold atomic_ops
locking,arch,parisc: Fold atomic_ops
locking,arch,mn10300: Fold atomic_ops
locking,arch,mips: Fold atomic_ops
locking,arch,metag: Fold atomic_ops
locking,arch,m68k: Fold atomic_ops
locking,arch,m32r: Fold atomic_ops
locking,arch,ia64: Fold atomic_ops
locking,arch,hexagon: Fold atomic_ops
locking,arch,cris: Fold atomic_ops
locking,arch,avr32: Fold atomic_ops
locking,arch,arm64: Fold atomic_ops
locking,arch,arm: Fold atomic_ops
...
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git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris.
Mostly ima, selinux, smack and key handling updates.
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (65 commits)
integrity: do zero padding of the key id
KEYS: output last portion of fingerprint in /proc/keys
KEYS: strip 'id:' from ca_keyid
KEYS: use swapped SKID for performing partial matching
KEYS: Restore partial ID matching functionality for asymmetric keys
X.509: If available, use the raw subjKeyId to form the key description
KEYS: handle error code encoded in pointer
selinux: normalize audit log formatting
selinux: cleanup error reporting in selinux_nlmsg_perm()
KEYS: Check hex2bin()'s return when generating an asymmetric key ID
ima: detect violations for mmaped files
ima: fix race condition on ima_rdwr_violation_check and process_measurement
ima: added ima_policy_flag variable
ima: return an error code from ima_add_boot_aggregate()
ima: provide 'ima_appraise=log' kernel option
ima: move keyring initialization to ima_init()
PKCS#7: Handle PKCS#7 messages that contain no X.509 certs
PKCS#7: Better handling of unsupported crypto
KEYS: Overhaul key identification when searching for asymmetric keys
KEYS: Implement binary asymmetric key ID handling
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
Pull percpu updates from Tejun Heo:
"A lot of activities on percpu front. Notable changes are...
- percpu allocator now can take @gfp. If @gfp doesn't contain
GFP_KERNEL, it tries to allocate from what's already available to
the allocator and a work item tries to keep the reserve around
certain level so that these atomic allocations usually succeed.
This will replace the ad-hoc percpu memory pool used by
blk-throttle and also be used by the planned blkcg support for
writeback IOs.
Please note that I noticed a bug in how @gfp is interpreted while
preparing this pull request and applied the fix 6ae833c7fe0c
("percpu: fix how @gfp is interpreted by the percpu allocator")
just now.
- percpu_ref now uses longs for percpu and global counters instead of
ints. It leads to more sparse packing of the percpu counters on
64bit machines but the overhead should be negligible and this
allows using percpu_ref for refcnting pages and in-memory objects
directly.
- The switching between percpu and single counter modes of a
percpu_ref is made independent of putting the base ref and a
percpu_ref can now optionally be initialized in single or killed
mode. This allows avoiding percpu shutdown latency for cases where
the refcounted objects may be synchronously created and destroyed
in rapid succession with only a fraction of them reaching fully
operational status (SCSI probing does this when combined with
blk-mq support). It's also planned to be used to implement forced
single mode to detect underflow more timely for debugging.
There's a separate branch percpu/for-3.18-consistent-ops which cleans
up the duplicate percpu accessors. That branch causes a number of
conflicts with s390 and other trees. I'll send a separate pull
request w/ resolutions once other branches are merged"
* 'for-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (33 commits)
percpu: fix how @gfp is interpreted by the percpu allocator
blk-mq, percpu_ref: start q->mq_usage_counter in atomic mode
percpu_ref: make INIT_ATOMIC and switch_to_atomic() sticky
percpu_ref: add PERCPU_REF_INIT_* flags
percpu_ref: decouple switching to percpu mode and reinit
percpu_ref: decouple switching to atomic mode and killing
percpu_ref: add PCPU_REF_DEAD
percpu_ref: rename things to prepare for decoupling percpu/atomic mode switch
percpu_ref: replace pcpu_ prefix with percpu_
percpu_ref: minor code and comment updates
percpu_ref: relocate percpu_ref_reinit()
Revert "blk-mq, percpu_ref: implement a kludge for SCSI blk-mq stall during probe"
Revert "percpu: free percpu allocation info for uniprocessor system"
percpu-refcount: make percpu_ref based on longs instead of ints
percpu-refcount: improve WARN messages
percpu: fix locking regression in the failure path of pcpu_alloc()
percpu-refcount: add @gfp to percpu_ref_init()
proportions: add @gfp to init functions
percpu_counter: add @gfp to percpu_counter_init()
percpu_counter: make percpu_counters_lock irq-safe
...
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After allocating an address from a particular genpool, there is no good
way to verify if that address actually belongs to a genpool. Introduce
addr_in_gen_pool which will return if an address plus size falls
completely within the genpool range.
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Olof Johansson <olof@lixom.net>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Riley <davidriley@chromium.org>
Cc: Ritesh Harjain <ritesh.harjani@gmail.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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One of the more common algorithms used for allocation is to align the
start address of the allocation to the order of size requested. Add this
as an algorithm option for genalloc.
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Olof Johansson <olof@lixom.net>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Riley <davidriley@chromium.org>
Cc: Ritesh Harjain <ritesh.harjani@gmail.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This font is suitable for framebuffer consoles on devices with a
320x240 screen, to get a reasonable number of characters (53x24) that
are still at a readable size.
The font is derived from the existing 6x11 font, but gets 3 extra
lines without sacrificing readability. Also I redesigned a some glyhps
so they are more distinct and better fill the available space.
Signed-off-by: Maarten ter Huurne <maarten@treewalker.org>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
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Pull networking updates from David Miller:
"Most notable changes in here:
1) By far the biggest accomplishment, thanks to a large range of
contributors, is the addition of multi-send for transmit. This is
the result of discussions back in Chicago, and the hard work of
several individuals.
Now, when the ->ndo_start_xmit() method of a driver sees
skb->xmit_more as true, it can choose to defer the doorbell
telling the driver to start processing the new TX queue entires.
skb->xmit_more means that the generic networking is guaranteed to
call the driver immediately with another SKB to send.
There is logic added to the qdisc layer to dequeue multiple
packets at a time, and the handling mis-predicted offloads in
software is now done with no locks held.
Finally, pktgen is extended to have a "burst" parameter that can
be used to test a multi-send implementation.
Several drivers have xmit_more support: i40e, igb, ixgbe, mlx4,
virtio_net
Adding support is almost trivial, so export more drivers to
support this optimization soon.
I want to thank, in no particular or implied order, Jesper
Dangaard Brouer, Eric Dumazet, Alexander Duyck, Tom Herbert, Jamal
Hadi Salim, John Fastabend, Florian Westphal, Daniel Borkmann,
David Tat, Hannes Frederic Sowa, and Rusty Russell.
2) PTP and timestamping support in bnx2x, from Michal Kalderon.
3) Allow adjusting the rx_copybreak threshold for a driver via
ethtool, and add rx_copybreak support to enic driver. From
Govindarajulu Varadarajan.
4) Significant enhancements to the generic PHY layer and the bcm7xxx
driver in particular (EEE support, auto power down, etc.) from
Florian Fainelli.
5) Allow raw buffers to be used for flow dissection, allowing drivers
to determine the optimal "linear pull" size for devices that DMA
into pools of pages. The objective is to get exactly the
necessary amount of headers into the linear SKB area pre-pulled,
but no more. The new interface drivers use is eth_get_headlen().
From WANG Cong, with driver conversions (several had their own
by-hand duplicated implementations) by Alexander Duyck and Eric
Dumazet.
6) Support checksumming more smoothly and efficiently for
encapsulations, and add "foo over UDP" facility. From Tom
Herbert.
7) Add Broadcom SF2 switch driver to DSA layer, from Florian
Fainelli.
8) eBPF now can load programs via a system call and has an extensive
testsuite. Alexei Starovoitov and Daniel Borkmann.
9) Major overhaul of the packet scheduler to use RCU in several major
areas such as the classifiers and rate estimators. From John
Fastabend.
10) Add driver for Intel FM10000 Ethernet Switch, from Alexander
Duyck.
11) Rearrange TCP_SKB_CB() to reduce cache line misses, from Eric
Dumazet.
12) Add Datacenter TCP congestion control algorithm support, From
Florian Westphal.
13) Reorganize sk_buff so that __copy_skb_header() is significantly
faster. From Eric Dumazet"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1558 commits)
netlabel: directly return netlbl_unlabel_genl_init()
net: add netdev_txq_bql_{enqueue, complete}_prefetchw() helpers
net: description of dma_cookie cause make xmldocs warning
cxgb4: clean up a type issue
cxgb4: potential shift wrapping bug
i40e: skb->xmit_more support
net: fs_enet: Add NAPI TX
net: fs_enet: Remove non NAPI RX
r8169:add support for RTL8168EP
net_sched: copy exts->type in tcf_exts_change()
wimax: convert printk to pr_foo()
af_unix: remove 0 assignment on static
ipv6: Do not warn for informational ICMP messages, regardless of type.
Update Intel Ethernet Driver maintainers list
bridge: Save frag_max_size between PRE_ROUTING and POST_ROUTING
tipc: fix bug in multicast congestion handling
net: better IFF_XMIT_DST_RELEASE support
net/mlx4_en: remove NETDEV_TX_BUSY
3c59x: fix bad split of cpu_to_le32(pci_map_single())
net: bcmgenet: fix Tx ring priority programming
...
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull compression update from Greg KH:
"More fun with the LZO compression code. Here's some patches that
properly document what the logic is, and fix up all of the previously
reported issues against the LZO code.
This has been in linux-next for a while with no issues"
* tag 'compress-3.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
lzo: check for length overrun in variable length encoding.
Revert "lzo: properly check for overruns"
Documentation: lzo: document part of the encoding
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core update from Greg KH:
"Here's the driver core patches for 3.18-rc1. Just a few small things,
and the addition of a new interface to dump firmware "core dumps" to
userspace through sysfs that the wireless and graphic drivers want to
use.
All of these have been in linux-next for a while"
* tag 'driver-core-3.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
dynamic_debug: change __dynamic_<foo>_dbg return types to void
driver/base/node: remove unnecessary kfree of node struct from unregister_one_node
devres: Improve devm_kasprintf()/kvasprintf() support
Documentation: devres: Add missing devm_kstrdup() managed interface
Documentation: devres: Add missing IRQ functions
firmware_class: make sure fw requests contain a name
driver core: Remove kerneldoc from local function
attribute_container: fix coding style issues
attribute_container: fix whitespace errors
drivers/base: Fix length checks in create_syslog_header()/dev_vprintk_emit()
device coredump: add new device coredump class
Documentation/sysfs-rules.txt: Add device attribute error code documentation
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git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull "trivial tree" updates from Jiri Kosina:
"Usual pile from trivial tree everyone is so eagerly waiting for"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
Remove MN10300_PROC_MN2WS0038
mei: fix comments
treewide: Fix typos in Kconfig
kprobes: update jprobe_example.c for do_fork() change
Documentation: change "&" to "and" in Documentation/applying-patches.txt
Documentation: remove obsolete pcmcia-cs from Changes
Documentation: update links in Changes
Documentation: Docbook: Fix generated DocBook/kernel-api.xml
score: Remove GENERIC_HAS_IOMAP
gpio: fix 'CONFIG_GPIO_IRQCHIP' comments
tty: doc: Fix grammar in serial/tty
dma-debug: modify check_for_stack output
treewide: fix errors in printk
genirq: fix reference in devm_request_threaded_irq comment
treewide: fix synchronize_rcu() in comments
checkstack.pl: port to AArch64
doc: queue-sysfs: minor fixes
init/do_mounts: better syntax description
MIPS: fix comment spelling
powerpc/simpleboot: fix comment
...
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The return value is not used by callers of these functions
so change the functions to return void.
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Jason Baron <jbaron@akamai.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Commit f0bab73cb539 ("locking/lockdep: Restrict the use of recursive
read_lock() with qrwlock") changed lockdep to try and conform to the
qrwlock semantics which differ from the traditional rwlock semantics.
In particular qrwlock is fair outside of interrupt context, but in
interrupt context readers will ignore all fairness.
The problem modeling this is that read and write side have different
lock state (interrupts) semantics but we only have a single
representation of these. Therefore lockdep will get confused, thinking
the lock can cause interrupt lock inversions.
So revert it for now; the old rwlock semantics were already imperfectly
modeled and the qrwlock extra won't fit either.
If we want to properly fix this, I think we need to resurrect the work
by Gautham did a few years ago that split the read and write state of
locks:
http://lwn.net/Articles/332801/
FWIW the locking selftest that would've failed (and was reported by
Borislav earlier) is something like:
RL(X1); /* IRQ-ON */
LOCK(A);
UNLOCK(A);
RU(X1);
IRQ_ENTER();
RL(X1); /* IN-IRQ */
RU(X1);
IRQ_EXIT();
At which point it would report that because A is an IRQ-unsafe lock we
can suffer the following inversion:
CPU0 CPU1
lock(A)
lock(X1)
lock(A)
<IRQ>
lock(X1)
And this is 'wrong' because X1 can recurse (assuming the above lock are
in fact read-lock) but lockdep doesn't know about this.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Waiman Long <Waiman.Long@hp.com>
Cc: ego@linux.vnet.ibm.com
Cc: bp@alien8.de
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20140930132600.GA7444@worktop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Conflicts:
drivers/net/usb/r8152.c
net/netfilter/nfnetlink.c
Both r8152 and nfnetlink conflicts were simple overlapping changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
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Pull networking fixes from David Miller:
1) Don't halt the firmware in r8152 driver, from Hayes Wang.
2) Handle full sized 802.1ad frames in bnx2 and tg3 drivers properly,
from Vlad Yasevich.
3) Don't sleep while holding tx_clean_lock in netxen driver, fix from
Manish Chopra.
4) Certain kinds of ipv6 routes can end up endlessly failing the route
validation test, causing it to be re-looked up over and over again.
This particularly kills input route caching in TCP sockets. Fix
from Hannes Frederic Sowa.
5) netvsc_start_xmit() has a use-after-free access to skb->len, fix
from K Y Srinivasan.
6) Fix matching of inverted containers in ematch module, from Ignacy
Gawędzki.
7) Aggregation of GRO frames via SKB ->frag_list for linear skbs isn't
handled properly, regression fix from Eric Dumazet.
8) Don't test return value of ipv4_neigh_lookup(), which returns an
error pointer, against NULL. From WANG Cong.
9) Fix an old regression where we mistakenly allow a double add of the
same tunnel. Fixes from Steffen Klassert.
10) macvtap device delete and open can run in parallel and corrupt lists
etc., fix from Vlad Yasevich.
11) Fix build error with IPV6=m NETFILTER_XT_TARGET_TPROXY=y, from Pablo
Neira Ayuso.
12) rhashtable_destroy() triggers lockdep splats, fix also from Pablo.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (32 commits)
bna: Update Maintainer Email
r8152: disable power cut for RTL8153
r8152: remove clearing bp
bnx2: Correctly receive full sized 802.1ad fragmes
tg3: Allow for recieve of full-size 8021AD frames
r8152: fix setting RTL8152_UNPLUG
netxen: Fix bug in Tx completion path.
netxen: Fix BUG "sleeping function called from invalid context"
ipv6: remove rt6i_genid
hyperv: Fix a bug in netvsc_start_xmit()
net: stmmac: fix stmmac_pci_probe failed when CONFIG_HAVE_CLK is selected
ematch: Fix matching of inverted containers.
gro: fix aggregation for skb using frag_list
neigh: check error pointer instead of NULL for ipv4_neigh_lookup()
ip6_gre: Return an error when adding an existing tunnel.
ip6_vti: Return an error when adding an existing tunnel.
ip6_tunnel: Return an error when adding an existing tunnel.
ip6gre: add a rtnl link alias for ip6gretap
net/mlx4_core: Allow not to specify probe_vf in SRIOV IB mode
r8152: fix the carrier off when autoresuming
...
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This fix ensures that we never meet an integer overflow while adding
255 while parsing a variable length encoding. It works differently from
commit 206a81c ("lzo: properly check for overruns") because instead of
ensuring that we don't overrun the input, which is tricky to guarantee
due to many assumptions in the code, it simply checks that the cumulated
number of 255 read cannot overflow by bounding this number.
The MAX_255_COUNT is the maximum number of times we can add 255 to a base
count without overflowing an integer. The multiply will overflow when
multiplying 255 by more than MAXINT/255. The sum will overflow earlier
depending on the base count. Since the base count is taken from a u8
and a few bits, it is safe to assume that it will always be lower than
or equal to 2*255, thus we can always prevent any overflow by accepting
two less 255 steps.
This patch also reduces the CPU overhead and actually increases performance
by 1.1% compared to the initial code, while the previous fix costs 3.1%
(measured on x86_64).
The fix needs to be backported to all currently supported stable kernels.
Reported-by: Willem Pinckaers <willem@lekkertech.net>
Cc: "Don A. Bailey" <donb@securitymouse.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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This reverts commit 206a81c ("lzo: properly check for overruns").
As analysed by Willem Pinckaers, this fix is still incomplete on
certain rare corner cases, and it is easier to restart from the
original code.
Reported-by: Willem Pinckaers <willem@lekkertech.net>
Cc: "Don A. Bailey" <donb@securitymouse.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Pablo Neira Ayuso says:
====================
nf pull request for net
This series contains netfilter fixes for net, they are:
1) Fix lockdep splat in nft_hash when releasing sets from the
rcu_callback context. We don't the mutex there anymore.
2) Remove unnecessary spinlock_bh in the destroy path of the nf_tables
rbtree set type from rcu_callback context.
3) Fix another lockdep splat in rhashtable. None of the callers hold
a mutex when calling rhashtable_destroy.
4) Fix duplicated error reporting from nfnetlink when aborting and
replaying a batch.
5) Fix a Kconfig issue reported by kbuild robot.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
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1.
the library includes a trivial set of BPF syscall wrappers:
int bpf_create_map(int key_size, int value_size, int max_entries);
int bpf_update_elem(int fd, void *key, void *value);
int bpf_lookup_elem(int fd, void *key, void *value);
int bpf_delete_elem(int fd, void *key);
int bpf_get_next_key(int fd, void *key, void *next_key);
int bpf_prog_load(enum bpf_prog_type prog_type,
const struct sock_filter_int *insns, int insn_len,
const char *license);
bpf_prog_load() stores verifier log into global bpf_log_buf[] array
and BPF_*() macros to build instructions
2.
test stubs configure eBPF infra with 'unspec' map and program types.
These are fake types used by user space testsuite only.
3.
verifier tests valid and invalid programs and expects predefined
error log messages from kernel.
40 tests so far.
$ sudo ./test_verifier
#0 add+sub+mul OK
#1 unreachable OK
#2 unreachable2 OK
#3 out of range jump OK
#4 out of range jump2 OK
#5 test1 ld_imm64 OK
...
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Decrement the np_pool device_node refcount, which was incremented on
the preceding of_parse_phandle() call.
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Currently, a percpu_ref which is initialized with
PERPCU_REF_INIT_ATOMIC or switched to atomic mode via
switch_to_atomic() automatically reverts to percpu mode on the first
percpu_ref_reinit(). This makes the atomic mode difficult to use for
cases where a percpu_ref is used as a persistent on/off switch which
may be cycled multiple times.
This patch makes such atomic state sticky so that it survives through
kill/reinit cycles. After this patch, atomic state is cleared only by
an explicit percpu_ref_switch_to_percpu() call.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
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With the recent addition of percpu_ref_reinit(), percpu_ref now can be
used as a persistent switch which can be turned on and off repeatedly
where turning off maps to killing the ref and waiting for it to drain;
however, there currently isn't a way to initialize a percpu_ref in its
off (killed and drained) state, which can be inconvenient for certain
persistent switch use cases.
Similarly, percpu_ref_switch_to_atomic/percpu() allow dynamic
selection of operation mode; however, currently a newly initialized
percpu_ref is always in percpu mode making it impossible to avoid the
latency overhead of switching to atomic mode.
This patch adds @flags to percpu_ref_init() and implements the
following flags.
* PERCPU_REF_INIT_ATOMIC : start ref in atomic mode
* PERCPU_REF_INIT_DEAD : start ref killed and drained
These flags should be able to serve the above two use cases.
v2: target_core_tpg.c conversion was missing. Fixed.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
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percpu_ref has treated the dropping of the base reference and
switching to atomic mode as an integral operation; however, there's
nothing inherent tying the two together.
The use cases for percpu_ref have been expanding continuously. While
the current init/kill/reinit/exit model can cover a lot, the coupling
of kill/reinit with atomic/percpu mode switching is turning out to be
too restrictive for use cases where many percpu_refs are created and
destroyed back-to-back with only some of them reaching extended
operation. The coupling also makes implementing always-atomic debug
mode difficult.
This patch separates out percpu mode switching into
percpu_ref_switch_to_percpu() and reimplements percpu_ref_reinit() on
top of it.
* DEAD still requires ATOMIC. A dead ref can't be switched to percpu
mode w/o going through reinit.
v2: __percpu_ref_switch_to_percpu() was missing static. Fixed.
Reported by Fengguang aka kbuild test robot.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: kbuild test robot <fengguang.wu@intel.com>
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percpu_ref has treated the dropping of the base reference and
switching to atomic mode as an integral operation; however, there's
nothing inherent tying the two together.
The use cases for percpu_ref have been expanding continuously. While
the current init/kill/reinit/exit model can cover a lot, the coupling
of kill/reinit with atomic/percpu mode switching is turning out to be
too restrictive for use cases where many percpu_refs are created and
destroyed back-to-back with only some of them reaching extended
operation. The coupling also makes implementing always-atomic debug
mode difficult.
This patch separates out atomic mode switching into
percpu_ref_switch_to_atomic() and reimplements
percpu_ref_kill_and_confirm() on top of it.
* The handling of __PERCPU_REF_ATOMIC and __PERCPU_REF_DEAD is now
differentiated. Among get/put operations, percpu_ref_tryget_live()
is the only one which cares about DEAD.
* percpu_ref_switch_to_atomic() can be called multiple times on the
same ref. This means that multiple @confirm_switch may get queued
up which we can't do reliably without extra memory area. This is
handled by making the later invocation synchronously wait for the
completion of the previous one. This isn't particularly desirable
but such synchronous waits shouldn't happen in most cases.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
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percpu_ref will be restructured so that percpu/atomic mode switching
and reference killing are dedoupled. In preparation, add
PCPU_REF_DEAD and PCPU_REF_ATOMIC_DEAD which is OR of ATOMIC and DEAD.
For now, ATOMIC and DEAD are changed together and all PCPU_REF_ATOMIC
uses are converted to PCPU_REF_ATOMIC_DEAD without causing any
behavior changes.
percpu_ref_init() now specifies an explicit alignment when allocating
the percpu counters so that the pointer has enough unused low bits to
accomodate the flags. Note that one flag was fine as min alignment
for percpu memory is 2 bytes but two flags are already too many for
the natural alignment of unsigned longs on archs like cris and m68k.
v2: The original patch had BUILD_BUG_ON() which triggers if unsigned
long's alignment isn't enough to accomodate the flags, which
triggered on cris and m64k. percpu_ref_init() updated to specify
the required alignment explicitly. Reported by Fengguang.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Kent Overstreet <kmo@daterainc.com>
Cc: kbuild test robot <fengguang.wu@intel.com>
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percpu_ref will be restructured so that percpu/atomic mode switching
and reference killing are dedoupled. In preparation, do the following
renames.
* percpu_ref->confirm_kill -> percpu_ref->confirm_switch
* __PERCPU_REF_DEAD -> __PERCPU_REF_ATOMIC
* __percpu_ref_alive() -> __ref_is_percpu()
This patch is pure rename and doesn't introduce any functional
changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Kent Overstreet <kmo@daterainc.com>
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percpu_ref uses pcpu_ prefix for internal stuff and percpu_ for
externally visible ones. This is the same convention used in the
percpu allocator implementation. It works fine there but percpu_ref
doesn't have too much internal-only stuff and scattered usages of
pcpu_ prefix are confusing than helpful.
This patch replaces all pcpu_ prefixes with percpu_. This is pure
rename and there's no functional change. Note that PCPU_REF_DEAD is
renamed to __PERCPU_REF_DEAD to signify that the flag is internal.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Kent Overstreet <kmo@daterainc.com>
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* Some comments became stale. Updated.
* percpu_ref_tryget() unnecessarily initializes @ret. Removed.
* A blank line removed from percpu_ref_kill_rcu().
* Explicit function name in a WARN format string replaced with __func__.
* WARN_ON() in percpu_ref_reinit() converted to WARN_ON_ONCE().
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Kent Overstreet <kmo@daterainc.com>
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percpu_ref is gonna go through restructuring. Move
percpu_ref_reinit() after percpu_ref_kill_and_confirm(). This will
make later changes easier to follow and result in cleaner
organization.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Kent Overstreet <kmo@daterainc.com>
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probe"
This reverts commit 0a30288da1aec914e158c2d7a3482a85f632750f, which
was a temporary fix for SCSI blk-mq stall issue. The following
patches will fix the issue properly by introducing atomic mode to
percpu_ref.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>
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git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block into for-3.18
This is to receive 0a30288da1ae ("blk-mq, percpu_ref: implement a
kludge for SCSI blk-mq stall during probe") which implements
__percpu_ref_kill_expedited() to work around SCSI blk-mq stall. The
commit reverted and patches to implement proper fix will be added.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>
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blk-mq uses percpu_ref for its usage counter which tracks the number
of in-flight commands and used to synchronously drain the queue on
freeze. percpu_ref shutdown takes measureable wallclock time as it
involves a sched RCU grace period. This means that draining a blk-mq
takes measureable wallclock time. One would think that this shouldn't
matter as queue shutdown should be a rare event which takes place
asynchronously w.r.t. userland.
Unfortunately, SCSI probing involves synchronously setting up and then
tearing down a lot of request_queues back-to-back for non-existent
LUNs. This means that SCSI probing may take more than ten seconds
when scsi-mq is used.
This will be properly fixed by implementing a mechanism to keep
q->mq_usage_counter in atomic mode till genhd registration; however,
that involves rather big updates to percpu_ref which is difficult to
apply late in the devel cycle (v3.17-rc6 at the moment). As a
stop-gap measure till the proper fix can be implemented in the next
cycle, this patch introduces __percpu_ref_kill_expedited() and makes
blk_mq_freeze_queue() use it. This is heavy-handed but should work
for testing the experimental SCSI blk-mq implementation.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Christoph Hellwig <hch@infradead.org>
Link: http://lkml.kernel.org/g/20140919113815.GA10791@lst.de
Fixes: add703fda981 ("blk-mq: use percpu_ref for mq usage count")
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Tested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
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