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2010-11-30regulator: Staticise mc13783_powermisc_rmw()Mark Brown
It is not used outside this driver so no need to make the symbol global. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Alberto Panizzo <maramaopercheseimorto@gmail.com> Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
2010-11-30regulator: regulator disable supply fixMattias Wallin
This patch fixes a disable failure when regulator supply is used. A while loop in regulator disable checks for supply pointer != NULL but the pointer is not always updated, resulting in the while loop running too many times causing a disable failure. Signed-off-by: Mattias Wallin <mattias.wallin@stericsson.com> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
2010-11-30sched: Add 'autogroup' scheduling feature: automated per session task groupsMike Galbraith
A recurring complaint from CFS users is that parallel kbuild has a negative impact on desktop interactivity. This patch implements an idea from Linus, to automatically create task groups. Currently, only per session autogroups are implemented, but the patch leaves the way open for enhancement. Implementation: each task's signal struct contains an inherited pointer to a refcounted autogroup struct containing a task group pointer, the default for all tasks pointing to the init_task_group. When a task calls setsid(), a new task group is created, the process is moved into the new task group, and a reference to the preveious task group is dropped. Child processes inherit this task group thereafter, and increase it's refcount. When the last thread of a process exits, the process's reference is dropped, such that when the last process referencing an autogroup exits, the autogroup is destroyed. At runqueue selection time, IFF a task has no cgroup assignment, its current autogroup is used. Autogroup bandwidth is controllable via setting it's nice level through the proc filesystem: cat /proc/<pid>/autogroup Displays the task's group and the group's nice level. echo <nice level> > /proc/<pid>/autogroup Sets the task group's shares to the weight of nice <level> task. Setting nice level is rate limited for !admin users due to the abuse risk of task group locking. The feature is enabled from boot by default if CONFIG_SCHED_AUTOGROUP=y is selected, but can be disabled via the boot option noautogroup, and can also be turned on/off on the fly via: echo [01] > /proc/sys/kernel/sched_autogroup_enabled ... which will automatically move tasks to/from the root task group. Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Paul Turner <pjt@google.com> Cc: Oleg Nesterov <oleg@redhat.com> [ Removed the task_group_path() debug code, and fixed !EVENTFD build failure. ] Signed-off-by: Ingo Molnar <mingo@elte.hu> LKML-Reference: <1290281700.28711.9.camel@maggy.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-30ARM: 6505/1: kprobes: Don't HAVE_KPROBES when CONFIG_THUMB2_KERNEL is selectedDave Martin
Currently, the kprobes implementation for ARM only supports the ARM instruction set, so it only works if CONFIG_THUMB2_KERNEL is not enabled. Until kprobes is updated to work with Thumb-2, turning it on will cause horrible things to happen, so this patch disables it for now. Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-11-30ARM: 6508/1: vexpress: Correct data alignment in headsmp.S for ↵Dave Martin
CONFIG_THUMB2_KERNEL Directives such as .long and .word do not magically cause the assembler location counter to become aligned in gas. As a result, using these directives in code sections can result in misaligned data words when building a Thumb-2 kernel (CONFIG_THUMB2_KERNEL). This is a Bad Thing, since the ABI permits the compiler to assume that fundamental types of word size or above are word- aligned when accessing them from C. If the data is not really word-aligned, this can cause impaired performance and stray alignment faults in some circumstances. In general, the following rules should be applied when using data word declaration directives inside code sections: * .quad and .double: .align 3 * .long, .word, .single, .float: .align (or .align 2) * .short: No explicit alignment required, since Thumb-2 instructions are always 2 or 4 bytes in size. immediately after an instruction. Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-11-30ARM: 6507/1: RealView: Correct data alignment in headsmp.S for ↵Dave Martin
CONFIG_THUMB2_KERNEL Directives such as .long and .word do not magically cause the assembler location counter to become aligned in gas. As a result, using these directives in code sections can result in misaligned data words when building a Thumb-2 kernel (CONFIG_THUMB2_KERNEL). This is a Bad Thing, since the ABI permits the compiler to assume that fundamental types of word size or above are word- aligned when accessing them from C. If the data is not really word-aligned, this can cause impaired performance and stray alignment faults in some circumstances. In general, the following rules should be applied when using data word declaration directives inside code sections: * .quad and .double: .align 3 * .long, .word, .single, .float: .align (or .align 2) * .short: No explicit alignment required, since Thumb-2 instructions are always 2 or 4 bytes in size. immediately after an instruction. Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-11-30ARM: 6504/1: Thumb-2: Fix long-distance conditional branches in head.S for ↵Dave Martin
Thumb-2. The 32-bit conditional branches in Thumb-2 have a shorter range (+/-512K) than their ARM counterparts (+/-32MB). The linker does not currently generate trampolines to extend the range of these Thumb-2 conditional branches, resulting in link errors when vmlinux is sufficiently large, e.g.: head.o:(.text+0x464): relocation truncated to fit: R_ARM_THM_JUMP19 This patch forces the longer-range, unconditional branch encoding by use of an explicit IT instruction. The resulting branches are triggered on the same conditions as before. Signed-off-by: Dave Martin <dave.martin@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-11-30ARM: 6503/1: Thumb-2: Restore sensible zImage header layout for ↵Dave Martin
CONFIG_THUMB2_KERNEL The code which makes up the zImage header intends to leave a 32-byte gap followed by a branch to the real entry point, a magic number, and a word containing the absolute entry point address. This gets messed up with with CONFIG_THUMB2_KERNEL, because the size of the initial padding NOPs changes. Instead, the header can be made fully compatible by restoring it to ARM. In the Thumb-2 case, we can replace the initial NOPs with a sequence which switches to Thumb and jumps to the real entry point. As a consequence, the zImage entry point is now always ARM, so no special magic is needed any more for the uImage rules in the Thumb-2 case. Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-11-30ARM: 6502/1: Thumb-2: Fix CONFIG_THUMB2_KERNEL breakage in compressed/head.SDave Martin
Some instruction operand combinations are used here which are nor permitted in Thumb-2. In particular, most uses of pc as an operand are disallowed in Thumb-2, and deprecated in ARM from ARMv7 onwards. The modified code introduced by this patch should be compatible with all architecture versions >= v3, with or without CONFIG_THUMB2_KERNEL. Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-11-30ARM: 6501/1: Thumb-2: Correct data alignment for CONFIG_THUMB2_KERNEL in ↵Dave Martin
mm/proc-v7.S Directives such as .long and .word do not magically cause the assembler location counter to become aligned in gas. As a result, using these directives in code sections can result in misaligned data words when building a Thumb-2 kernel (CONFIG_THUMB2_KERNEL). This is a Bad Thing, since the ABI permits the compiler to assume that fundamental types of word size or above are word- aligned when accessing them from C. If the data is not really word-aligned, this can cause impaired performance and stray alignment faults in some circumstances. In general, the following rules should be applied when using data word declaration directives inside code sections: * .quad and .double: .align 3 * .long, .word, .single, .float: .align (or .align 2) * .short: No explicit alignment required, since Thumb-2 instructions are always 2 or 4 bytes in size. immediately after an instruction. In this specific case, we can achieve the desired alignment by forcing a 32-bit branch instruction using the W() macro, since the assembler location counter is already 32-bit aligned in this case. Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-11-30ARM: 6500/1: Thumb-2: Correct data alignment for CONFIG_THUMB2_KERNEL in ↵Dave Martin
kernel/head.S Directives such as .long and .word do not magically cause the assembler location counter to become aligned in gas. As a result, using these directives in code sections can result in misaligned data words when building a Thumb-2 kernel (CONFIG_THUMB2_KERNEL). This is a Bad Thing, since the ABI permits the compiler to assume that fundamental types of word size or above are word- aligned when accessing them from C. If the data is not really word-aligned, this can cause impaired performance and stray alignment faults in some circumstances. In general, the following rules should be applied when using data word declaration directives inside code sections: * .quad and .double: .align 3 * .long, .word, .single, .float: .align (or .align 2) * .short: No explicit alignment required, since Thumb-2 instructions are always 2 or 4 bytes in size. immediately after an instruction. Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-11-30ARM: 6499/1: Thumb-2: Correct data alignment for CONFIG_THUMB2_KERNEL in ↵Dave Martin
bootp/init.S Directives such as .long and .word do not magically cause the assembler location counter to become aligned in gas. As a result, using these directives in code sections can result in misaligned data words when building a Thumb-2 kernel (CONFIG_THUMB2_KERNEL). This is a Bad Thing, since the ABI permits the compiler to assume that fundamental types of word size or above are word- aligned when accessing them from C. If the data is not really word-aligned, this can cause impaired performance and stray alignment faults in some circumstances. In general, the following rules should be applied when using data word declaration directives inside code sections: * .quad and .double: .align 3 * .long, .word, .single, .float: .align (or .align 2) * .short: No explicit alignment required, since Thumb-2 instructions are always 2 or 4 bytes in size. immediately after an instruction. Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-11-30ARM: 6498/1: vfp: Correct data alignment for CONFIG_THUMB2_KERNELDave Martin
Directives such as .long and .word do not magically cause the assembler location counter to become aligned in gas. As a result, using these directives in code sections can result in misaligned data words when building a Thumb-2 kernel (CONFIG_THUMB2_KERNEL). This is a Bad Thing, since the ABI permits the compiler to assume that fundamental types of word size or above are word- aligned when accessing them from C. If the data is not really word-aligned, this can cause impaired performance and stray alignment faults in some circumstances. In general, the following rules should be applied when using data word declaration directives inside code sections: * .quad and .double: .align 3 * .long, .word, .single, .float: .align (or .align 2) * .short: No explicit alignment required, since Thumb-2 instructions are always 2 or 4 bytes in size. immediately after an instruction. Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-11-30ARM: 6497/1: kexec: Correct data alignment for CONFIG_THUMB2_KERNELDave Martin
Directives such as .long and .word do not magically cause the assembler location counter to become aligned in gas. As a result, using these directives in code sections can result in misaligned data words when building a Thumb-2 kernel (CONFIG_THUMB2_KERNEL). This is a Bad Thing, since the ABI permits the compiler to assume that fundamental types of word size or above are word- aligned when accessing them from C. If the data is not really word-aligned, this can cause impaired performance and stray alignment faults in some circumstances. In general, the following rules should be applied when using data word declaration directives inside code sections: * .quad and .double: .align 3 * .long, .word, .single, .float: .align (or .align 2) * .short: No explicit alignment required, since Thumb-2 instructions are always 2 or 4 bytes in size. immediately after an instruction. Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-11-30ARM: 6496/1: GIC: Do not try to register more then NR_IRQS interruptsPawel Moll
This change limits number of GIC-originating interrupts to the platform maximum (defined by NR_IRQS) while still initialising all distributor registers. Signed-off-by: Pawel Moll <pawel.moll@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-11-30ARM: pxa/palm: fix ifdef around gen_nand driver registrationMarek Vasut
Reported-by: Rafael Gandolfi <kaillasse91@hotmail.fr> Signed-off-by: Marek Vasut <marek.vasut@gmail.com> Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
2010-11-30ARM: pxa: fix pxa2xx-flash section mismatchMarek Vasut
Signed-off-by: Marek Vasut <marek.vasut@gmail.com> Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com> Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
2010-11-30ARM: mmp2: remove not used clk_rtcJason Chagas
RTC clock will remain at 32KHz and powered on, there is no need for it at this moment. Signed-off-by: Jason Chagas <jason.chagas@marvell.com> Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
2010-11-30s6105-ipcam: fix compilationDaniel Glöckner
When the s6105-ipcam ASoC driver had been converted to the multi-component API, a single reference to a former structure element remained, blocking successful compilation. Signed-off-by: Daniel Glöckner <daniel-gl@gmx.net> Acked-by: Liam Girdwood <lrg@slimlogic.co.uk> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2010-11-30s6000-pcm: fix compilationDaniel Glöckner
s6000_soc_platform has lost its forward declaration and there no longer is a name element in it, so use a string constant when calling request_irq. Signed-off-by: Daniel Glöckner <daniel-gl@gmx.net> Acked-by: Liam Girdwood <lrg@slimlogic.co.uk> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2010-11-30s6000-i2s: fix compilationDaniel Glöckner
A semicolon was missing. Signed-off-by: Daniel Glöckner <daniel-gl@gmx.net> Acked-by: Liam Girdwood <lrg@slimlogic.co.uk> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2010-11-30ASoC: Fix missing spin_unlock_irqrestoreAxel Lin
In nuc900_dma_hw_params(), if snd_pcm_lib_malloc_pages failed it returns without calling spin_unlock_irqrestore(). Since snd_pcm_lib_malloc_pages() does not touch struct nuc900_audio, we don't need to hold the lock while calling snd_pcm_lib_malloc_pages(). Fix it by moving spin_lock_irqsave() down to after snd_pcm_lib_malloc_pages(). In nuc900_dma_prepare(), spin_unlock_irqrestore() is missing in the error path. Fix it by removing the return in default case. Signed-off-by: Axel Lin <axel.lin@gmail.com> Acked-by: Wan ZongShun <mcuos.com@gmail.com> Acked-by: Liam Girdwood <lrg@slimlogic.co.uk> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2010-11-30GFS2: Clean up of gdlm_lock functionSteven Whitehouse
The DLM never returns -EAGAIN in response to dlm_lock(), and even if it did, the test in gdlm_lock() was wrong anyway. Once that test is removed, it is possible to greatly simplify this code by simply using a "normal" error return code (0 for success). We then no longer need the LM_OUT_ASYNC return code which can be removed. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-11-30GFS2: Allow gfs2 to update quota usage values through the quotactl interfaceAbhijith Das
With this patch the gfs2_set_dqblk() function will be able to update the quota usage block count (FS_DQ_BCOUNT) in addition to the already supported FS_DQ_BHARD (limit) and FS_DQ_BSOFT (warn) fields of the dquot structure. Signed-off-by: Abhi Das <adas@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-11-30GFS2: fs/gfs2/glock.h: Add __attribute__((format(printf,2,3)) to gfs2_print_dbgJoe Perches
Functions that use printf formatting, especially those that use %pV, should have their uses of printf format and arguments checked by the compiler. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-11-30GFS2: fs/gfs2/glock.c: Use printf extension %pVJoe Perches
Using %pV reduces the number of printk calls and eliminates any possible message interleaving from other printk calls. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-11-30GFS2: Clean up duplicated setattr codeSteven Whitehouse
While preparing the last patch I noticed that the gfs2_setattr_simple code had been duplicated into two other places. This patch updates those to call gfs2_setattr_simple rather than open coding it. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-11-30GFS2: Remove unreachable calls to vmtruncateSteven Whitehouse
Suggested-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-11-30GFS2: fs/gfs2/glock.c: Convert sprintf_symbol to %pSJoe Perches
Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-11-30GFS2: Change two WQ_RESCUERs into WQ_MEM_RECLAIMSteven Whitehouse
The WQ_RESCUER flag should only be used internally to the workqueue implementation. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Acked-by: Tejun Heo <tj@kernel.org>
2010-11-30at91: merge all at91rm9200 defconfig in one single fileEric Benard
About all options present in each file are activated in the single file. Signed-off-by: Eric Benard <eric@eukrea.com> Tested-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
2010-11-30sched: Fix unregister_fair_sched_group()Paul Turner
In the flipping and flopping between calling unregister_fair_sched_group() on a per-cpu versus per-group basis we ended up in a bad state. Remove from the list for the passed cpu as opposed to some arbitrary index. ( This fixes explosions w/ autogroup as well as a group creation/destruction stress test. ) Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Paul Turner <pjt@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20101130005740.080828123@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-30Revert "drm/i915/dp: use VBT provided eDP params if available"Chris Wilson
This reverts commit 869184a675662bddcdf76c5b95665272facff2b8. This is required for the Sony Vaio Jesse was working on at the time, but breaks most other eDP machines - machines that were working in earlier kernels. Reported-and-tested-by: Dave Airlie <airlied@redhat.com> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=31188 Tested-by: Zhao Jian <jian.j.zhao@intel.com> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
2010-11-30ARM: S3C2412: Fix typo in CONFIG_CPU_S3C2412_ONLY definitionYauhen Kharuzhy
Dependency on (CPU_S3C2416 is not selected) was defined as "!CPU_2416", instead of "!CPU_S3C2416". Fix it. Signed-off-by: Yauhen Kharuzhy <jekhor@gmail.com> Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2010-11-30ARM: S3C2443: Select properly ARM core typeYauhen Kharuzhy
Select ARM920T core when compiling kernel for s3c2443. Signed-off-by: Yauhen Kharuzhy <yauhen.kharuzhy@promwad.com> Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2010-11-30ARM: SMDK2416: Select MACH_SMDK, S3C_DEV_NAND, S3C_DEV_USB_HOSTYauhen Kharuzhy
Enable compilation of platform devices and initialization code used in SMDK2416 board file. Signed-off-by: Yauhen Kharuzhy <jekhor@gmail.com> Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2010-11-30ALSA: Fix SNDCTL_DSP_RESET ioctl for OSS emulationTakashi Iwai
In OSS emulation, SNDCTL_DSP_RESET ioctl needs the reset of the internal buffer state in addition to drop of the running streams. Otherwise the succeeding access becomes inconsistent. Tested-by: Amit Nagal <helloin.amit@gmail.com> Cc: <stable@kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2010-11-29rcu: Make synchronize_srcu_expedited() fast if running readersPaul E. McKenney
The synchronize_srcu_expedited() function is currently quick if there are no active readers, but will delay a full jiffy if there are any. If these readers leave their SRCU read-side critical sections quickly, this is way too long to wait. So this commit first waits ten microseconds, and only then falls back to jiffy-at-a-time waiting. Reported-by: Avi Kivity <avi@redhat.com> Reported-by: Marcelo Tosatti <mtosatti@redhat.com> Tested-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-11-29rcu: fix race condition in synchronize_sched_expedited()Paul E. McKenney
The new (early 2010) implementation of synchronize_sched_expedited() uses try_stop_cpu() to force a context switch on every CPU. It also permits concurrent calls to synchronize_sched_expedited() to share a single call to try_stop_cpu() through use of an atomically incremented synchronize_sched_expedited_count variable. Unfortunately, this is subject to failure as follows: o Task A invokes synchronize_sched_expedited(), try_stop_cpus() succeeds, but Task A is preempted before getting to the atomic increment of synchronize_sched_expedited_count. o Task B also invokes synchronize_sched_expedited(), with exactly the same outcome as Task A. o Task C also invokes synchronize_sched_expedited(), again with exactly the same outcome as Tasks A and B. o Task D also invokes synchronize_sched_expedited(), but only gets as far as acquiring the mutex within try_stop_cpus() before being preempted, interrupted, or otherwise delayed. o Task E also invokes synchronize_sched_expedited(), but only gets to the snapshotting of synchronize_sched_expedited_count. o Tasks A, B, and C all increment synchronize_sched_expedited_count. o Task E fails to get the mutex, so checks the new value of synchronize_sched_expedited_count. It finds that the value has increased, so (wrongly) assumes that its work has been done, returning despite there having been no expedited grace period since it began. The solution is to have the lowest-numbered CPU atomically increment the synchronize_sched_expedited_count variable within the synchronize_sched_expedited_cpu_stop() function, which is under the protection of the mutex acquired by try_stop_cpus(). However, this also requires that piggybacking tasks wait for three rather than two instances of try_stop_cpu(), because we cannot control the order in which the per-CPU callback function occur. Cc: Tejun Heo <tj@kernel.org> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-11-29rcu: update documentation/comments for Lai's adoption patchPaul E. McKenney
Lai's RCU-callback immediate-adoption patch changes the RCU tracing output, so update tracing.txt. Also update a few comments to clarify the synchronization design. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-11-29rcu,cleanup: simplify the code when cpu is dyingLai Jiangshan
When we handle the CPU_DYING notifier, the whole system is stopped except for the current CPU. We therefore need no synchronization with the other CPUs. This allows us to move any orphaned RCU callbacks directly to the list of any online CPU without needing to run them through the global orphan lists. These global orphan lists can therefore be dispensed with. This commit makes thes changes, though currently victimizes CPU 0 @@@. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-11-29rcu,cleanup: move synchronize_sched_expedited() out of sched.cLai Jiangshan
The first version of synchronize_sched_expedited() used the migration code in the scheduler, and was therefore implemented in kernel/sched.c. However, the more recent version of this code no longer uses the migration code, so this commit moves it to the main RCU source files. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-11-29rcu: get rid of obsolete "classic" names in TREE_RCU tracingPaul E. McKenney
The TREE_RCU tracing had obsolete rcuclassic_trace_init() and rcuclassic_trace_cleanup() function names. This commit brings them up to date: rcutree_trace_init() and rcutree_trace_cleanup(), respectively. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-11-29rcu: Distinguish between boosting and boostedPaul E. McKenney
RCU priority boosting's tracing did not distinguish between ongoing boosting and completion of boosting. This commit therefore adds this capability. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-11-29rcu: document TINY_RCU and TINY_PREEMPT_RCU tracing.Paul E. McKenney
Add the required verbiage to Documentation/RCU/trace.txt. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-11-29rcu: add tracing for TINY_RCU and TINY_PREEMPT_RCUPaul E. McKenney
Add tracing for the tiny RCU implementations, including statistics on boosting in the case of TINY_PREEMPT_RCU and RCU_BOOST. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-11-29rcu: priority boosting for TINY_PREEMPT_RCUPaul E. McKenney
Add priority boosting, but only for TINY_PREEMPT_RCU. This is enabled by the default-off RCU_BOOST kernel parameter. The priority to which to boost preempted RCU readers is controlled by the RCU_BOOST_PRIO kernel parameter (defaulting to real-time priority 1) and the time to wait before boosting the readers blocking a given grace period is controlled by the RCU_BOOST_DELAY kernel parameter (defaulting to 500 milliseconds). Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-11-30cifs: display fsc in /proc/mountsSuresh Jayaraman
Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de> Signed-off-by: Steve French <sfrench@us.ibm.com>
2010-11-30cifs: enable fscache iff fsc mount option is used explicitlySuresh Jayaraman
Currently, if CONFIG_CIFS_FSCACHE is set, fscache is enabled on files opened as read-only irrespective of the 'fsc' mount option. Fix this by enabling fscache only if 'fsc' mount option is specified explicitly. Remove an extraneous cFYI debug message and fix a typo while at it. Reported-by: Jeff Layton <jlayton@redhat.com> Acked-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de> Signed-off-by: Steve French <sfrench@us.ibm.com>
2010-11-30cifs: allow fsc mount option only if CONFIG_CIFS_FSCACHE is setSuresh Jayaraman
Currently, it is possible to specify 'fsc' mount option even if CONFIG_CIFS_FSCACHE has not been set. The option is being ignored silently while the user fscache functionality to work. Fix this by raising error when the CONFIG option is not set. Reported-by: Jeff Layton <jlayton@redhat.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de> Signed-off-by: Steve French <sfrench@us.ibm.com>