linux/kernel, branch v3.12

perf: Fix perf ring buffer memory ordering

2013-10-29T11:01:19Z

The PPC64 people noticed a missing memory barrier and crufty old comments in the perf ring buffer code. So update all the comments and add the missing barrier. When the architecture implements local_t using atomic_long_t there will be double barriers issued; but short of introducing more conditional barrier primitives this is the best we can do. Reported-by: Victor Kaplansky Tested-by: Victor Kaplansky Signed-off-by: Peter Zijlstra Cc: Mathieu Desnoyers Cc: michael@ellerman.id.au Cc: Paul McKenney Cc: Michael Neuling Cc: Frederic Weisbecker Cc: anton@samba.org Cc: benh@kernel.crashing.org Link: http://lkml.kernel.org/r/20131025173749.GG19466@laptop.lan Signed-off-by: Ingo Molnar

Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2013-10-27T17:29:25Z

Pull timer fix from Ingo Molnar: "This tree contains a clockevents regression fix for certain ARM subarchitectures" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: clockevents: Sanitize ticks to nsec conversion

Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2013-10-27T17:28:35Z

Pull perf fixes from Ingo Molnar: "The tree contains three fixes: - Two tooling fixes - Reversal of the new 'MMAP2' extended mmap record ABI, introduced in this merge window. (Patches were proposed to fix it but it was all a bit late and we felt it's safer to just delay the ABI one more kernel release and do it right)" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Disable PERF_RECORD_MMAP2 support perf scripting perl: Fix build error on Fedora 12 perf probe: Fix to initialize fname always before use it

Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2013-10-27T17:18:15Z

Pull locking fix from Ingo Molnar: "This tree fixes a boot crash in CONFIG_DEBUG_MUTEXES=y kernels, on kernels built with GCC 3.x (there are still such distros)" Side note: it's not just a fix for old gcc versions, it's also removing an incredibly broken/subtle check that LLVM had issues with, and that made no sense. * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: mutex: Avoid gcc version dependent __builtin_constant_p() usage

Merge tag 'pm+acpi-3.12-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2013-10-26T03:38:47Z

Pull ACPI and power management fixes from "These fix two bugs in the intel_pstate driver, a hibernate bug leading to nasty resume failures sometimes and acpi-cpufreq initialization bug that causes problems to happen during module unload when intel_pstate is in use. Specifics: - Fix for rounding errors in intel_pstate causing CPU utilization to be underestimated from Brennan Shacklett. - intel_pstate fix to always use the correct max pstate value when computing the min pstate from Dirk Brandewie. - Hibernation fix for deadlocking resume in cases when the probing of the device containing the image is deferred from Russ Dill. - acpi-cpufreq fix to prevent the module from staying in memory when the driver cannot be registered and then attempting to unregister things that have never been registered on exit" * tag 'pm+acpi-3.12-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: acpi-cpufreq: Fail initialization if driver cannot be registered PM / hibernate: Move software_resume to late_initcall_sync intel_pstate: Correct calculation of min pstate value intel_pstate: Improve accuracy by not truncating until final result

PM / hibernate: Move software_resume to late_initcall_sync

2013-10-24T23:58:49Z

software_resume is being called after deferred_probe_initcall in drivers base. If the probing of the device that contains the resume image is deferred, and the system has been instructed to wait for it to show up, this wait will occur in software_resume. This causes a deadlock. Move software_resume into late_initcall_sync so that it happens after all the other late_initcalls. Signed-off-by: Russ Dill Acked-by: Pavel Machek Signed-off-by: Rafael J. Wysocki

clockevents: Sanitize ticks to nsec conversion

2013-10-23T10:51:21Z

Marc Kleine-Budde pointed out, that commit 77cc982 "clocksource: use clockevents_config_and_register() where possible" caused a regression for some of the converted subarchs. The reason is, that the clockevents core code converts the minimal hardware tick delta to a nanosecond value for core internal usage. This conversion is affected by integer math rounding loss, so the backwards conversion to hardware ticks will likely result in a value which is less than the configured hardware limitation. The affected subarchs used their own workaround (SIGH!) which got lost in the conversion. The solution for the issue at hand is simple: adding evt->mult - 1 to the shifted value before the integer divison in the core conversion function takes care of it. But this only works for the case where for the scaled math mult/shift pair "mult <= 1 << shift" is true. For the case where "mult > 1 << shift" we can apply the rounding add only for the minimum delta value to make sure that the backward conversion is not less than the given hardware limit. For the upper bound we need to omit the rounding add, because the backwards conversion is always larger than the original latch value. That would violate the upper bound of the hardware device. Though looking closer at the details of that function reveals another bogosity: The upper bounds check is broken as well. Checking for a resulting "clc" value greater than KTIME_MAX after the conversion is pointless. The conversion does: u64 clc = (latch << evt->shift) / evt->mult; So there is no sanity check for (latch << evt->shift) exceeding the 64bit boundary. The latch argument is "unsigned long", so on a 64bit arch the handed in argument could easily lead to an unnoticed shift overflow. With the above rounding fix applied the calculation before the divison is: u64 clc = (latch << evt->shift) + evt->mult - 1; So we need to make sure, that neither the shift nor the rounding add is overflowing the u64 boundary. [ukl: move assignment to rnd after eventually changing mult, fix build issue and correct comment with the right math] Signed-off-by: Thomas Gleixner Cc: Russell King - ARM Linux Cc: Marc Kleine-Budde Cc: nicolas.ferre@atmel.com Cc: Marc Pignat Cc: john.stultz@linaro.org Cc: kernel@pengutronix.de Cc: Ronald Wahl Cc: LAK Cc: Ludovic Desroches Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1380052223-24139-1-git-send-email-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König

Merge branch 'for-3.12-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

2013-10-22T07:20:34Z

Pull cgroup fixes from Tejun Heo: "Two late fixes for cgroup. One fixes descendant walk introduced during this rc1 cycle. The other fixes a post 3.9 bug during task attach which can lead to hang. Both fixes are critical and the fixes are relatively straight-forward" * 'for-3.12-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: fix to break the while loop in cgroup_attach_task() correctly cgroup: fix cgroup post-order descendant walk of empty subtree

Merge tag 'perf-urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

2013-10-20T08:51:35Z

Pull perf/urgent fixes from Arnaldo Carvalho de Melo: " * Fix build error on Fedora 12. * Fix to initialize fname always before use it, bug introduced during this merge window, from Masami Hiramatsu. * Disable PERF_RECORD_MMAP2 support, from Stephane Eranian. " Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Ingo Molnar

mutex: Avoid gcc version dependent __builtin_constant_p() usage

2013-10-18T19:58:54Z

Commit 040a0a37 ("mutex: Add support for wound/wait style locks") used "!__builtin_constant_p(p == NULL)" but gcc 3.x cannot handle such expression correctly, leading to boot failure when built with CONFIG_DEBUG_MUTEXES=y. Fix it by explicitly passing a bool which tells whether p != NULL or not. [ PeterZ: This is a sad patch, but provided it actually generates similar code I suppose its the best we can do bar whole sale deprecating gcc-3. ] Signed-off-by: Tetsuo Handa Acked-by: Peter Zijlstra Acked-by: Maarten Lankhorst Cc: peterz@infradead.org Cc: imirkin@alum.mit.edu Cc: daniel.vetter@ffwll.ch Cc: robdclark@gmail.com Cc: Linus Torvalds Cc: Andrew Morton Link: http://lkml.kernel.org/r/201310171945.AGB17114.FSQVtHOJFOOFML@I-love.SAKURA.ne.jp Signed-off-by: Ingo Molnar