user/sven/linux.git/arch/Kconfig, branch v3.2.18

Add Kconfig option ARCH_HAVE_NMI_SAFE_CMPXCHG

2011-08-03T15:12:37Z

cmpxchg() is widely used by lockless code, including NMI-safe lockless code. But on some architectures, the cmpxchg() implementation is not NMI-safe, on these architectures the lockless code may need a spin_trylock_irqsave() based implementation. This patch adds a Kconfig option: ARCH_HAVE_NMI_SAFE_CMPXCHG, so that NMI-safe lockless code can depend on it or provide different implementation according to it. On many architectures, cmpxchg is only NMI-safe for several specific operand sizes. So, ARCH_HAVE_NMI_SAFE_CMPXCHG define in this patch only guarantees cmpxchg is NMI-safe for sizeof(unsigned long). Signed-off-by: Huang Ying Acked-by: Mike Frysinger Acked-by: Paul Mundt Acked-by: Hans-Christian Egtvedt Acked-by: Benjamin Herrenschmidt Acked-by: Chris Metcalf Acked-by: Richard Henderson CC: Mikael Starvik Acked-by: David Howells CC: Yoshinori Sato CC: Tony Luck CC: Hirokazu Takata CC: Geert Uytterhoeven CC: Michal Simek Acked-by: Ralf Baechle CC: Kyle McMartin CC: Martin Schwidefsky CC: Chen Liqin CC: "David S. Miller" CC: Ingo Molnar CC: Chris Zankel Signed-off-by: Len Brown

mm, powerpc: move the RCU page-table freeing into generic code

2011-05-25T15:39:16Z

In case other architectures require RCU freed page-tables to implement gup_fast() and software filled hashes and similar things, provide the means to do so by moving the logic into generic code. Signed-off-by: Peter Zijlstra Requested-by: David Miller Cc: Benjamin Herrenschmidt Cc: Martin Schwidefsky Cc: Russell King Cc: Paul Mundt Cc: Jeff Dike Cc: Richard Weinberger Cc: Tony Luck Cc: KAMEZAWA Hiroyuki Cc: Hugh Dickins Cc: Mel Gorman Cc: KOSAKI Motohiro Cc: Nick Piggin Cc: Namhyung Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

arch:Kconfig.locks Remove unused config option.

2011-04-10T15:01:05Z

Signed-off-by: Justin P. Mattock Acked-by: Steven Rostedt Acked-by: Heiko Carstens Signed-off-by: Jiri Kosina

mutexes, sched: Introduce arch_mutex_cpu_relax()

2010-11-26T14:05:34Z

The spinning mutex implementation uses cpu_relax() in busy loops as a compiler barrier. Depending on the architecture, cpu_relax() may do more than needed in this specific mutex spin loops. On System z we also give up the time slice of the virtual cpu in cpu_relax(), which prevents effective spinning on the mutex. This patch replaces cpu_relax() in the spinning mutex code with arch_mutex_cpu_relax(), which can be defined by each architecture that selects HAVE_ARCH_MUTEX_CPU_RELAX. The default is still cpu_relax(), so this patch should not affect other architectures than System z for now. Signed-off-by: Gerald Schaefer Signed-off-by: Peter Zijlstra LKML-Reference: <1290437256.7455.4.camel@thinkpad> Signed-off-by: Ingo Molnar

jump label: Add work around to i386 gcc asm goto bug

2010-10-29T18:45:29Z

On i386 (not x86_64) early implementations of gcc would have a bug with asm goto causing it to produce code like the following: (This was noticed by Peter Zijlstra) 56 pushl 0 67 nopl jmp 0x6f popl jmp 0x8c 6f mov test je 0x8c 8c mov call *(%esp) The jump added in the asm goto skipped over the popl that matched the pushl 0, which lead up to a quick crash of the system when the jump was enabled. The nopl is defined in the asm goto () statement and when tracepoints are enabled, the nop changes to a jump to the label that was specified by the asm goto. asm goto is suppose to tell gcc that the code in the asm might jump to an external label. Here gcc obviously fails to make that work. The bug report for gcc is here: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46226 The bug only appears on x86 when not compiled with -maccumulate-outgoing-args. This option is always set on x86_64 and it is also the work around for a function graph tracer i386 bug. (See commit: 746357d6a526d6da9d89a2ec645b28406e959c2e) This explains why the bug only showed up on i386 when function graph tracer was not enabled. This patch now adds a CONFIG_JUMP_LABEL option that is default off instead of using jump labels by default. When jump labels are enabled, the -maccumulate-outgoing-args will be used (causing a slightly larger kernel image on i386). This option will exist until we have a way to detect if the gcc compiler in use is safe to use on all configurations without the work around. Note, there exists such a test, but for now we will keep the enabling of jump label as a manual option. Archs that know the compiler is safe with asm goto, may choose to select JUMP_LABEL and enable it by default. Reported-by: Ingo Molnar Cause-discovered-by: Peter Zijlstra Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Jason Baron Cc: H. Peter Anvin Cc: David Daney Cc: Mathieu Desnoyers Cc: Masami Hiramatsu Cc: David Miller Cc: Richard Henderson LKML-Reference: <1288028746.3673.11.camel@laptop> Signed-off-by: Steven Rostedt

Merge branch 'tip/perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core

2010-09-24T07:12:05Z

jump label: Base patch for jump label

2010-09-22T20:29:41Z

base patch to implement 'jump labeling'. Based on a new 'asm goto' inline assembly gcc mechanism, we can now branch to labels from an 'asm goto' statment. This allows us to create a 'no-op' fastpath, which can subsequently be patched with a jump to the slowpath code. This is useful for code which might be rarely used, but which we'd like to be able to call, if needed. Tracepoints are the current usecase that these are being implemented for. Acked-by: David S. Miller Signed-off-by: Jason Baron LKML-Reference: [ cleaned up some formating ] Signed-off-by: Steven Rostedt

kprobes: Fix Kconfig dependency

2010-09-13T18:41:31Z

Fix Kconfig dependency among Kprobes, optprobe and kallsyms. Kprobes uses kallsyms_lookup for finding target function and checking instruction boundary, thus CONFIG_KPROBES should select CONFIG_KALLSYMS. Optprobe is an optional feature which is supported on x86 arch, and it also uses kallsyms_lookup for checking instructions in the target function. Since KALLSYMS_ALL just adds symbols of kernel variables, it doesn't need to select KALLSYMS_ALL. Signed-off-by: Masami Hiramatsu Acked-by: Randy Dunlap , Cc: Ananth N Mavinakayanahalli Cc: Felipe Contreras Cc: Randy Dunlap Cc: Ananth N Mavinakayanahalli Cc: Anil S Keshavamurthy Cc: David S. Miller Cc: akpm LKML-Reference: <20100913102541.20260.85700.stgit@ltc236.sdl.hitachi.co.jp> Signed-off-by: Ingo Molnar

Merge branch 'perf/nmi' into perf/core

2010-08-05T06:45:05Z

Conflicts: kernel/Makefile Merge reason: Add the now complete topic, fix the conflict. Signed-off-by: Ingo Molnar

lockup_detector: Introduce CONFIG_HARDLOCKUP_DETECTOR

2010-05-15T23:57:42Z

This new config is deemed to simplify even more the lockup detector dependencies and can make it easier to bring a smooth sorting between archs that support the new generic lockup detector and those that still have their own, especially for those that are in the middle of this migration. Instead of checking whether we have CONFIG_LOCKUP_DETECTOR + CONFIG_PERF_EVENTS_NMI each time an arch wants to know if it needs to build its own lockup detector, take a shortcut with this new config. It is enabled only if the hardlockup detection part of the whole lockup detector is on. Signed-off-by: Frederic Weisbecker Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Don Zickus Cc: Cyrill Gorcunov