user/sven/linux.git/include/linux/thread_info.h, branch v3.14.29

x86,preempt: Fix preemption for i386

2014-05-31T20:20:28Z

Many people reported preemption/reschedule problems with i386 kernels for .13 and .14. After Michele bisected this to a combination of 3e8e42c69bb ("sched: Revert need_resched() to look at TIF_NEED_RESCHED") ded79754754 ("irq: Force hardirq exit's softirq processing on its own stack") it finally dawned on me that i386's current_thread_info() was to blame. When we are on interrupt/exception stacks, we fail to observe the right TIF_NEED_RESCHED bit and therefore the PREEMPT_NEED_RESCHED folding malfunctions. Current upstream fixes this by making i386 behave the same as x86_64 already did: 2432e1364bbe ("x86: Nuke the supervisor_stack field in i386 thread_info") b807902a88c4 ("x86: Nuke GET_THREAD_INFO_WITH_ESP() macro for i386") 0788aa6a23cb ("x86: Prepare removal of previous_esp from i386 thread_info structure") 198d208df437 ("x86: Keep thread_info on thread stack in x86_32") However, that is far too much to stuff into -stable. Therefore I propose we merge the below patch which uses task_thread_info(current) for tif_need_resched() instead of the ESP based current_thread_info(). This makes sure we always observe the one true TIF_NEED_RESCHED bit and things will work as expected again. Cc: bp@alien8.de Cc: fweisbec@gmail.com Cc: david.a.cohen@linux.intel.com Cc: mingo@kernel.org Cc: fweisbec@gmail.com Cc: greg@kroah.com Cc: Steven Rostedt Cc: gregkh@linuxfoundation.org Cc: pbonzini@redhat.com Cc: rostedt@goodmis.org Cc: stefan.bader@canonical.com Cc: mingo@kernel.org Cc: toralf.foerster@gmx.de Cc: David Cohen Cc: Steven Rostedt Cc: torvalds@linux-foundation.org Cc: Paolo Bonzini Cc: David Cohen Cc: Cc: Borislav Petkov Cc: Paolo Bonzini Cc: Cc: Borislav Petkov Cc: peterz@infradead.org Cc: Linus Torvalds Cc: barra_cuda@katamail.com Tested-by: Stefan Bader Tested-by: Toralf F¿rster Tested-by: Michele Ballabio Signed-off-by: Greg Kroah-Hartman Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/20140409142447.GD13658@twins.programming.kicks-ass.net

sched, idle: Fix the idle polling state logic

2013-09-25T11:53:10Z

Mike reported that commit 7d1a9417 ("x86: Use generic idle loop") regressed several workloads and caused excessive reschedule interrupts. The patch in question failed to notice that the x86 code had an inverted sense of the polling state versus the new generic code (x86: default polling, generic: default !polling). Fix the two prominent x86 mwait based idle drivers and introduce a few new generic polling helpers (fixing the wrong smp_mb__after_clear_bit usage). Also switch the idle routines to using tif_need_resched() which is an immediate TIF_NEED_RESCHED test as opposed to need_resched which will end up being slightly different. Reported-by: Mike Galbraith Signed-off-by: Peter Zijlstra Cc: lenb@kernel.org Cc: tglx@linutronix.de Link: http://lkml.kernel.org/n/tip-nc03imb0etuefmzybzj7sprf@git.kernel.org Signed-off-by: Ingo Molnar

sched: Remove {set,clear}_need_resched

2013-09-25T11:53:09Z

Preemption semantics are going to change which mandate a change. All DRM usage sites are already broken and will not be affected (much) by this change. DRM people are aware and will remove the last few stragglers. For now, leave an empty stub that generates a warning, once all users are gone we can remove this. Signed-off-by: Peter Zijlstra Cc: airlied@linux.ie Cc: daniel.vetter@ffwll.ch Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/n/tip-qfc1el2zvhxiyut4ai99ij4n@git.kernel.org Signed-off-by: Ingo Molnar

fork: protect architectures where THREAD_SIZE >= PAGE_SIZE against fork bombs

2012-12-18T23:02:13Z

Because those architectures will draw their stacks directly from the page allocator, rather than the slab cache, we can directly pass __GFP_KMEMCG flag, and issue the corresponding free_pages. This code path is taken when the architecture doesn't define CONFIG_ARCH_THREAD_INFO_ALLOCATOR (only ia64 seems to), and has THREAD_SIZE >= PAGE_SIZE. Luckily, most - if not all - of the remaining architectures fall in this category. This will guarantee that every stack page is accounted to the memcg the process currently lives on, and will have the allocations to fail if they go over limit. For the time being, I am defining a new variant of THREADINFO_GFP, not to mess with the other path. Once the slab is also tracked by memcg, we can get rid of that flag. Tested to successfully protect against :(){ :|:& };: Signed-off-by: Glauber Costa Acked-by: Frederic Weisbecker Acked-by: Kamezawa Hiroyuki Reviewed-by: Michal Hocko Cc: Christoph Lameter Cc: David Rientjes Cc: Greg Thelen Cc: Johannes Weiner Cc: JoonSoo Kim Cc: Mel Gorman Cc: Pekka Enberg Cc: Rik van Riel Cc: Suleiman Souhlal Cc: Tejun Heo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

set_restore_sigmask() is never called without SIGPENDING (and never should be)

2012-06-01T16:58:50Z

Signed-off-by: Al Viro

new helpers: {clear,test,test_and_clear}_restore_sigmask()

2012-06-01T16:58:47Z

helpers parallel to set_restore_sigmask(), used in the next commits Signed-off-by: Al Viro

HAVE_RESTORE_SIGMASK is defined on all architectures now

2012-06-01T16:58:46Z

Everyone either defines it in arch thread_info.h or has TIF_RESTORE_SIGMASK and picks default set_restore_sigmask() in linux/thread_info.h. Kill the ifdefs, slap #error in linux/thread_info.h to catch breakage when new ones get merged. Signed-off-by: Al Viro

fork: Move thread info gfp flags to header

2012-05-08T11:55:20Z

These flags can be useful for extra allocations outside of the core code. Add __GFP_NOTRACK to them, so the archs which have kmemcheck do not have to provide extra allocators just for that reason. Signed-off-by: Thomas Gleixner Link: http://lkml.kernel.org/r/20120505150141.428211694@linutronix.de

hrtimers: Avoid touching inactive timer bases

2011-05-23T11:59:54Z

Instead of iterating over all possible timer bases avoid it by marking the active bases in the cpu base. Signed-off-by: Thomas Gleixner Reviewed-by: Peter Zijlstra

thread_info: Remove legacy arg0-3 from restart_block

2011-02-02T14:28:13Z

posix timers were the last users of the legacy arg0-3 members of restart_block. Remove the cruft. Signed-off-by: Thomas Gleixner Acked-by: John Stultz Tested-by: Richard Cochran LKML-Reference: <20110201134418.326209775@linutronix.de>