On Mon, 30 Mar 2015 11:07:35 +0000 (GMT) Maninder Singh <maninder...@samsung.com> wrote:
> Hello All, > > Avoid waking up every thread sleeping in a restart_syscall call during > suspend and resume by calling a freezable blocking call. > Previous patches modified the freezer to avoid sending wakeups to threads > that are blocked in freezable blocking calls. > Ref: https://lkml.org/lkml/2013/5/1/424 > We have faced similiar issue of sleep fail when calling restart() system call > in stress testing. > > Patch :- > Subject: restart_syscall: use freezable blocking call > Avoid waking up every thread sleeping in a restart_syscall call during > suspend and resume by calling a freezable blocking call. Previous > patches modified the freezer to avoid sending wakeups to threads > that are blocked in freezable blocking calls. This patch is rather mucked up - tabs replaced with spaces, apparently mangled text in the changelog. Thomas is having a bit of time off, so I fixed most of that up and queued the patch in -mm for some testing. Hopefully Thomas and/or Rafael will be able to comment? From: Maninder Singh <maninder...@samsung.com> Subject: kernel/time/hrtimer.c: restart_syscall: use freezable blocking call Avoid waking up every thread sleeping in a restart_syscall call during suspend and resume by calling a freezable blocking call. Previous patches modified the freezer to avoid sending wakeups to threads that are blocked in freezable blocking calls. Ref: https://lkml.org/lkml/2013/5/1/424 Backtrace: [<c03e3924>] (__schedule+0x0/0x5d8) from [<c03e3f88>] (schedule+0x8c/0x90) [<c03e3efc>] (schedule+0x0/0x90) from [<c03e3150>] (schedule_hrtimeout_range_clock+0xdc/0x110) [<c03e3074>] (schedule_hrtimeout_range_clock+0x0/0x110) from [<c03e31a0>] (schedule_hrtimeout_range+0x1c/0x20) r9:d16c9be0 r8:8b7d9c2c r7:00000000 r6:00000000 r5:d16c8028 [<c03e3184>] (schedule_hrtimeout_range+0x0/0x20) from [<c015778c>] (poll_schedule_timeout+0x48/0x6c) [<c0157744>] (poll_schedule_timeout+0x0/0x6c) from [<c0158994>] (do_sys_poll+0x2c8/0x378) r5:d16c9f78 r4:00000000 [<c01586cc>] (do_sys_poll+0x0/0x378) from [<c0158a84>] (do_restart_poll+0x40/0x5c) [<c0158a44>] (do_restart_poll+0x0/0x5c) from [<c005710c>] (sys_restart_syscall+0x2c/0x30) r4:fffffe7a [<c00570e0>] (sys_restart_syscall+0x0/0x30) from [<c001a180>] (ret_fast_syscall+0x0/0x48) Signed-off-by: Yogesh Gaur <yn.gaur <at> samsung.com> Signed-off-by: Amit Arora <amit.arora <at> samsung.com> Reviewed-by : Ajeet Yadav <ajeet.y <at> samsung.com> Cc: Thomas Gleixner <t...@linutronix.de> Cc: "Rafael J. Wysocki" <r...@rjwysocki.net> Signed-off-by: Andrew Morton <a...@linux-foundation.org> --- kernel/time/hrtimer.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff -puN kernel/time/hrtimer.c~restart_syscall-use-freezable-blocking-call kernel/time/hrtimer.c --- a/kernel/time/hrtimer.c~restart_syscall-use-freezable-blocking-call +++ a/kernel/time/hrtimer.c @@ -1767,7 +1767,7 @@ schedule_hrtimeout_range_clock(ktime_t * * A NULL parameter means "infinite" */ if (!expires) { - schedule(); + freezable_schedule(); return -EINTR; } @@ -1781,7 +1781,7 @@ schedule_hrtimeout_range_clock(ktime_t * t.task = NULL; if (likely(t.task)) - schedule(); + freezable_schedule(); hrtimer_cancel(&t.timer); destroy_hrtimer_on_stack(&t.timer); _ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
