https://github.com/torvalds/linux
Revision 7b2b55da1db10a5525460633ae4b6fb0be060c41 authored by Jason Xing on 25 August 2019, 00:54:53 UTC, committed by Linus Torvalds on 25 August 2019, 02:48:42 UTC
Only when calling the poll syscall the first time can user receive POLLPRI correctly. After that, user always fails to acquire the event signal. Reproduce case: 1. Get the monitor code in Documentation/accounting/psi.txt 2. Run it, and wait for the event triggered. 3. Kill and restart the process. The question is why we can end up with poll_scheduled = 1 but the work not running (which would reset it to 0). And the answer is because the scheduling side sees group->poll_kworker under RCU protection and then schedules it, but here we cancel the work and destroy the worker. The cancel needs to pair with resetting the poll_scheduled flag. Link: http://lkml.kernel.org/r/1566357985-97781-1-git-send-email-joseph.qi@linux.alibaba.com Signed-off-by: Jason Xing <kerneljasonxing@linux.alibaba.com> Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com> Reviewed-by: Caspar Zhang <caspar@linux.alibaba.com> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Tip revision: 7b2b55da1db10a5525460633ae4b6fb0be060c41 authored by Jason Xing on 25 August 2019, 00:54:53 UTC
psi: get poll_work to run when calling poll syscall next time
psi: get poll_work to run when calling poll syscall next time
Tip revision: 7b2b55d
File | Mode | Size |
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ChangeLog | -rw-r--r-- | 14.0 KB |
Kconfig | -rw-r--r-- | 957 bytes |
Makefile | -rw-r--r-- | 246 bytes |
TODO | -rw-r--r-- | 385 bytes |
befs.h | -rw-r--r-- | 3.0 KB |
befs_fs_types.h | -rw-r--r-- | 5.0 KB |
btree.c | -rw-r--r-- | 21.9 KB |
btree.h | -rw-r--r-- | 343 bytes |
datastream.c | -rw-r--r-- | 15.9 KB |
datastream.h | -rw-r--r-- | 575 bytes |
debug.c | -rw-r--r-- | 7.1 KB |
endian.h | -rw-r--r-- | 3.2 KB |
inode.c | -rw-r--r-- | 1.2 KB |
inode.h | -rw-r--r-- | 120 bytes |
io.c | -rw-r--r-- | 1.4 KB |
io.h | -rw-r--r-- | 110 bytes |
linuxvfs.c | -rw-r--r-- | 25.5 KB |
super.c | -rw-r--r-- | 3.3 KB |
super.h | -rw-r--r-- | 131 bytes |
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