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>
1 parent bb65f89
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 |
|---|---|---|
| Kconfig | -rw-r--r-- | 4.1 KB |
| Makefile | -rw-r--r-- | 870 bytes |
| array.c | -rw-r--r-- | 21.1 KB |
| base.c | -rw-r--r-- | 88.3 KB |
| cmdline.c | -rw-r--r-- | 415 bytes |
| consoles.c | -rw-r--r-- | 1.9 KB |
| cpuinfo.c | -rw-r--r-- | 698 bytes |
| devices.c | -rw-r--r-- | 1.1 KB |
| fd.c | -rw-r--r-- | 7.7 KB |
| fd.h | -rw-r--r-- | 539 bytes |
| generic.c | -rw-r--r-- | 17.5 KB |
| inode.c | -rw-r--r-- | 11.8 KB |
| internal.h | -rw-r--r-- | 8.5 KB |
| interrupts.c | -rw-r--r-- | 841 bytes |
| kcore.c | -rw-r--r-- | 15.5 KB |
| kmsg.c | -rw-r--r-- | 1.5 KB |
| loadavg.c | -rw-r--r-- | 880 bytes |
| meminfo.c | -rw-r--r-- | 5.1 KB |
| namespaces.c | -rw-r--r-- | 4.1 KB |
| nommu.c | -rw-r--r-- | 2.7 KB |
| page.c | -rw-r--r-- | 7.0 KB |
| proc_net.c | -rw-r--r-- | 9.7 KB |
| proc_sysctl.c | -rw-r--r-- | 41.6 KB |
| proc_tty.c | -rw-r--r-- | 4.5 KB |
| root.c | -rw-r--r-- | 7.6 KB |
| self.c | -rw-r--r-- | 1.7 KB |
| softirqs.c | -rw-r--r-- | 741 bytes |
| stat.c | -rw-r--r-- | 6.0 KB |
| task_mmu.c | -rw-r--r-- | 45.5 KB |
| task_nommu.c | -rw-r--r-- | 6.6 KB |
| thread_self.c | -rw-r--r-- | 1.9 KB |
| uptime.c | -rw-r--r-- | 922 bytes |
| util.c | -rw-r--r-- | 383 bytes |
| version.c | -rw-r--r-- | 515 bytes |
| vmcore.c | -rw-r--r-- | 40.2 KB |
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