Messages in this thread | | | Subject | Re: [PATCH] livepatch: klp_send_signal should treat PF_IO_WORKER like PF_KTHREAD | From | Joe Lawrence <> | Date | Wed, 24 Mar 2021 22:51:46 -0400 |
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On 3/24/21 9:48 PM, Dong Kai wrote: > commit 15b2219facad ("kernel: freezer should treat PF_IO_WORKER like > PF_KTHREAD for freezing") is to fix the freezeing issue of IO threads
nit: s/freezeing/freezing
> by making the freezer not send them fake signals. > > Here live patching consistency model call klp_send_signals to wake up > all tasks by send fake signal to all non-kthread which only check the > PF_KTHREAD flag, so it still send signal to io threads which may lead to > freezeing issue of io threads. > > Here we take the same fix action by treating PF_IO_WORKERS as PF_KTHREAD > within klp_send_signal function. > > Signed-off-by: Dong Kai <dongkai11@huawei.com> > --- > note: > the io threads freeze issue links: > [1] https://lore.kernel.org/io-uring/YEgnIp43%2F6kFn8GL@kevinlocke.name/ > [2] https://lore.kernel.org/io-uring/d7350ce7-17dc-75d7-611b-27ebf2cb539b@kernel.dk/ > > kernel/livepatch/transition.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c > index f6310f848f34..0e1c35c8f4b4 100644 > --- a/kernel/livepatch/transition.c > +++ b/kernel/livepatch/transition.c > @@ -358,7 +358,7 @@ static void klp_send_signals(void) > * Meanwhile the task could migrate itself and the action > * would be meaningless. It is not serious though. > */ > - if (task->flags & PF_KTHREAD) { > + if (task->flags & (PF_KTHREAD | PF_IO_WORKER)) { > /* > * Wake up a kthread which sleeps interruptedly and > * still has not been migrated. >
(PF_KTHREAD | PF_IO_WORKER) is open coded in soo many places maybe this is a silly question, but...
If the livepatch code could use fake_signal_wake_up(), we could consolidate the pattern in klp_send_signals() with the one in freeze_task(). Then there would only one place for wake up / fake signal logic.
I don't fully understand the differences in the freeze_task() version, so I only pose this as a question and not v2 request.
As it is, this change seems logical to me, so: Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Thanks,
-- Joe
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