Re: [PATCH 0/4] cancel all reqs of an exiting task

From: Jens Axboe
Date: Sun Jun 07 2020 - 20:12:25 EST


On 6/7/20 9:32 AM, Pavel Begunkov wrote:
> io_uring_flush() {
> ...
> if (fatal_signal_pending(current) || (current->flags & PF_EXITING))
> io_wq_cancel_pid(ctx->io_wq, task_pid_vnr(current));
> }
>
> This cancels only the first matched request. The pathset is mainly
> about fixing that. [1,2] are preps, [3/4] is the fix.
>
> The [4/4] tries to improve the worst case for io_uring_cancel_files(),
> that's when they are a lot of inflights with ->files. Instead of doing
> {kill(); wait();} one by one, it cancels all of them at once.
>
> Pavel Begunkov (4):
> io-wq: reorder cancellation pending -> running
> io-wq: add an option to cancel all matched reqs
> io_uring: cancel all task's requests on exit
> io_uring: batch cancel in io_uring_cancel_files()
>
> fs/io-wq.c | 108 ++++++++++++++++++++++++++------------------------
> fs/io-wq.h | 3 +-
> fs/io_uring.c | 29 ++++++++++++--
> 3 files changed, 83 insertions(+), 57 deletions(-)

Can you rebase this to include the changing of using ->task_pid to
->task instead? See:

https://lore.kernel.org/io-uring/87a71jjbzr.fsf@xxxxxxxxxxxxxxxxxxxxx/T/#u

Might as well do it at the same time, imho, since the cancel-by-task is
being reworked anyway.

--
Jens Axboe