From: Oleg Nesterov <oleg@redhat.com>
To: Mateusz Guzik <mjguzik@gmail.com>
Cc: Breno Leitao <leitao@debian.org>,
Christian Brauner <brauner@kernel.org>,
Jens Axboe <axboe@kernel.dk>,
Alexander Viro <viro@zeniv.linux.org.uk>, Jan Kara <jack@suse.cz>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
io-uring@vger.kernel.org, Alexey Gladkov <legion@kernel.org>
Subject: Re: [PATCH 0/1] pipe: only enable the extra wake_up(rd_wait) when epoll is actually used
Date: Fri, 24 Jul 2026 16:54:30 +0200 [thread overview]
Message-ID: <amN8ppPXRiUdiVKM@redhat.com> (raw)
In-Reply-To: <CAGudoHGiKYfF6L1yFy+QZgQaTt5ULnp6rgRaZE=6BANkpjrb7g@mail.gmail.com>
On 07/24, Mateusz Guzik wrote:
>
> On Fri, Jul 24, 2026 at 3:58 PM Oleg Nesterov <oleg@redhat.com> wrote:
> >
> > This means that io_uring depends on the "nasty semantics" too, io_poll_wake()
> > path should add the task work which calls io_req_post_cqe() every time the new
> > data arrives, even if the pipe was not empty.
> >
>
> well io_uring could set the flag as well in that case? it does not
> inherently mean random select and poll consumers definitely need this.
How? I don't think io_uring can do this. It doesn't even know if the file
is pipe or not. Only file_operations->poll() does know...
__Perhaps__ pipe_poll() could check something like wait->_key & EPOLLET to
detect both epoll/io_uring... Not sure, probably not, I'll try to check later.
Oleg.
prev parent reply other threads:[~2026-07-24 14:54 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-23 14:51 [PATCH 0/1] pipe: only enable the extra wake_up(rd_wait) when epoll is actually used Oleg Nesterov
2026-07-23 14:52 ` [PATCH 1/1] " Oleg Nesterov
2026-07-23 16:41 ` Mateusz Guzik
2026-07-23 15:10 ` [PATCH 0/1] " Oleg Nesterov
2026-07-24 13:58 ` Oleg Nesterov
2026-07-24 14:43 ` Mateusz Guzik
2026-07-24 14:54 ` Oleg Nesterov [this message]
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