From: Miklos Szeredi <miklos@szeredi.hu>
To: Pavel Begunkov <asml.silence@gmail.com>
Cc: Pavel Machek <pavel@denx.de>,
Greg KH <gregkh@linuxfoundation.org>,
Jan Ziak <0xe2.0x9a.0x9b@gmail.com>,
Linux API <linux-api@vger.kernel.org>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-kselftest@vger.kernel.org,
linux-man <linux-man@vger.kernel.org>,
Michael Kerrisk <mtk.manpages@gmail.com>,
shuah@kernel.org, Al Viro <viro@zeniv.linux.org.uk>,
io-uring@vger.kernel.org
Subject: Re: [PATCH 0/3] readfile(2): a new syscall to make open/read/close faster
Date: Wed, 15 Jul 2020 10:41:22 +0200 [thread overview]
Message-ID: <CAJfpegvkw5Exptz=gY5bRy2U8GjvTo+muBHsgdF_PA5=hyhmSA@mail.gmail.com> (raw)
In-Reply-To: <7584d754-2044-a892-cf29-65259b9c4eb1@gmail.com>
On Wed, Jul 15, 2020 at 10:33 AM Pavel Begunkov <asml.silence@gmail.com> wrote:
>
> On 14/07/2020 14:55, Miklos Szeredi wrote:
> > On Tue, Jul 14, 2020 at 1:36 PM Pavel Begunkov <asml.silence@gmail.com> wrote:
> >>
> >> On 14/07/2020 11:07, Miklos Szeredi wrote:
> >>> On Tue, Jul 14, 2020 at 8:51 AM Pavel Machek <pavel@denx.de> wrote:
> >>>>
> >>>> Hi!
> >>>>
> >>>>>> At first, I thought that the proposed system call is capable of
> >>>>>> reading *multiple* small files using a single system call - which
> >>>>>> would help increase HDD/SSD queue utilization and increase IOPS (I/O
> >>>>>> operations per second) - but that isn't the case and the proposed
> >>>>>> system call can read just a single file.
> >>>>>
> >>>>> If you want to do this for multple files, use io_ring, that's what it
> >>>>> was designed for. I think Jens was going to be adding support for the
> >>>>> open/read/close pattern to it as well, after some other more pressing
> >>>>> features/fixes were finished.
> >>>>
> >>>> What about... just using io_uring for single file, too? I'm pretty
> >>>> sure it can be wrapped in a library that is simple to use, avoiding
> >>>> need for new syscall.
> >>>
> >>> Just wondering: is there a plan to add strace support to io_uring?
> >>> And I don't just mean the syscalls associated with io_uring, but
> >>> tracing the ring itself.
> >>
> >> What kind of support do you mean? io_uring is asynchronous in nature
> >> with all intrinsic tracing/debugging/etc. problems of such APIs.
> >> And there are a lot of handy trace points, are those not enough?
> >>
> >> Though, this can be an interesting project to rethink how async
> >> APIs are worked with.
> >
> > Yeah, it's an interesting problem. The uring has the same events, as
> > far as I understand, that are recorded in a multithreaded strace
> > output (syscall entry, syscall exit); nothing more is needed>
> > I do think this needs to be integrated into strace(1), otherwise the
> > usefulness of that tool (which I think is *very* high) would go down
> > drastically as io_uring usage goes up.
>
> Not touching the topic of usefulness of strace + io_uring, but I'd rather
> have a tool that solves a problem, than a problem that created and honed
> for a tool.
Sorry, I'm not getting the metaphor. Can you please elaborate?
Thanks,
Miklos
next prev parent reply other threads:[~2020-07-15 8:41 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-05 2:06 [PATCH 0/3] readfile(2): a new syscall to make open/read/close faster Jan Ziak
2020-07-05 2:16 ` Matthew Wilcox
2020-07-05 2:46 ` Jan Ziak
2020-07-05 3:12 ` Matthew Wilcox
2020-07-05 3:18 ` Jan Ziak
2020-07-05 3:27 ` Matthew Wilcox
2020-07-05 4:09 ` Jan Ziak
2020-07-05 11:58 ` Greg KH
2020-07-06 6:07 ` Jan Ziak
2020-07-06 11:11 ` Matthew Wilcox
2020-07-06 11:18 ` Greg KH
2020-07-05 8:07 ` Vito Caputo
2020-07-05 11:44 ` Greg KH
2020-07-05 20:34 ` Vito Caputo
2020-07-05 6:32 ` Andreas Dilger
2020-07-05 7:25 ` Jan Ziak
2020-07-05 12:00 ` Greg KH
2020-07-05 11:50 ` Greg KH
2020-07-14 6:51 ` Pavel Machek
2020-07-14 8:07 ` Miklos Szeredi
2020-07-14 11:34 ` Pavel Begunkov
2020-07-14 11:55 ` Miklos Szeredi
2020-07-15 8:31 ` Pavel Begunkov
2020-07-15 8:41 ` Miklos Szeredi [this message]
2020-07-15 8:49 ` Pavel Begunkov
2020-07-15 9:00 ` Pavel Begunkov
2020-07-15 11:17 ` Miklos Szeredi
-- strict thread matches above, loose matches on Subject: below --
2020-07-04 14:02 Greg Kroah-Hartman
2020-07-04 19:30 ` Al Viro
2020-07-05 11:47 ` Greg Kroah-Hartman
2020-07-06 17:25 ` Dave Martin
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