Linux-Fsdevel Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Pavel Begunkov <asml.silence@gmail.com>
To: Miklos Szeredi <miklos@szeredi.hu>
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 11:49:36 +0300	[thread overview]
Message-ID: <b3adac43-f4ec-7820-1297-59eee206f308@gmail.com> (raw)
In-Reply-To: <CAJfpegvkw5Exptz=gY5bRy2U8GjvTo+muBHsgdF_PA5=hyhmSA@mail.gmail.com>

On 15/07/2020 11:41, Miklos Szeredi wrote:
> 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?

Sure, I mean _if_ there are tools that conceptually suit better, I'd
prefer to work with them, then trying to shove a new and possibly alien
infrastructure into strace.

But my knowledge of strace is very limited, so can't tell whether that's
the case. E.g. can it utilise static trace points?

-- 
Pavel Begunkov

  reply	other threads:[~2020-07-15  8:51 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-05  2:06 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
2020-07-15  8:49               ` Pavel Begunkov [this message]
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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=b3adac43-f4ec-7820-1297-59eee206f308@gmail.com \
    --to=asml.silence@gmail.com \
    --cc=0xe2.0x9a.0x9b@gmail.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=io-uring@vger.kernel.org \
    --cc=linux-api@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-kselftest@vger.kernel.org \
    --cc=linux-man@vger.kernel.org \
    --cc=miklos@szeredi.hu \
    --cc=mtk.manpages@gmail.com \
    --cc=pavel@denx.de \
    --cc=shuah@kernel.org \
    --cc=viro@zeniv.linux.org.uk \
    --subject='Re: [PATCH 0/3] readfile(2): a new syscall to make open/read/close faster' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).