linux-kernel - Re: [PATCH] FUSE: Improve aio directIO write performance for size extending writes.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAOiN93kqSU9bBVa6_oiqkmBv=W11xz1a0pAig_XJmE556OPYBg@mail.gmail.com>
Date:	Mon, 20 Jun 2016 12:20:02 +0530
From:	Ashish Sangwan <ashishsangwan2@...il.com>
To:	Miklos Szeredi <miklos@...redi.hu>
Cc:	linux-fsdevel <linux-fsdevel@...r.kernel.org>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] FUSE: Improve aio directIO write performance for size
 extending writes.

On Thu, Jun 16, 2016 at 4:55 PM, Miklos Szeredi <miklos@...redi.hu> wrote:
> On Thu, Apr 7, 2016 at 1:48 PM, Ashish Sangwan <ashishsangwan2@...il.com> wrote:
>> While sending the blocking directIO in fuse, the write request is broken
>> into sub-requests, each of default size 128k and all the requests are sent
>> in non-blocking background mode if async_dio mode is supported by libfuse.
>> The process which issue the write wait for the completion of all the
>> sub-requests. Sending multiple requests parallely gives a chance to perform
>> parallel writes in the user space fuse implementation if it is
>> multi-threaded and hence improves the performance.
>>
>> When there is a size extending aio dio write, we switch to
>> blocking mode so that we can properly update the size of the file after
>> completion of the writes. However, in this situation all the sub-requests
>> are sent in serialized manner where the next request is sent only after
>> receiving the reply of the current request. Hence the multi-threaded user
>> space implementation is not utilized properly.
>>
>> This patch changes the size extending aio dio behavior to exactly follow
>> blocking dio. For multi threaded fuse implementation having 10 threads and
>> using buffer size of 64MB to perform async directIO, we are getting double
>> the speed.
>>
>> Signed-off-by: Ashish Sangwan <ashishsangwan2@...il.com>
>
> Thanks for you patience.  Pushed to
>
>   git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse.git for-next
>
> I simplified the logic, please verify that I didn't mess something up.

The change looks ok.

>
> Thanks,
> Miklos