From: Anna Schumaker <Anna.Schumaker@netapp.com>
To: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>,
Andreas Dilger <adilger@dilger.ca>, <linux-nfs@vger.kernel.org>,
<linux-btrfs@vger.kernel.org>, <linux-fsdevel@vger.kernel.org>,
<linux-api@vger.kernel.org>, <zab@zabbo.net>, <clm@fb.com>,
<mtk.manpages@gmail.com>, <andros@netapp.com>,
<hch@infradead.org>
Subject: Re: [PATCH v1 0/8] VFS: In-kernel copy system call
Date: Tue, 8 Sep 2015 16:49:15 -0400 [thread overview]
Message-ID: <55EF49CB.3030405@Netapp.com> (raw)
In-Reply-To: <20150908204517.GC30681@birch.djwong.org>
On 09/08/2015 04:45 PM, Darrick J. Wong wrote:
> On Tue, Sep 08, 2015 at 11:08:03AM -0400, Anna Schumaker wrote:
>> On 09/05/2015 04:33 AM, Al Viro wrote:
>>> On Fri, Sep 04, 2015 at 04:25:27PM -0600, Andreas Dilger wrote:
>>>
>>>> This is a bit of a surprising result, since in my testing in the
>>>> past, copy_{to/from}_user() is a major consumer of CPU time (50%
>>>> of a CPU core at 1GB/s). What backing filesystem did you test on?
>>>
>>> While we are at it, was cp(1) using read(2)/write(2) loop or was it using
>>> something else (sendfile(2), for example)?
>>
>> cp uses a read / write loop, and has some heuristics for guessing an optimum buffer size.
>
> ..but afaict cp doesn't fsync at the end, which means it's possible that
> the destination file's blocks are still delalloc and nothing's been flushed
> to disk yet. What happens if you time (cp /tmp/a /tmp/b ; sync) ?
That's already how I was using cp :). The example program in my man page also doesn't fsync at the end, so the extra sync at the end is needed for both.
Anna
>
> 2048M / 1.667s = ~1200MB/s.
>
> --D
>
>>
>> Anna
>>
>>>
>>
WARNING: multiple messages have this Message-ID (diff)
From: Anna Schumaker <Anna.Schumaker-HgOvQuBEEgTQT0dZR+AlfA@public.gmane.org>
To: "Darrick J. Wong" <darrick.wong-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
Cc: Al Viro <viro-3bDd1+5oDREiFSDQTTA3OLVCufUGDwFn@public.gmane.org>,
Andreas Dilger <adilger-m1MBpc4rdrD3fQ9qLvQP4Q@public.gmane.org>,
<linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
<linux-btrfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
<linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
<linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
<zab-ugsP4Wv/S6ZeoWH0uzbU5w@public.gmane.org>,
<clm-b10kYP2dOMg@public.gmane.org>,
<mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
<andros-HgOvQuBEEgTQT0dZR+AlfA@public.gmane.org>,
<hch-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
Subject: Re: [PATCH v1 0/8] VFS: In-kernel copy system call
Date: Tue, 8 Sep 2015 16:49:15 -0400 [thread overview]
Message-ID: <55EF49CB.3030405@Netapp.com> (raw)
In-Reply-To: <20150908204517.GC30681-PTl6brltDGh4DFYR7WNSRA@public.gmane.org>
On 09/08/2015 04:45 PM, Darrick J. Wong wrote:
> On Tue, Sep 08, 2015 at 11:08:03AM -0400, Anna Schumaker wrote:
>> On 09/05/2015 04:33 AM, Al Viro wrote:
>>> On Fri, Sep 04, 2015 at 04:25:27PM -0600, Andreas Dilger wrote:
>>>
>>>> This is a bit of a surprising result, since in my testing in the
>>>> past, copy_{to/from}_user() is a major consumer of CPU time (50%
>>>> of a CPU core at 1GB/s). What backing filesystem did you test on?
>>>
>>> While we are at it, was cp(1) using read(2)/write(2) loop or was it using
>>> something else (sendfile(2), for example)?
>>
>> cp uses a read / write loop, and has some heuristics for guessing an optimum buffer size.
>
> ..but afaict cp doesn't fsync at the end, which means it's possible that
> the destination file's blocks are still delalloc and nothing's been flushed
> to disk yet. What happens if you time (cp /tmp/a /tmp/b ; sync) ?
That's already how I was using cp :). The example program in my man page also doesn't fsync at the end, so the extra sync at the end is needed for both.
Anna
>
> 2048M / 1.667s = ~1200MB/s.
>
> --D
>
>>
>> Anna
>>
>>>
>>
--
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WARNING: multiple messages have this Message-ID (diff)
From: Anna Schumaker <Anna.Schumaker-HgOvQuBEEgTQT0dZR+AlfA@public.gmane.org>
To: "Darrick J. Wong" <darrick.wong-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
Cc: Al Viro <viro-3bDd1+5oDREiFSDQTTA3OLVCufUGDwFn@public.gmane.org>,
Andreas Dilger <adilger-m1MBpc4rdrD3fQ9qLvQP4Q@public.gmane.org>,
linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-btrfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
zab-ugsP4Wv/S6ZeoWH0uzbU5w@public.gmane.org,
clm-b10kYP2dOMg@public.gmane.org,
mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org,
andros-HgOvQuBEEgTQT0dZR+AlfA@public.gmane.org,
hch-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org
Subject: Re: [PATCH v1 0/8] VFS: In-kernel copy system call
Date: Tue, 8 Sep 2015 16:49:15 -0400 [thread overview]
Message-ID: <55EF49CB.3030405@Netapp.com> (raw)
In-Reply-To: <20150908204517.GC30681-PTl6brltDGh4DFYR7WNSRA@public.gmane.org>
On 09/08/2015 04:45 PM, Darrick J. Wong wrote:
> On Tue, Sep 08, 2015 at 11:08:03AM -0400, Anna Schumaker wrote:
>> On 09/05/2015 04:33 AM, Al Viro wrote:
>>> On Fri, Sep 04, 2015 at 04:25:27PM -0600, Andreas Dilger wrote:
>>>
>>>> This is a bit of a surprising result, since in my testing in the
>>>> past, copy_{to/from}_user() is a major consumer of CPU time (50%
>>>> of a CPU core at 1GB/s). What backing filesystem did you test on?
>>>
>>> While we are at it, was cp(1) using read(2)/write(2) loop or was it using
>>> something else (sendfile(2), for example)?
>>
>> cp uses a read / write loop, and has some heuristics for guessing an optimum buffer size.
>
> ..but afaict cp doesn't fsync at the end, which means it's possible that
> the destination file's blocks are still delalloc and nothing's been flushed
> to disk yet. What happens if you time (cp /tmp/a /tmp/b ; sync) ?
That's already how I was using cp :). The example program in my man page also doesn't fsync at the end, so the extra sync at the end is needed for both.
Anna
>
> 2048M / 1.667s = ~1200MB/s.
>
> --D
>
>>
>> Anna
>>
>>>
>>
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
next prev parent reply other threads:[~2015-09-08 20:49 UTC|newest]
Thread overview: 121+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-04 20:16 [PATCH v1 0/8] VFS: In-kernel copy system call Anna Schumaker
2015-09-04 20:16 ` Anna Schumaker
2015-09-04 20:16 ` Anna Schumaker
2015-09-04 20:16 ` [PATCH v1 1/9] vfs: add copy_file_range syscall and vfs helper Anna Schumaker
2015-09-04 20:16 ` Anna Schumaker
2015-09-04 20:16 ` Anna Schumaker
2015-09-04 21:50 ` Darrick J. Wong
2015-09-04 20:16 ` [PATCH v1 2/8] x86: add sys_copy_file_range to syscall tables Anna Schumaker
2015-09-04 20:16 ` Anna Schumaker
2015-09-04 20:16 ` [PATCH v1 3/8] btrfs: add .copy_file_range file operation Anna Schumaker
2015-09-04 20:16 ` Anna Schumaker
2015-09-04 21:02 ` Josef Bacik
2015-09-04 21:02 ` Josef Bacik
2015-09-04 21:02 ` Josef Bacik
2015-09-09 8:39 ` David Sterba
2015-09-04 20:16 ` [PATCH v1 4/8] btrfs: Add mountpoint checking during btrfs_copy_file_range Anna Schumaker
2015-09-04 20:16 ` Anna Schumaker
2015-09-04 20:16 ` Anna Schumaker
2015-09-09 9:18 ` David Sterba
2015-09-09 15:56 ` Anna Schumaker
2015-09-09 15:56 ` Anna Schumaker
2015-09-04 20:16 ` [PATCH v1 5/8] vfs: Remove copy_file_range mountpoint checks Anna Schumaker
2015-09-04 20:16 ` Anna Schumaker
2015-09-04 20:16 ` Anna Schumaker
2015-09-04 20:17 ` [PATCH v1 6/8] vfs: Copy should check len after file open mode Anna Schumaker
2015-09-04 20:17 ` Anna Schumaker
2015-09-04 20:17 ` Anna Schumaker
2015-09-04 20:17 ` [PATCH v1 7/8] vfs: Copy should use file_out rather than file_in Anna Schumaker
2015-09-04 20:17 ` Anna Schumaker
2015-09-04 20:17 ` [PATCH v1 8/8] vfs: Fall back on splice if no copy function defined Anna Schumaker
2015-09-04 20:17 ` Anna Schumaker
2015-09-04 20:17 ` Anna Schumaker
2015-09-04 21:08 ` Darrick J. Wong
2015-09-08 14:57 ` Anna Schumaker
2015-09-08 14:57 ` Anna Schumaker
2015-09-08 14:57 ` Anna Schumaker
2015-09-04 20:17 ` [PATCH v1 9/8] copy_file_range.2: New page documenting copy_file_range() Anna Schumaker
2015-09-04 20:17 ` Anna Schumaker
2015-09-04 20:17 ` Anna Schumaker
2015-09-04 21:38 ` Darrick J. Wong
2015-09-04 22:31 ` Andreas Dilger
2015-09-04 22:31 ` Andreas Dilger
2015-09-08 15:05 ` Anna Schumaker
2015-09-08 15:05 ` Anna Schumaker
2015-09-08 15:05 ` Anna Schumaker
2015-09-08 15:04 ` Anna Schumaker
2015-09-08 15:04 ` Anna Schumaker
2015-09-08 15:04 ` Anna Schumaker
2015-09-08 20:39 ` Darrick J. Wong
2015-09-09 9:16 ` David Sterba
2015-09-09 11:38 ` Austin S Hemmelgarn
2015-09-09 11:38 ` Austin S Hemmelgarn
2015-09-09 17:17 ` Darrick J. Wong
2015-09-09 17:31 ` Anna Schumaker
2015-09-09 17:31 ` Anna Schumaker
2015-09-09 17:31 ` Anna Schumaker
2015-09-09 18:12 ` Darrick J. Wong
2015-09-09 18:12 ` Darrick J. Wong
2015-09-09 19:25 ` Anna Schumaker
2015-09-09 19:25 ` Anna Schumaker
2015-09-10 15:42 ` David Sterba
2015-09-10 15:42 ` David Sterba
2015-09-10 16:43 ` Darrick J. Wong
2015-09-10 16:43 ` Darrick J. Wong
2015-09-04 22:25 ` [PATCH v1 0/8] VFS: In-kernel copy system call Andreas Dilger
2015-09-04 22:25 ` Andreas Dilger
2015-09-05 8:33 ` Al Viro
2015-09-05 8:33 ` Al Viro
2015-09-08 15:08 ` Anna Schumaker
2015-09-08 15:08 ` Anna Schumaker
2015-09-08 15:08 ` Anna Schumaker
2015-09-08 20:45 ` Darrick J. Wong
2015-09-08 20:49 ` Anna Schumaker [this message]
2015-09-08 20:49 ` Anna Schumaker
2015-09-08 20:49 ` Anna Schumaker
2015-09-08 15:07 ` Anna Schumaker
2015-09-08 15:07 ` Anna Schumaker
2015-09-08 15:21 ` Pádraig Brady
2015-09-08 15:21 ` Pádraig Brady
2015-09-08 18:23 ` Anna Schumaker
2015-09-08 18:23 ` Anna Schumaker
2015-09-08 19:10 ` Andy Lutomirski
2015-09-08 19:10 ` Andy Lutomirski
2015-09-08 20:03 ` Pádraig Brady
2015-09-08 20:03 ` Pádraig Brady
2015-09-08 21:29 ` Darrick J. Wong
2015-09-08 21:29 ` Darrick J. Wong
2015-09-08 21:45 ` Andy Lutomirski
2015-09-08 21:45 ` Andy Lutomirski
2015-09-08 22:39 ` Darrick J. Wong
2015-09-08 22:39 ` Darrick J. Wong
2015-09-08 23:08 ` Andy Lutomirski
2015-09-08 23:08 ` Andy Lutomirski
2015-09-09 1:19 ` Darrick J. Wong
2015-09-09 1:19 ` Darrick J. Wong
2015-09-09 20:09 ` Chris Mason
2015-09-09 20:26 ` Trond Myklebust
2015-09-09 20:26 ` Trond Myklebust
2015-09-09 20:38 ` Chris Mason
2015-09-09 20:38 ` Chris Mason
2015-09-09 20:41 ` Anna Schumaker
2015-09-09 20:41 ` Anna Schumaker
2015-09-09 21:42 ` Darrick J. Wong
2015-09-09 21:42 ` Darrick J. Wong
2015-09-09 20:37 ` Andy Lutomirski
2015-09-09 20:37 ` Andy Lutomirski
2015-09-09 20:42 ` Chris Mason
2015-09-09 20:42 ` Chris Mason
2015-09-13 23:25 ` Dave Chinner
2015-09-13 23:25 ` Dave Chinner
2015-09-14 17:53 ` Andy Lutomirski
2015-09-14 17:53 ` Andy Lutomirski
2015-09-09 18:52 ` Anna Schumaker
2015-09-09 18:52 ` Anna Schumaker
2015-09-09 21:16 ` Darrick J. Wong
2015-09-09 21:16 ` Darrick J. Wong
2015-09-10 15:10 ` Anna Schumaker
2015-09-10 15:10 ` Anna Schumaker
2015-09-10 15:49 ` Austin S Hemmelgarn
2015-09-10 15:49 ` Austin S Hemmelgarn
2015-09-10 11:40 ` Austin S Hemmelgarn
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