From: Jonathan Wakely <jwakely@redhat.com>
To: "Jannik Glückert" <jannik.glueckert@gmail.com>
Cc: libstdc++@gcc.gnu.org, gcc-patches@gcc.gnu.org
Subject: Re: [PATCH v2 1/2] libstdc++: also use sendfile for big files
Date: Mon, 20 Mar 2023 22:30:24 +0000 [thread overview]
Message-ID: <ZBjegJuddjPghBd2@redhat.com> (raw)
In-Reply-To: <ZBjd1OEyzE7NWogi@redhat.com>
On 20/03/23 22:27 +0000, Jonathan Wakely wrote:
>On 06/03/23 20:52 +0100, Jannik Glückert wrote:
>>we were previously only using sendfile for files smaller than 2GB, as
>>sendfile needs to be called repeatedly for files bigger than that.
>>
>>some quick numbers, copying a 16GB file, average of 10 repetitions:
>> old:
>> real: 13.4s
>> user: 0.14s
>> sys : 7.43s
>> new:
>> real: 8.90s
>> user: 0.00s
>> sys : 3.68s
>>
>>Additionally, this fixes
>>https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108178
>>
>>libstdc++-v3/ChangeLog:
>>
>> * acinclude.m4 (_GLIBCXX_HAVE_LSEEK): define
>> * config.h.in: Regenerate.
>> * configure: Regenerate.
>> * src/filesystem/ops-common.h: enable sendfile for files
>> >2GB in std::filesystem::copy_file, skip zero-length files
Also, the ChangeLog entry needs to be indented with tabs, name the
changed functions, and should be complete sentences, e.g.
* acinclude.m4 (_GLIBCXX_HAVE_LSEEK): Define.
* config.h.in: Regenerate.
* configure: Regenerate.
* src/filesystem/ops-common.h (copy_file_sendfile): Define new
function for sendfile logic. Loop to support large files. Skip
zero-length files.
(do_copy_file): Use it.
next prev parent reply other threads:[~2023-03-20 22:30 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-15 19:29 [PATCH v2 1/2] libstdc++: use copy_file_range, improve sendfile in filesystem::copy_file Jannik Glückert
2023-03-20 15:16 ` Jonathan Wakely
2023-03-20 15:18 ` Jonathan Wakely
2023-03-20 22:27 ` [PATCH v2 1/2] libstdc++: also use sendfile for big files Jonathan Wakely
2023-03-20 22:30 ` Jonathan Wakely [this message]
2023-03-22 12:14 ` Jonathan Wakely
2023-03-22 12:18 ` Jonathan Wakely
2023-03-22 12:20 ` Jonathan Wakely
2023-06-06 11:37 ` Jonathan Wakely
2023-06-06 11:36 ` Jonathan Wakely
2023-06-06 11:35 ` Jonathan Wakely
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