From: Maxime Devos <maximedevos@telenet.be>
To: "Ludovic Courtès" <ludo@gnu.org>
Cc: 58035@debbugs.gnu.org
Subject: [bug#58035] sync-before-registering is false, possibly the cause of empty files in the store
Date: Wed, 5 Oct 2022 09:58:18 +0200 [thread overview]
Message-ID: <d5501c08-2972-c12f-ea06-f1320c84aba4@telenet.be> (raw)
In-Reply-To: <87zgebs1h5.fsf@gnu.org>
[-- Attachment #1.1.1: Type: text/plain, Size: 1251 bytes --]
On 04-10-2022 23:49, Ludovic Courtès wrote:
> Hi,
>
> Maxime Devos <maximedevos@telenet.be> skribis:
>
>> 'sync' seems relatively inexpensive to me, compared to the time
>> required for building a package and even more inexpensive compared to
>> the cost of debugging store corruption:
>
> That’s not a fair comparison. :-)
Possibly, openjdk is a bit of an extreme case.
> Imagine, you run reconfigure/upgrade;
> that downloads tens to hundreds of store items. Calling sync(2) after
> each item may be hardly noticeably on an SSD, but I bet it’s going to be
> super expensive on an HDD. (In the syslogd case, each fsync(2) call—not
> even sync(2)—would cause pauses of several 100s of ms.)
If after some testing, this turns out to be a problem, there are some
options to avoid this (see: the delaying 'fsync' of the previous response).
> Maybe a good test would be to run a daemon on an “average” HDD with
> sync-before-registering = true and to run ‘perf timechart record’ while
> it’s fetching a large number of substitutes. That way we’d have
> concrete data to talk about.
>
> Any takers? :-)
I don't have a HDD to test sync-before-registering=true with.
Greetings,
Maxime.
[-- Attachment #1.1.2: OpenPGP public key --]
[-- Type: application/pgp-keys, Size: 929 bytes --]
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 236 bytes --]
next prev parent reply other threads:[~2022-10-05 7:59 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-24 1:35 [bug#58035] sync-before-registering is false, possibly the cause of empty files in the store Maxime Devos
2022-10-04 7:52 ` Ludovic Courtès
2022-10-04 14:04 ` Maxime Devos
2022-10-04 21:49 ` Ludovic Courtès
2022-10-05 7:58 ` Maxime Devos [this message]
2022-10-05 11:54 ` zimoun
2022-10-07 9:44 ` Ludovic Courtès
2022-10-17 18:03 ` zimoun
2022-10-17 18:51 ` Maxime Devos
2022-10-18 15:34 ` Ludovic Courtès
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
List information: https://guix.gnu.org/
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=d5501c08-2972-c12f-ea06-f1320c84aba4@telenet.be \
--to=maximedevos@telenet.be \
--cc=58035@debbugs.gnu.org \
--cc=ludo@gnu.org \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://git.savannah.gnu.org/cgit/guix.git
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 read-only IMAP folder(s) and NNTP newsgroup(s).