From: Andy Wingo <wingo@pobox.com>
To: ludo@gnu.org (Ludovic Courtès)
Cc: 19540-done@debbugs.gnu.org, Matt Wette <mwette@alumni.caltech.edu>
Subject: bug#19540: repeated ./././ in compiled modules
Date: Fri, 24 Jun 2016 10:49:12 +0200 [thread overview]
Message-ID: <87fus3geev.fsf@pobox.com> (raw)
In-Reply-To: <87twgj9eiu.fsf@gnu.org> ("Ludovic Courtès"'s message of "Fri, 24 Jun 2016 10:28:41 +0200")
Hi :)
On Fri 24 Jun 2016 10:28, ludo@gnu.org (Ludovic Courtès) writes:
> Hello!
>
> Andy Wingo <wingo@pobox.com> skribis:
>
>> On Thu 23 Jun 2016 15:06, ludo@gnu.org (Ludovic Courtès) writes:
>>
>>> ‘canonicalize_file_name’ is costly: roughly one syscall per file name
>>> component.
>>>
>>> IIUC, ‘canonicalize_file_name’ is now called once for each ‘%load-path’
>>> entry and file name that we canonicalize. Is this correct?
>>
>> That's correct, but only for relative canonicalization, which is in
>> practive only when loading Scheme files from source. Seems out of the
>> hot path; what do you think?
>
> I think it’s likely to have a noticeable impact on startup time for
> projects with a large number of modules like Guix.
Aren't they usually compiled? Loading compiled files will not
go through this path AFAIU.
> For instance, commands like ‘guix package -A’ or ‘guix build foo’ load
> all the modules. The impact will be smaller on a laptop with an SSD
> than on an NFS mount, where it’s likely going to be terrrible (this
> could be tested using the ‘delay’ device mapper.)
Oh I'm with you that we need to be careful here. I am under the
impression though that there's no additional impact here because this is
just something that happens at compile-time. Or if you load a source
file, but in that case you're evaluating and expecting a perf loss is
not the end of the world.
Andy
next prev parent reply other threads:[~2016-06-24 8:49 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-09 4:13 bug#19540: minor: module path picking up ./././ Matt Wette
2015-01-10 22:45 ` bug#19540: repeated ./././ in compiled modules Matt Wette
2015-01-19 20:28 ` Ludovic Courtès
2015-01-19 22:19 ` Matt Wette
2015-01-20 21:12 ` Ludovic Courtès
2016-06-23 8:36 ` Andy Wingo
2016-06-23 13:06 ` Ludovic Courtès
2016-06-23 16:03 ` Andy Wingo
2016-06-24 8:28 ` Ludovic Courtès
2016-06-24 8:49 ` Andy Wingo [this message]
2016-06-24 9:41 ` Ludovic Courtès
2015-01-18 16:09 ` bug#19540: also generates problem for debugger tracebacks Matt Wette
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://www.gnu.org/software/guile/
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=87fus3geev.fsf@pobox.com \
--to=wingo@pobox.com \
--cc=19540-done@debbugs.gnu.org \
--cc=ludo@gnu.org \
--cc=mwette@alumni.caltech.edu \
/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.
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).