public inbox for libc-alpha@sourceware.org
 help / color / mirror / Atom feed
From: Daniel Black <daniel@mariadb.org>
To: libc-alpha@sourceware.org
Subject: ld.so - text and .data application segments to huge pages
Date: Thu, 4 Feb 2021 18:58:34 +1100	[thread overview]
Message-ID: <CABVffEMvuFXUcZBcDs8GQM=CttHeZcV-=0nDJ022pH5KQy4Nzg@mail.gmail.com> (raw)

Hi,

I received this exceptionally large (slightly convoluted) patch to
MariaDB to move the .text and .data sections to huge pages in the
MariaDB issue https://jira.mariadb.org/browse/MDEV-24051.

The author Dmitriy Philimonov (Huawei) claimed great gains of "9% in
TPS speedup. iTLB && dTLB misses reduced in 38 times and 5 times
respectively. Latency becomes lower, the jitter in the TPS reduced
significantly", so it's definitely beneficial.

Obviously maintaining such a large loader work around in a userspace
application is going to be a burden on the skill set of developers we
have available.

How complex would it be for the glibc elf loader to use huge pages for
data segments on load? (extending _dl_map_segments with an environment
variable control like LD_HUGEPAGES I assume).

Is there any required kernel work to implement this feature?

Would such a concept be supported by the developer community here?

If so I'm happy to write up a feature request (https://sourceware.org/bugzilla).

Anyone off hand interested in writing it?

Cheers,

Daniel
MariaDB Foundation

             reply	other threads:[~2021-02-04  7:58 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-04  7:58 Daniel Black [this message]
2021-02-04 10:28 ` Florian Weimer
2021-02-11  7:53   ` Daniel Black

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

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CABVffEMvuFXUcZBcDs8GQM=CttHeZcV-=0nDJ022pH5KQy4Nzg@mail.gmail.com' \
    --to=daniel@mariadb.org \
    --cc=libc-alpha@sourceware.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.
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).