public inbox for libc-alpha@sourceware.org
 help / color / mirror / Atom feed
From: "H.J. Lu" <hjl.tools@gmail.com>
To: DJ Delorie <dj@redhat.com>
Cc: GNU C Library <libc-alpha@sourceware.org>
Subject: Re: tunables vs osxsave vs checkpointing vs _dl_runtime_resolve
Date: Thu, 18 Mar 2021 13:39:45 -0700	[thread overview]
Message-ID: <CAMe9rOpt3bMgyQGmk6Of1cA83-9FOg0jMK=Q13oH6NBGHD_FQg@mail.gmail.com> (raw)
In-Reply-To: <xn5z1onynz.fsf@rhel8.vm>

On Thu, Mar 18, 2021 at 10:45 AM DJ Delorie <dj@redhat.com> wrote:
>
>
> "H.J. Lu" <hjl.tools@gmail.com> writes:
> > Please open a glibc bug and CC me.
>
> https://sourceware.org/bugzilla/show_bug.cgi?id=27605
>

GLIBC_TUNABLES=glibc.cpu.hwcaps=-XSAVEC can be used to control it:

(gdb) r --direct
Starting program:
/export/build/gnu/tools-build/glibc-cet-gitlab/build-x86_64-linux/elf/tst-x86_64-1
--direct
[Inferior 1 (process 1499934) exited normally]
(gdb) b _dl_runtime_resolve_xsave
Breakpoint 1 at 0x7ffff7fe19d0: file ../sysdeps/x86_64/dl-trampoline.h, line 67.
(gdb) b _dl_runtime_resolve_xsavec
Breakpoint 2 at 0x7ffff7fe1aa0: file ../sysdeps/x86_64/dl-trampoline.h, line 67.
(gdb) r
Starting program:
/export/build/gnu/tools-build/glibc-cet-gitlab/build-x86_64-linux/elf/tst-x86_64-1
--direct

Breakpoint 2, _dl_runtime_resolve_xsavec ()
    at ../sysdeps/x86_64/dl-trampoline.h:67
67 _CET_ENDBR
(gdb) set env GLIBC_TUNABLES=glibc.cpu.hwcaps=-XSAVEC
(gdb) r
The program being debugged has been started already.
Start it from the beginning? (y or n) y
Starting program:
/export/build/gnu/tools-build/glibc-cet-gitlab/build-x86_64-linux/elf/tst-x86_64-1
--direct

Breakpoint 1, _dl_runtime_resolve_xsave ()
    at ../sysdeps/x86_64/dl-trampoline.h:67
67 _CET_ENDBR
(gdb)

-- 
H.J.

  reply	other threads:[~2021-03-18 20:40 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-18 17:18 DJ Delorie
2021-03-18 17:29 ` H.J. Lu
2021-03-18 17:45   ` DJ Delorie
2021-03-18 20:39     ` H.J. Lu [this message]
2021-03-19  3:40       ` DJ Delorie
2021-03-19  4:16         ` H.J. Lu
2021-03-19  4:35           ` DJ Delorie
2021-03-18 17:32 ` Florian Weimer
2021-03-18 17:47   ` DJ Delorie
2021-03-18 17:57     ` Florian Weimer
2021-03-18 18:19       ` DJ Delorie
2021-03-19 16:43 ` Szabolcs Nagy
2021-03-19 21:12   ` DJ Delorie

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='CAMe9rOpt3bMgyQGmk6Of1cA83-9FOg0jMK=Q13oH6NBGHD_FQg@mail.gmail.com' \
    --to=hjl.tools@gmail.com \
    --cc=dj@redhat.com \
    --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).