* [Bug nptl/16630] Use SYSENTER for pthread_cond_broadcast/signal() (i.e. fix "FIXME: Ingo" issue)
2014-02-24 22:41 [Bug nptl/16630] New: Use SYSENTER for pthread_cond_broadcast/signal() (i.e. fix "FIXME: Ingo" issue) cjones.bugs at gmail dot com
@ 2014-02-25 2:04 ` bugdal at aerifal dot cx
2014-02-25 4:51 ` cjones.bugs at gmail dot com
` (8 subsequent siblings)
9 siblings, 0 replies; 12+ messages in thread
From: bugdal at aerifal dot cx @ 2014-02-25 2:04 UTC (permalink / raw)
To: glibc-bugs
https://sourceware.org/bugzilla/show_bug.cgi?id=16630
Rich Felker <bugdal at aerifal dot cx> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |bugdal at aerifal dot cx
--- Comment #1 from Rich Felker <bugdal at aerifal dot cx> ---
Ideally this asm will be removed at some point; I think that would resolve this
issue automatically.
BTW, the idea of letting apps hook __kernel_vsyscall is a very bad one. In
order to fix issue #12683, use of __kernel_vsyscall needs to be abandoned for
cancellable syscalls. Treating such hooking as a supported usage would preclude
fixing a serious open bug.
--
You are receiving this mail because:
You are on the CC list for the bug.
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug nptl/16630] Use SYSENTER for pthread_cond_broadcast/signal() (i.e. fix "FIXME: Ingo" issue)
2014-02-24 22:41 [Bug nptl/16630] New: Use SYSENTER for pthread_cond_broadcast/signal() (i.e. fix "FIXME: Ingo" issue) cjones.bugs at gmail dot com
2014-02-25 2:04 ` [Bug nptl/16630] " bugdal at aerifal dot cx
@ 2014-02-25 4:51 ` cjones.bugs at gmail dot com
2014-02-25 5:47 ` bugdal at aerifal dot cx
` (7 subsequent siblings)
9 siblings, 0 replies; 12+ messages in thread
From: cjones.bugs at gmail dot com @ 2014-02-25 4:51 UTC (permalink / raw)
To: glibc-bugs
https://sourceware.org/bugzilla/show_bug.cgi?id=16630
--- Comment #2 from Chris Jones <cjones.bugs at gmail dot com> ---
(In reply to Rich Felker from comment #1)
> Ideally this asm will be removed at some point; I think that would resolve
> this issue automatically.
Do you happen to know if that's filed already? I'm curious what it would be
replaced with.
>
> BTW, the idea of letting apps hook __kernel_vsyscall is a very bad one. In
> order to fix issue #12683, use of __kernel_vsyscall needs to be abandoned
> for cancellable syscalls. Treating such hooking as a supported usage would
> preclude fixing a serious open bug.
Oh, please don't let me give you the wrong idea; I'm not at all advocating for
official support of hooking __kernel_vsyscall. What I do with
__kernel_vsyscall stays in the privacy of my home ;). (Trust me, I don't want
to be touching it either.) But please take this patch at face value.
--
You are receiving this mail because:
You are on the CC list for the bug.
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug nptl/16630] Use SYSENTER for pthread_cond_broadcast/signal() (i.e. fix "FIXME: Ingo" issue)
2014-02-24 22:41 [Bug nptl/16630] New: Use SYSENTER for pthread_cond_broadcast/signal() (i.e. fix "FIXME: Ingo" issue) cjones.bugs at gmail dot com
2014-02-25 2:04 ` [Bug nptl/16630] " bugdal at aerifal dot cx
2014-02-25 4:51 ` cjones.bugs at gmail dot com
@ 2014-02-25 5:47 ` bugdal at aerifal dot cx
2014-02-25 16:11 ` Ondřej Bílka
2014-02-25 7:41 ` cjones.bugs at gmail dot com
` (6 subsequent siblings)
9 siblings, 1 reply; 12+ messages in thread
From: bugdal at aerifal dot cx @ 2014-02-25 5:47 UTC (permalink / raw)
To: glibc-bugs
http://sourceware.org/bugzilla/show_bug.cgi?id=16630
--- Comment #3 from Rich Felker <bugdal at aerifal dot cx> ---
On Tue, Feb 25, 2014 at 04:51:18AM +0000, cjones.bugs at gmail dot com wrote:
> Do you happen to know if that's filed already? I'm curious what it would be
> replaced with.
There is portable C code for all of these functions already and a
strong sentiment from some users and developers that the asm is
unnecessary, error-prone, and lags behind the C in getting fixes and
improvements. See the related thread on the libc-alpha mailing list:
[RFC][BZ #16549, #16410] Remove pthread_(cond)wait assembly implementations?
Basically I think if it could be demonstrated that the C performs just
as well (or within a margin of difference that's not significant), the
asm could be removed.
--
You are receiving this mail because:
You are on the CC list for the bug.
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [Bug nptl/16630] Use SYSENTER for pthread_cond_broadcast/signal() (i.e. fix "FIXME: Ingo" issue)
2014-02-25 5:47 ` bugdal at aerifal dot cx
@ 2014-02-25 16:11 ` Ondřej Bílka
0 siblings, 0 replies; 12+ messages in thread
From: Ondřej Bílka @ 2014-02-25 16:11 UTC (permalink / raw)
To: bugdal at aerifal dot cx; +Cc: glibc-bugs
On Tue, Feb 25, 2014 at 05:47:16AM +0000, bugdal at aerifal dot cx wrote:
> http://sourceware.org/bugzilla/show_bug.cgi?id=16630
>
> --- Comment #3 from Rich Felker <bugdal at aerifal dot cx> ---
> On Tue, Feb 25, 2014 at 04:51:18AM +0000, cjones.bugs at gmail dot com wrote:
> > Do you happen to know if that's filed already? I'm curious what it would be
> > replaced with.
>
> There is portable C code for all of these functions already and a
> strong sentiment from some users and developers that the asm is
> unnecessary, error-prone, and lags behind the C in getting fixes and
> improvements. See the related thread on the libc-alpha mailing list:
>
> [RFC][BZ #16549, #16410] Remove pthread_(cond)wait assembly implementations?
>
> Basically I think if it could be demonstrated that the C performs just
> as well (or within a margin of difference that's not significant), the
> asm could be removed.
>
Actually c is around 5000 cycles faster. My guess is that its because
assembly does extra syscall which has bigger impact than
microoptimizations, I did not trace that yet.
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug nptl/16630] Use SYSENTER for pthread_cond_broadcast/signal() (i.e. fix "FIXME: Ingo" issue)
2014-02-24 22:41 [Bug nptl/16630] New: Use SYSENTER for pthread_cond_broadcast/signal() (i.e. fix "FIXME: Ingo" issue) cjones.bugs at gmail dot com
` (2 preceding siblings ...)
2014-02-25 5:47 ` bugdal at aerifal dot cx
@ 2014-02-25 7:41 ` cjones.bugs at gmail dot com
2014-02-25 16:12 ` neleai at seznam dot cz
` (5 subsequent siblings)
9 siblings, 0 replies; 12+ messages in thread
From: cjones.bugs at gmail dot com @ 2014-02-25 7:41 UTC (permalink / raw)
To: glibc-bugs
https://sourceware.org/bugzilla/show_bug.cgi?id=16630
--- Comment #4 from Chris Jones <cjones.bugs at gmail dot com> ---
I see, thanks.
How do we a arrive a decision on whether to take this trivial patch?
--
You are receiving this mail because:
You are on the CC list for the bug.
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug nptl/16630] Use SYSENTER for pthread_cond_broadcast/signal() (i.e. fix "FIXME: Ingo" issue)
2014-02-24 22:41 [Bug nptl/16630] New: Use SYSENTER for pthread_cond_broadcast/signal() (i.e. fix "FIXME: Ingo" issue) cjones.bugs at gmail dot com
` (3 preceding siblings ...)
2014-02-25 7:41 ` cjones.bugs at gmail dot com
@ 2014-02-25 16:12 ` neleai at seznam dot cz
2014-03-01 22:36 ` cjones.bugs at gmail dot com
` (4 subsequent siblings)
9 siblings, 0 replies; 12+ messages in thread
From: neleai at seznam dot cz @ 2014-02-25 16:12 UTC (permalink / raw)
To: glibc-bugs
http://sourceware.org/bugzilla/show_bug.cgi?id=16630
--- Comment #5 from Ondrej Bilka <neleai at seznam dot cz> ---
On Tue, Feb 25, 2014 at 05:47:16AM +0000, bugdal at aerifal dot cx wrote:
> http://sourceware.org/bugzilla/show_bug.cgi?id=16630
>
> --- Comment #3 from Rich Felker <bugdal at aerifal dot cx> ---
> On Tue, Feb 25, 2014 at 04:51:18AM +0000, cjones.bugs at gmail dot com wrote:
> > Do you happen to know if that's filed already? I'm curious what it would be
> > replaced with.
>
> There is portable C code for all of these functions already and a
> strong sentiment from some users and developers that the asm is
> unnecessary, error-prone, and lags behind the C in getting fixes and
> improvements. See the related thread on the libc-alpha mailing list:
>
> [RFC][BZ #16549, #16410] Remove pthread_(cond)wait assembly implementations?
>
> Basically I think if it could be demonstrated that the C performs just
> as well (or within a margin of difference that's not significant), the
> asm could be removed.
>
Actually c is around 5000 cycles faster. My guess is that its because
assembly does extra syscall which has bigger impact than
microoptimizations, I did not trace that yet.
--
You are receiving this mail because:
You are on the CC list for the bug.
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug nptl/16630] Use SYSENTER for pthread_cond_broadcast/signal() (i.e. fix "FIXME: Ingo" issue)
2014-02-24 22:41 [Bug nptl/16630] New: Use SYSENTER for pthread_cond_broadcast/signal() (i.e. fix "FIXME: Ingo" issue) cjones.bugs at gmail dot com
` (4 preceding siblings ...)
2014-02-25 16:12 ` neleai at seznam dot cz
@ 2014-03-01 22:36 ` cjones.bugs at gmail dot com
2014-03-01 23:54 ` bugdal at aerifal dot cx
` (3 subsequent siblings)
9 siblings, 0 replies; 12+ messages in thread
From: cjones.bugs at gmail dot com @ 2014-03-01 22:36 UTC (permalink / raw)
To: glibc-bugs
https://sourceware.org/bugzilla/show_bug.cgi?id=16630
--- Comment #6 from Chris Jones <cjones.bugs at gmail dot com> ---
If the maintainers of this code don't want to take this patch, please resolve
this bug WONTFIX to get it off our plates.
--
You are receiving this mail because:
You are on the CC list for the bug.
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug nptl/16630] Use SYSENTER for pthread_cond_broadcast/signal() (i.e. fix "FIXME: Ingo" issue)
2014-02-24 22:41 [Bug nptl/16630] New: Use SYSENTER for pthread_cond_broadcast/signal() (i.e. fix "FIXME: Ingo" issue) cjones.bugs at gmail dot com
` (5 preceding siblings ...)
2014-03-01 22:36 ` cjones.bugs at gmail dot com
@ 2014-03-01 23:54 ` bugdal at aerifal dot cx
2014-03-02 0:09 ` cjones.bugs at gmail dot com
` (2 subsequent siblings)
9 siblings, 0 replies; 12+ messages in thread
From: bugdal at aerifal dot cx @ 2014-03-01 23:54 UTC (permalink / raw)
To: glibc-bugs
https://sourceware.org/bugzilla/show_bug.cgi?id=16630
--- Comment #7 from Rich Felker <bugdal at aerifal dot cx> ---
Please be patient. The maintainers are in the process of evaluating whether the
asm can just be removed, in which case the bug would be FIXED, not WONTFIX.
--
You are receiving this mail because:
You are on the CC list for the bug.
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug nptl/16630] Use SYSENTER for pthread_cond_broadcast/signal() (i.e. fix "FIXME: Ingo" issue)
2014-02-24 22:41 [Bug nptl/16630] New: Use SYSENTER for pthread_cond_broadcast/signal() (i.e. fix "FIXME: Ingo" issue) cjones.bugs at gmail dot com
` (6 preceding siblings ...)
2014-03-01 23:54 ` bugdal at aerifal dot cx
@ 2014-03-02 0:09 ` cjones.bugs at gmail dot com
2014-03-02 0:13 ` bugdal at aerifal dot cx
2014-06-13 6:48 ` fweimer at redhat dot com
9 siblings, 0 replies; 12+ messages in thread
From: cjones.bugs at gmail dot com @ 2014-03-02 0:09 UTC (permalink / raw)
To: glibc-bugs
https://sourceware.org/bugzilla/show_bug.cgi?id=16630
--- Comment #8 from Chris Jones <cjones.bugs at gmail dot com> ---
I don't mean that to sound impatient, I just want to emphasize that I'd prefer
an explicit "no" through a WONTFIX than an implicit one through silence. I
hate patches that die on the vine :).
--
You are receiving this mail because:
You are on the CC list for the bug.
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug nptl/16630] Use SYSENTER for pthread_cond_broadcast/signal() (i.e. fix "FIXME: Ingo" issue)
2014-02-24 22:41 [Bug nptl/16630] New: Use SYSENTER for pthread_cond_broadcast/signal() (i.e. fix "FIXME: Ingo" issue) cjones.bugs at gmail dot com
` (7 preceding siblings ...)
2014-03-02 0:09 ` cjones.bugs at gmail dot com
@ 2014-03-02 0:13 ` bugdal at aerifal dot cx
2014-06-13 6:48 ` fweimer at redhat dot com
9 siblings, 0 replies; 12+ messages in thread
From: bugdal at aerifal dot cx @ 2014-03-02 0:13 UTC (permalink / raw)
To: glibc-bugs
https://sourceware.org/bugzilla/show_bug.cgi?id=16630
--- Comment #9 from Rich Felker <bugdal at aerifal dot cx> ---
I think it's likely that the patch submitted won't be needed (because the code
will hopefully just be removed instead), but either way, it's not a "WONTFIX"
and it would be inappropriate to mark it as such. It's just that we're waiting
to see whether applying this patch (or some variant of it) or just removing the
offending asm is the right solution.
--
You are receiving this mail because:
You are on the CC list for the bug.
^ permalink raw reply [flat|nested] 12+ messages in thread
* [Bug nptl/16630] Use SYSENTER for pthread_cond_broadcast/signal() (i.e. fix "FIXME: Ingo" issue)
2014-02-24 22:41 [Bug nptl/16630] New: Use SYSENTER for pthread_cond_broadcast/signal() (i.e. fix "FIXME: Ingo" issue) cjones.bugs at gmail dot com
` (8 preceding siblings ...)
2014-03-02 0:13 ` bugdal at aerifal dot cx
@ 2014-06-13 6:48 ` fweimer at redhat dot com
9 siblings, 0 replies; 12+ messages in thread
From: fweimer at redhat dot com @ 2014-06-13 6:48 UTC (permalink / raw)
To: glibc-bugs
https://sourceware.org/bugzilla/show_bug.cgi?id=16630
Florian Weimer <fweimer at redhat dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Flags| |security-
--
You are receiving this mail because:
You are on the CC list for the bug.
^ permalink raw reply [flat|nested] 12+ messages in thread