public inbox for glibc-bugs@sourceware.org
help / color / mirror / Atom feed
* [Bug libc/14438] New: clock_gettime CLOCK_THREAD_CPUTIME_ID doesn't delegate to vsyscall
@ 2012-08-06 19:03 arun@sharma-home.net
2013-05-10 13:02 ` [Bug libc/14438] " siddhesh at redhat dot com
` (7 more replies)
0 siblings, 8 replies; 9+ messages in thread
From: arun@sharma-home.net @ 2012-08-06 19:03 UTC (permalink / raw)
To: glibc-bugs
http://sourceware.org/bugzilla/show_bug.cgi?id=14438
Bug #: 14438
Summary: clock_gettime CLOCK_THREAD_CPUTIME_ID doesn't delegate
to vsyscall
Product: glibc
Version: 2.17
Status: NEW
Severity: normal
Priority: P2
Component: libc
AssignedTo: unassigned@sourceware.org
ReportedBy: arun@sharma-home.net
CC: drepper.fsp@gmail.com
Classification: Unclassified
Created attachment 6566
--> http://sourceware.org/bugzilla/attachment.cgi?id=6566
clock_gettime() makes syscalls, but __vdso_clock_gettime doesn't.
clock_gettime(CLOCK_THREAD_CPUTIME_ID, &ts) seems to always make a syscall,
even on kernels that provide a vdso. Although upstream kernels don't have the
patches we're running with, I find this behavior surprising.
Why doesn't glibc always call __vdso_clock_gettime() and let the kernel decide
on the best implementation regardless of the clock id?
Relevant patches:
http://thread.gmane.org/gmane.linux.kernel/1231015/focus=1231016
--
Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug libc/14438] clock_gettime CLOCK_THREAD_CPUTIME_ID doesn't delegate to vsyscall
2012-08-06 19:03 [Bug libc/14438] New: clock_gettime CLOCK_THREAD_CPUTIME_ID doesn't delegate to vsyscall arun@sharma-home.net
@ 2013-05-10 13:02 ` siddhesh at redhat dot com
2013-05-10 14:09 ` arun@sharma-home.net
` (6 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: siddhesh at redhat dot com @ 2013-05-10 13:02 UTC (permalink / raw)
To: glibc-bugs
http://sourceware.org/bugzilla/show_bug.cgi?id=14438
Siddhesh Poyarekar <siddhesh at redhat dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |siddhesh at redhat dot com
--- Comment #1 from Siddhesh Poyarekar <siddhesh at redhat dot com> 2013-05-10 13:02:28 UTC ---
clock_gettime always calls __vdso_clock_gettime on x86_64. What are you
testing on?
--
Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug libc/14438] clock_gettime CLOCK_THREAD_CPUTIME_ID doesn't delegate to vsyscall
2012-08-06 19:03 [Bug libc/14438] New: clock_gettime CLOCK_THREAD_CPUTIME_ID doesn't delegate to vsyscall arun@sharma-home.net
2013-05-10 13:02 ` [Bug libc/14438] " siddhesh at redhat dot com
@ 2013-05-10 14:09 ` arun@sharma-home.net
2013-05-16 6:48 ` siddhesh at redhat dot com
` (5 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: arun@sharma-home.net @ 2013-05-10 14:09 UTC (permalink / raw)
To: glibc-bugs
http://sourceware.org/bugzilla/show_bug.cgi?id=14438
--- Comment #2 from Arun Sharma <arun@sharma-home.net> 2013-05-10 14:09:18 UTC ---
3.2 kernel plus out of tree patches which provide a vdso implementation for
this clock.
On May 10, 2013 6:02 AM, "siddhesh at redhat dot com" <
sourceware-bugzilla@sourceware.org> wrote:
> http://sourceware.org/bugzilla/show_bug.cgi?id=14438
>
> Siddhesh Poyarekar <siddhesh at redhat dot com> changed:
>
> What |Removed |Added
>
> ----------------------------------------------------------------------------
> CC| |siddhesh at redhat dot com
>
> --- Comment #1 from Siddhesh Poyarekar <siddhesh at redhat dot com>
> 2013-05-10 13:02:28 UTC ---
> clock_gettime always calls __vdso_clock_gettime on x86_64. What are you
> testing on?
>
> --
> Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=email
> ------- You are receiving this mail because: -------
> You reported the bug.
>
--
Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug libc/14438] clock_gettime CLOCK_THREAD_CPUTIME_ID doesn't delegate to vsyscall
2012-08-06 19:03 [Bug libc/14438] New: clock_gettime CLOCK_THREAD_CPUTIME_ID doesn't delegate to vsyscall arun@sharma-home.net
2013-05-10 13:02 ` [Bug libc/14438] " siddhesh at redhat dot com
2013-05-10 14:09 ` arun@sharma-home.net
@ 2013-05-16 6:48 ` siddhesh at redhat dot com
2013-07-26 18:24 ` neleai at seznam dot cz
` (4 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: siddhesh at redhat dot com @ 2013-05-16 6:48 UTC (permalink / raw)
To: glibc-bugs
http://sourceware.org/bugzilla/show_bug.cgi?id=14438
--- Comment #3 from Siddhesh Poyarekar <siddhesh at redhat dot com> 2013-05-16 06:48:47 UTC ---
(In reply to comment #2)
> 3.2 kernel plus out of tree patches which provide a vdso implementation for
> this clock.
x86_64 or something else? x86_64 calls __vdso_clock_gettime.
--
Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug libc/14438] clock_gettime CLOCK_THREAD_CPUTIME_ID doesn't delegate to vsyscall
2012-08-06 19:03 [Bug libc/14438] New: clock_gettime CLOCK_THREAD_CPUTIME_ID doesn't delegate to vsyscall arun@sharma-home.net
` (2 preceding siblings ...)
2013-05-16 6:48 ` siddhesh at redhat dot com
@ 2013-07-26 18:24 ` neleai at seznam dot cz
2013-07-26 18:37 ` arun@sharma-home.net
` (3 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: neleai at seznam dot cz @ 2013-07-26 18:24 UTC (permalink / raw)
To: glibc-bugs
http://sourceware.org/bugzilla/show_bug.cgi?id=14438
Ondrej Bilka <neleai at seznam dot cz> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |WAITING
CC| |neleai at seznam dot cz
--
You are receiving this mail because:
You are on the CC list for the bug.
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug libc/14438] clock_gettime CLOCK_THREAD_CPUTIME_ID doesn't delegate to vsyscall
2012-08-06 19:03 [Bug libc/14438] New: clock_gettime CLOCK_THREAD_CPUTIME_ID doesn't delegate to vsyscall arun@sharma-home.net
` (3 preceding siblings ...)
2013-07-26 18:24 ` neleai at seznam dot cz
@ 2013-07-26 18:37 ` arun@sharma-home.net
2013-07-27 2:45 ` siddhesh at redhat dot com
` (2 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: arun@sharma-home.net @ 2013-07-26 18:37 UTC (permalink / raw)
To: glibc-bugs
http://sourceware.org/bugzilla/show_bug.cgi?id=14438
--- Comment #4 from Arun Sharma <arun@sharma-home.net> ---
x86_64. IIRC: the implementation calls vdso for some clockids, but not others.
--
You are receiving this mail because:
You are on the CC list for the bug.
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug libc/14438] clock_gettime CLOCK_THREAD_CPUTIME_ID doesn't delegate to vsyscall
2012-08-06 19:03 [Bug libc/14438] New: clock_gettime CLOCK_THREAD_CPUTIME_ID doesn't delegate to vsyscall arun@sharma-home.net
` (4 preceding siblings ...)
2013-07-26 18:37 ` arun@sharma-home.net
@ 2013-07-27 2:45 ` siddhesh at redhat dot com
2013-10-04 15:53 ` arun@sharma-home.net
2014-06-17 18:47 ` fweimer at redhat dot com
7 siblings, 0 replies; 9+ messages in thread
From: siddhesh at redhat dot com @ 2013-07-27 2:45 UTC (permalink / raw)
To: glibc-bugs
http://sourceware.org/bugzilla/show_bug.cgi?id=14438
--- Comment #5 from Siddhesh Poyarekar <siddhesh at redhat dot com> ---
It calls vdso_clock_gettime for all clockids. If vdso function has support for
some clockids but not others, for which it does a context switch into the
kernel.
sysdeps/unix/clock_gettime.c:
...
default:
#ifdef SYSDEP_GETTIME_CPU
SYSDEP_GETTIME_CPU (clock_id, tp);
#endif
...
sysdeps/unix/sysv/linux/clock_gettime.c
...
#define SYSDEP_GETTIME_CPU(clock_id, tp) \
retval = SYSCALL_GETTIME (clock_id, tp); \
break
...
sysdeps/unix/sysv/linux/x86_64/clock_gettime.c
...
# define SYSCALL_GETTIME(id, tp) \
({ long int (*f) (clockid_t, struct timespec *) = __vdso_clock_gettime; \
long int v_ret; \
PTR_DEMANGLE (f); \
v_ret = f (id, tp); \
if (INTERNAL_SYSCALL_ERROR_P (v_ret, )) { \
__set_errno (INTERNAL_SYSCALL_ERRNO (v_ret, )); \
v_ret = -1; \
} \
v_ret; })
...
--
You are receiving this mail because:
You are on the CC list for the bug.
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug libc/14438] clock_gettime CLOCK_THREAD_CPUTIME_ID doesn't delegate to vsyscall
2012-08-06 19:03 [Bug libc/14438] New: clock_gettime CLOCK_THREAD_CPUTIME_ID doesn't delegate to vsyscall arun@sharma-home.net
` (5 preceding siblings ...)
2013-07-27 2:45 ` siddhesh at redhat dot com
@ 2013-10-04 15:53 ` arun@sharma-home.net
2014-06-17 18:47 ` fweimer at redhat dot com
7 siblings, 0 replies; 9+ messages in thread
From: arun@sharma-home.net @ 2013-10-04 15:53 UTC (permalink / raw)
To: glibc-bugs
http://sourceware.org/bugzilla/show_bug.cgi?id=14438
Arun Sharma <arun@sharma-home.net> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|WAITING |RESOLVED
Resolution|--- |FIXED
--- Comment #6 from Arun Sharma <arun@sharma-home.net> ---
Verified in glibc-2.14. Thanks for looking into this!
--
You are receiving this mail because:
You are on the CC list for the bug.
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug libc/14438] clock_gettime CLOCK_THREAD_CPUTIME_ID doesn't delegate to vsyscall
2012-08-06 19:03 [Bug libc/14438] New: clock_gettime CLOCK_THREAD_CPUTIME_ID doesn't delegate to vsyscall arun@sharma-home.net
` (6 preceding siblings ...)
2013-10-04 15:53 ` arun@sharma-home.net
@ 2014-06-17 18:47 ` fweimer at redhat dot com
7 siblings, 0 replies; 9+ messages in thread
From: fweimer at redhat dot com @ 2014-06-17 18:47 UTC (permalink / raw)
To: glibc-bugs
https://sourceware.org/bugzilla/show_bug.cgi?id=14438
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] 9+ messages in thread
end of thread, other threads:[~2014-06-17 18:47 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2012-08-06 19:03 [Bug libc/14438] New: clock_gettime CLOCK_THREAD_CPUTIME_ID doesn't delegate to vsyscall arun@sharma-home.net
2013-05-10 13:02 ` [Bug libc/14438] " siddhesh at redhat dot com
2013-05-10 14:09 ` arun@sharma-home.net
2013-05-16 6:48 ` siddhesh at redhat dot com
2013-07-26 18:24 ` neleai at seznam dot cz
2013-07-26 18:37 ` arun@sharma-home.net
2013-07-27 2:45 ` siddhesh at redhat dot com
2013-10-04 15:53 ` arun@sharma-home.net
2014-06-17 18:47 ` fweimer at redhat dot com
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).