From: mulyadi.santosa@gmail.com (Mulyadi Santosa)
To: kernelnewbies@lists.kernelnewbies.org
Subject: syscalls performance
Date: Sat, 26 Feb 2011 11:31:08 +0700 [thread overview]
Message-ID: <AANLkTinrn43VRRrC0-FGdrWWuOsAdk_Zo5of7HbrgvON@mail.gmail.com> (raw)
In-Reply-To: <C8CB91A9-6C65-4556-95B4-9F881A3CE724@cs.ucsd.edu>
Hi Enrico...
On Sat, Feb 26, 2011 at 03:42, Enrico Granata <egranata@ucsd.edu> wrote:
>
>
> I modified the source code to show exactly how many clock ticks it is taking
> for each call. It seems that the behavior hinted by Mauro Romano Trajber is
> actually there:
> [enrico at espresso ~]$ ./syscallperf 15
> 4925
> 1190
> 942
watching strace, objdump etc etc, I roughly conclude the high initial
tsc number might be due to initial symbol resolve to mygetpid() and/or
syscall() (IIRC this is called PLT/GOT symbol resolve).
After the GOT/PLT table had the syscall/mygetpid address, the rest went fast.
PS: if using gcc -O2, seems like mygetpid() is really inlined....
--
regards,
Mulyadi Santosa
Freelance Linux trainer and consultant
blog: the-hydra.blogspot.com
training: mulyaditraining.blogspot.com
next prev parent reply other threads:[~2011-02-26 4:31 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-25 17:03 syscalls performance Mauro Romano Trajber
2011-02-25 17:15 ` Daniel Baluta
2011-02-25 18:22 ` Mauro Romano Trajber
2011-02-25 20:15 ` Daniel Baluta
2011-02-25 20:30 ` Mauro Romano Trajber
2011-02-25 20:42 ` Enrico Granata
2011-02-25 20:59 ` Jim Kukunas
2011-02-25 21:00 ` Enrico Granata
2011-02-25 22:03 ` Mauro Romano Trajber
2011-02-25 22:06 ` Daniel Baluta
2011-02-25 22:14 ` Enrico Granata
2011-02-26 4:31 ` Mulyadi Santosa [this message]
[not found] <D3CBA33B-3809-4AF5-9F66-0F2D256C4A82@cs.ucsd.edu>
2011-02-25 17:14 ` Enrico Granata
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