From: compudj@krystal.dyndns.org (Mathieu Desnoyers)
Subject: [ltt-dev] Degression from "fix-x86_64-sysenter-trace-race"
Date: Mon, 12 Jan 2009 21:13:32 -0500 [thread overview]
Message-ID: <20090113021332.GA7852@Krystal> (raw)
In-Reply-To: <496BEA99.7030901@cn.fujitsu.com>
* Zhaolei (zhaolei at cn.fujitsu.com) wrote:
> Hello,
>
> I tested lttng's performance by tbench program in x86_64 platform.
> And I found patch named "fix-x86_64-sysenter-trace-race" makes large
> degression(about 5%).
> Here is test result:
>
> [----------PATCH----------] [TBENCH]
> lttng-kernel-trace-thread-flag-s390 1317.08
> lttng-kernel-trace-thread-flag-sh 1315.61
> lttng-kernel-trace-thread-flag-sparc 1305.02
> lttng-kernel-trace-thread-flag-sparc64 1314.06
> lttng-kernel-trace-thread-flag-um 1316.35
> fix-x86_64-sysenter-trace-race 1250.89
> lttng-kernel-trace-thread-flag-x86 1259.07
> lttng-kernel-trace-thread-flag-xtensa 1252.86
> lttng-kernel-trace-thread-flag-api 1253.35
> lttng-use-kernel-trace-thread-flag-api 1251.9
> stringify-support-commas 1247.11
>
> And if I remove this patch, degression is not happened:
> [----------PATCH----------] [TBENCH]
> lttng-kernel-trace-thread-flag-s390 1307.73
> lttng-kernel-trace-thread-flag-sh 1317.33
> lttng-kernel-trace-thread-flag-sparc 1306.85
> lttng-kernel-trace-thread-flag-sparc64 1303.62
> lttng-kernel-trace-thread-flag-um 1312.08
> lttng-kernel-trace-thread-flag-x86 1308.5
> lttng-kernel-trace-thread-flag-xtensa 1310.77
> lttng-kernel-trace-thread-flag-api 1309.05
> lttng-use-kernel-trace-thread-flag-api 1310.26
> stringify-support-commas 1307.69
>
> I want to know system's benchmark when lttng turn off,
> so test environment is following:
> - Compile kernel with lttng patch up to given one and default config,
> - Install kernel, Reboot system,
> (don't load any lttng module, don't run ltt-arm or lttctl)
> - Begin tbench test.
>
> Plarform is RHEL5.2 root filesystem with linux-2.6.27.7 and lttng-0.60 patchs.
> Hardware is 4 * Intel(R) Xeon(R) X5260 at 3.33GHz with 4G memory.
>
> I think [fix-x86_64-sysenter-trace-race] should not leads so large degression,
> But I tested several times and result is near.
>
Hrm, interesting. Can you give your full kernel .config ? I'd like to
see if the _TIF_SYSCALL_AUDIT or _TIF_SECCOMP bits are set.
If you have a better way to support asynchronously changing the thread
flags and still have the affected running threads running correctly, I'm
willing to consider it.
Mathieu
> B.R.
> Zhaolei
>
>
> _______________________________________________
> ltt-dev mailing list
> ltt-dev at lists.casi.polymtl.ca
> http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev
>
--
Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
next prev parent reply other threads:[~2009-01-13 2:13 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-01-13 1:12 Zhaolei
2009-01-13 2:13 ` Mathieu Desnoyers [this message]
2009-01-13 2:56 ` Zhaolei
2009-01-13 2:56 ` Zhaolei
2009-01-13 2:56 ` Zhaolei
2009-01-13 4:24 ` Mathieu Desnoyers
2009-01-13 7:59 ` Zhaolei
2009-01-13 13:47 ` Zhaolei
2009-01-15 1:41 ` Mathieu Desnoyers
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