From mboxrd@z Thu Jan 1 00:00:00 1970 From: zhaolei@cn.fujitsu.com (Zhaolei) Date: Tue, 13 Jan 2009 10:56:50 +0800 Subject: [ltt-dev] Degression from "fix-x86_64-sysenter-trace-race" In-Reply-To: <20090113021332.GA7852@Krystal> References: <496BEA99.7030901@cn.fujitsu.com> <20090113021332.GA7852@Krystal> Message-ID: <496C02F2.3020801@cn.fujitsu.com> Message-ID: <20090113025650.I3ByhLxerC86UHodzBdDB1X0T0j-KaaibbQyUC0b_Ko@z> * Mathieu Desnoyers Wrote: > * 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. Hello, Mathieu kernel config is send as attachment. I use RHEL's default config with ltt support. B.R. Zhaolei > > 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 >> > -------------- next part -------------- An embedded and charset-unspecified text was scrubbed... Name: config.ltt URL: