On 3/12/07, Anton Blanchard <[EMAIL PROTECTED]> wrote:
Hi Nick, > Anyway, I'll keep experimenting. If anyone from MySQL wants to help look > at this, send me a mail (eg. especially with the sched_setscheduler issue, > you might be able to do something better). I took a look at this today and figured Id document it: http://ozlabs.org/~anton/linux/sysbench/ Bottom line: it looks like issues in the glibc malloc library, replacing it with the google malloc library fixes the negative scaling: # apt-get install libgoogle-perftools0 # LD_PRELOAD=/usr/lib/libtcmalloc.so /usr/sbin/mysqld
Quick datapoint, still collecting data and trying to verify it's always the case: on my 8-way Xeon, I'm actually seeing *much* worse performance with libtcmalloc.so compared to mainline. Am generating graphs and such still, but maybe someone else with x86_64 hardware could try the google PRELOAD and see if it helps/hurts (to rule out tester stupidity)? Thanks, Nish - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/