On Wed, 2011-06-15 at 13:57 -0700, Andi Kleen wrote: > > 7.44% exim [kernel.kallsyms] [k] format_decode > > | > > --- format_decod > > > This is a glibc issue. exim calls libdb and libdb asks sysconf for the > number of CPUs to tune > its locking, and glibc reads /proc/stat. And /proc/stat is incredible slow. > > I would blame glibc, but in this case it's really the kernel to blame > for not providing proper > interface. > > This was my motivation for the sysconf() syscall I submitted some time ago. > https://lkml.org/lkml/2011/5/13/455 > > Anyways a quick workaround is to use this LD_PRELOAD: > http://halobates.de/smallsrc/sysconf.c > But it's not 100% equivalent. > Thanks to Andi for providing the info. We've used this workaround in our testing so it will not mask true kernel scaling bottlenecks. Tim -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>