On Wed, 14 Jan 2009 21:51:22 +0100 Ingo Molnar <mingo@xxxxxxx> wrote: > > * Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > > > > > Do people enable CONFIG_SCHED_DEBUG? > > > > > > If they suspect performance problems and want to analyze them? > > > > The vast majority of users do not and usually cannot compile their own > > kernels. > > ... which they derive from distro kernels or some old .config they always > used, via 'make oldconfig'. You are arguing against well-established facts > here. > > If you dont believe my word for it, here's an analysis of all kernel > configs posted to lkml in the past 8 months: > > $ grep ^CONFIG_SCHED_DEBUG linux-kernel | wc -l > 424 > > $ grep 'CONFIG_SCHED_DEBUG is not' linux-kernel | wc -l > 109 > > i.e. CONFIG_SCHED_DEBUG=y is set in 80% of the configs. A large majority > of testers has it enabled and /sys/debug/sched_features was always a good > mechanism that we used for runtime toggles. You just disproved your own case :( > > > Note that CONFIG_SCHED_DEBUG=y is also the default. > > > > akpm:/usr/src/25> echo $ARCH > > x86_64 > > akpm:/usr/src/25> make defconfig > > *** Default configuration is based on 'x86_64_defconfig' > > x86 defconfig is used too, but it's a pretty rare usage. > > Under default i mean the customary meaning of default config: it's the > default if you come via 'make oldconfig' or if you derive your config from > a distro config: > > | config SCHED_DEBUG > | bool "Collect scheduler debugging info" > | depends on DEBUG_KERNEL && PROC_FS > | default y > This simply isn't reliable. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
