From: Aaro Koskinen Date: Wed, 4 Mar 2009 18:07:41 +0000 (-0800) Subject: ARM: OMAP: sched_clock() corrected X-Git-Tag: v2.6.29~38^2~4^2~2 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=80ea3bac3a47bc73efa334d0dd57099d0ff14216;p=pandora-kernel.git ARM: OMAP: sched_clock() corrected After my OMAP3 board has been running for a while, I'm seeing weird latency traces like this: sh-1574 0d.h2 153us : do_timer (tick_do_update_jiffies64) sh-1574 0d.h2 153us : update_wall_time (do_timer) sh-1574 0d.h2 153us!: omap_32k_read (update_wall_time) sh-1574 0d.h2 1883us : update_xtime_cache (update_wall_time) sh-1574 0d.h2 1883us : clocksource_get_next (update_wall_time) sh-1574 0d.h2 1883us+: _spin_lock_irqsave (clocksource_get_next) and after a while: sh-17818 0d.h3 153us : do_timer (tick_do_update_jiffies64) sh-17818 0d.h3 153us : update_wall_time (do_timer) sh-17818 0d.h3 153us!: omap_32k_read (update_wall_time) sh-17818 0d.h3 1915us : update_xtime_cache (update_wall_time) sh-17818 0d.h3 1915us+: clocksource_get_next (update_wall_time) sh-17818 0d.h3 1945us : _spin_lock_irqsave (clocksource_get_next) Turns out that sched_clock() is using cyc2ns(), which returns NTP adjusted time. The sched_clock() frequency should not be adjusted. The patch deletes omap_32k_ticks_to_nsecs() and rewrites sched_clock() to do the conversion using the constant multiplier. Signed-off-by: Aaro Koskinen Signed-off-by: Tony Lindgren --- Reading git-diff-tree failed