From: Anton Blanchard Date: Sun, 16 May 2010 20:02:39 +0000 (+0000) Subject: powerpc: Use smt_snooze_delay=-1 to always busy loop X-Git-Tag: v2.6.35-rc1~450^2~5 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b878dc00595440586874952dd85ce9b803360b87;p=pandora-kernel.git powerpc: Use smt_snooze_delay=-1 to always busy loop Right now if we want to busy loop and not give up any time to the hypervisor we put a very large value into smt_snooze_delay. This is sometimes useful when running a single partition and you want to avoid any latencies due to the hypervisor or CPU power state transitions. While this works, it's a bit ugly - how big a number is enough now we have NO_HZ and can be idle for a very long time. The patch below makes smt_snooze_delay signed, and a negative value means loop forever: echo -1 > /sys/devices/system/cpu/cpu0/smt_snooze_delay This change shouldn't affect the existing userspace tools (eg ppc64_cpu), but I'm cc-ing Nathan just to be sure. Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt --- Reading git-diff-tree failed