From 2fd77fff4b440c29b48c31db0ce2aec7d319959f Mon Sep 17 00:00:00 2001 From: Len Brown Date: Fri, 31 Jul 2015 12:46:17 -0400 Subject: PM / suspend: make sync() on suspend-to-RAM build-time optional The Linux kernel suspend path has traditionally invoked sys_sync() before freezing user threads. But sys_sync() can be expensive, and some user-space OS's do not want the kernel to pay the cost of sys_sync() on every suspend -- preferring invoke sync() from user-space if/when they want it. So make sys_sync on suspend build-time optional. The default is unchanged. Signed-off-by: Len Brown Signed-off-by: Rafael J. Wysocki --- kernel/power/suspend.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel/power/suspend.c') diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index 53266b729fd9..7e4cda4a8dd9 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -484,11 +484,13 @@ static int enter_state(suspend_state_t state) if (state == PM_SUSPEND_FREEZE) freeze_begin(); +#ifndef CONFIG_SUSPEND_SKIP_SYNC trace_suspend_resume(TPS("sync_filesystems"), 0, true); printk(KERN_INFO "PM: Syncing filesystems ... "); sys_sync(); printk("done.\n"); trace_suspend_resume(TPS("sync_filesystems"), 0, false); +#endif pr_debug("PM: Preparing system for sleep (%s)\n", pm_states[state]); error = suspend_prepare(state); -- cgit v1.2.3