On 10/4/19 5:17 PM, Mikulas Patocka wrote: > If we are in a place where it is known that interrupts are enabled, > functions spin_lock_irq/spin_unlock_irq should be used instead of > spin_lock_irqsave/spin_unlock_irqrestore. > > spin_lock_irq and spin_unlock_irq are faster because the don't need to > push and pop the flags register. > > Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx> > I reviewed the patch and it looks good. As a minor addition, I attach a patch which updates the dm_clone_cond_set_range() comment. Moreover, I will send a complementary patch converting a few more uses of spin_lock_irqsave/spin_unlock_irqrestore to spin_lock_irq/spin_unlock_irq. Thanks, Nikos >From 097517d594cc127d2f21ca976f1e7df304e1ed10 Mon Sep 17 00:00:00 2001 From: Nikos Tsironis <ntsironis@xxxxxxxxxxx> Date: Mon, 7 Oct 2019 14:07:19 +0300 Subject: [PATCH] dm clone: Fix dm_clone_cond_set_range() comment Signed-off-by: Nikos Tsironis <ntsironis@xxxxxxxxxxx> --- drivers/md/dm-clone-metadata.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/md/dm-clone-metadata.h b/drivers/md/dm-clone-metadata.h index 434bff08508b..9d3d29e6a838 100644 --- a/drivers/md/dm-clone-metadata.h +++ b/drivers/md/dm-clone-metadata.h @@ -44,7 +44,9 @@ int dm_clone_set_region_hydrated(struct dm_clone_metadata *cmd, unsigned long re * @start: Starting region number * @nr_regions: Number of regions in the range * - * This function doesn't block, so it's safe to call it from interrupt context. + * This function doesn't block, but since it uses + * spin_lock_irq()/spin_unlock_irq() it's NOT safe to call it from any context + * where interrupts are disabled, e.g., from interrupt context. */ int dm_clone_cond_set_range(struct dm_clone_metadata *cmd, unsigned long start, unsigned long nr_regions); -- 2.11.0 -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
