Merge tag 'for-6.3-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave...

Pull btrfs fixes from David Sterba:
 "Two patches fixing the problem with aync discard.

  The default settings had a low IOPS limit and processing a large batch
  to discard would take a long time. On laptops this can cause increased
  power consumption due to disk activity.

  As async discard has been on by default since 6.2 this likely affects
  a lot of users.

  Summary:

   - increase the default IOPS limit 10x which reportedly helped

   - setting the sysfs IOPS value to 0 now does not throttle anymore
     allowing the discards to be processed at full speed. Previously
     there was an arbitrary 6 hour target for processing the pending
     batch"

* tag 'for-6.3-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: reinterpret async discard iops_limit=0 as no delay
  btrfs: set default discard iops_limit to 1000

diff --git a/fs/btrfs/discard.c b/fs/btrfs/discard.c
index 317aeff..a6d77fe 100644 (file)
--- a/fs/btrfs/discard.c
+++ b/fs/btrfs/discard.c
@@ -56,11 +56,9 @@
 #define BTRFS_DISCARD_DELAY            (120ULL * NSEC_PER_SEC)
 #define BTRFS_DISCARD_UNUSED_DELAY     (10ULL * NSEC_PER_SEC)
 
-/* Target completion latency of discarding all discardable extents */
-#define BTRFS_DISCARD_TARGET_MSEC      (6 * 60 * 60UL * MSEC_PER_SEC)
 #define BTRFS_DISCARD_MIN_DELAY_MSEC   (1UL)
 #define BTRFS_DISCARD_MAX_DELAY_MSEC   (1000UL)
-#define BTRFS_DISCARD_MAX_IOPS         (10U)
+#define BTRFS_DISCARD_MAX_IOPS         (1000U)
 
 /* Monotonically decreasing minimum length filters after index 0 */
 static int discard_minlen[BTRFS_NR_DISCARD_LISTS] = {
@@ -577,6 +575,7 @@ void btrfs_discard_calc_delay(struct btrfs_discard_ctl *discard_ctl)
        s32 discardable_extents;
        s64 discardable_bytes;
        u32 iops_limit;
+       unsigned long min_delay = BTRFS_DISCARD_MIN_DELAY_MSEC;
        unsigned long delay;
 
        discardable_extents = atomic_read(&discard_ctl->discardable_extents);
@@ -607,13 +606,19 @@ void btrfs_discard_calc_delay(struct btrfs_discard_ctl *discard_ctl)
        }
 
        iops_limit = READ_ONCE(discard_ctl->iops_limit);
-       if (iops_limit)
+
+       if (iops_limit) {
                delay = MSEC_PER_SEC / iops_limit;
-       else
-               delay = BTRFS_DISCARD_TARGET_MSEC / discardable_extents;
+       } else {
+               /*
+                * Unset iops_limit means go as fast as possible, so allow a
+                * delay of 0.
+                */
+               delay = 0;
+               min_delay = 0;
+       }
 
-       delay = clamp(delay, BTRFS_DISCARD_MIN_DELAY_MSEC,
-                     BTRFS_DISCARD_MAX_DELAY_MSEC);
+       delay = clamp(delay, min_delay, BTRFS_DISCARD_MAX_DELAY_MSEC);
        discard_ctl->delay_ms = delay;
 
        spin_unlock(&discard_ctl->lock);