On Mon, Jan 06, 2020 at 12:14:50PM -0500, Dennis Zhou wrote: > On Mon, Jan 06, 2020 at 04:25:42PM +0100, David Sterba wrote: > > On Thu, Jan 02, 2020 at 04:26:34PM -0500, Dennis Zhou wrote: > > > Dave applied 1-12 from v6 [1]. This is a follow up cleaning up the > > > remaining 10 patches adding 2 more to deal with a rare -1 [2] that I > > > haven't quite figured out how to repro. This is also available at [3]. > > > > > > This series is on top of btrfs-devel#misc-next-with-discard-v6 0c7be920bd7d. > > > > > > [1] https://lore.kernel.org/linux-btrfs/cover.1576195673.git.dennis@xxxxxxxxxx/ > > > [2] https://lore.kernel.org/linux-btrfs/20191217145541.GE3929@xxxxxxx/ > > > [3] https://git.kernel.org/pub/scm/linux/kernel/git/dennis/misc.git/log/?h=async-discard > > > > > > Dennis Zhou (12): > > > btrfs: calculate discard delay based on number of extents > > > btrfs: add bps discard rate limit for async discard > > > btrfs: limit max discard size for async discard > > > btrfs: make max async discard size tunable > > > btrfs: have multiple discard lists > > > btrfs: only keep track of data extents for async discard > > > btrfs: keep track of discard reuse stats > > > btrfs: add async discard header > > > btrfs: increase the metadata allowance for the free_space_cache > > > btrfs: make smaller extents more likely to go into bitmaps > > > btrfs: ensure removal of discardable_* in free_bitmap() > > > btrfs: add correction to handle -1 edge case in async discard > > > > I found this lockdep warning on the machine but can't tell what was the > > exact load at the time. I did a few copy/delete/balance and git checkout > > rounds, similar to the first testing loads. The branch tested was > > basically current misc-next: > > I've definitely ran into an mmap_sem circular lockdep warning before, > but I believe at the time I was able to repro it without my patches on > top. > > Besides that, I'm not sure how my series would be the trigger for this. > I'll take a closer look today. Thanks, I don't remember the exact lockdep report, though I've seen some transient mmap_sem warnings but nothing recent. What's weird is the sr_mutex, that's from scsi cdrom. There is one on the machine so I guess this is machine-specific and not related to the patchset.
