Re: [PATCH] sbitmap: don't update the allocation hint on clear after resize

From: Jens Axboe
Date: Sat Sep 17 2016 - 15:40:45 EST

On 09/17/2016 01:20 PM, Omar Sandoval wrote:
From: Omar Sandoval <osandov@xxxxxx>

If we have a bunch of high-numbered bits allocated and then we resize
the struct sbitmap_queue, when those bits get cleared, we'll update the
hint and then have to re-randomize it repeatedly. Avoid that by checking
that the cleared bit is still a valid hint. No measurable performance
difference in the common case.

Signed-off-by: Omar Sandoval <osandov@xxxxxx>

Small tweak to patch 6 that occurred to me after I sent the series out.
Feel free to fold it in to patch 6 or apply it separately as you see

No worries. I can't fold since the series was already applied, so I just
added the extra patch.

Jens Axboe