K 10
svn:author
V 5
markj
K 8
svn:date
V 27
2020-10-19T16:55:03.568280Z
K 7
svn:log
V 832
uma: Avoid depleting keg reserves when filling a bucket

zone_import() fetches a free or partially free slab from the keg and
then uses its items to populate an array, typically filling a bucket.
If a single allocation causes the keg to drop below its minimum reserve,
the inner loop ends.  However, if the bucket is still not full and
M_USE_RESERVE is specified, the outer loop will continue to fetch items
from the keg.

If M_USE_RESERVE is specified and the number of free items is below the
reserved limit, we should return only a single item.  Otherwise, if the
bucket size is larger than the reserve, all of the reserved items may
end up in a single per-CPU bucket, invisible to other CPUs.

Reviewed by:	rlibby
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D26771

END