Refactor uma_zfree_arg()

[jeff]

Summary

This is a more significant refactoring than uma_zalloc_arg() because it was in worse shape. We only need the zone lock if we're going to cache a bucket. The crossdomain logic really needed to be simplified and merged with the other case. Fundamentally we're just freeing a bucket and allocating a bucket, no matter which bucket that is.

[cem]

The bucket_push and item_dtor refactors look reasonable. I'm not super familiar with this area of code.

[markj]

sys/vm/uma_core.c

3214 ↗

(On Diff #64701)

Missing space after while.

3311 ↗

(On Diff #64701)

Isn't the use of lockfail redundant? We can write:

if (!ZONE_TRYLOCK(zone)) {
    ZONE_LOCK(zone);
    if (zone->uz_count < zone->uz_count_max)
        ....
}

[jeff]

Review feedback. Pull another function out, zone_free_bucket().

[markj]

sys/vm/uma_core.c

3317 ↗

(On Diff #64910)

Missing parens.