Fix stack vdev_cache_read()

Moving the vdev_cache_entry_t struct ve_search from the stack to
the heap saves ~100 bytes.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>

diff --git a/module/zfs/vdev_cache.c b/module/zfs/vdev_cache.c
index a4b3442..c5439ba 100644 (file)
--- a/module/zfs/vdev_cache.c
+++ b/module/zfs/vdev_cache.c
@@ -244,7 +244,7 @@ int
 vdev_cache_read(zio_t *zio)
 {
        vdev_cache_t *vc = &zio->io_vd->vdev_cache;
-       vdev_cache_entry_t *ve, ve_search;
+       vdev_cache_entry_t *ve, *ve_search;
        uint64_t cache_offset = P2ALIGN(zio->io_offset, VCBS);
        ASSERTV(uint64_t cache_phase = P2PHASE(zio->io_offset, VCBS);)
        zio_t *fio;
@@ -267,8 +267,10 @@ vdev_cache_read(zio_t *zio)
 
        mutex_enter(&vc->vc_lock);
 
-       ve_search.ve_offset = cache_offset;
-       ve = avl_find(&vc->vc_offset_tree, &ve_search, NULL);
+       ve_search = kmem_alloc(sizeof(vdev_cache_entry_t), KM_SLEEP);
+       ve_search->ve_offset = cache_offset;
+       ve = avl_find(&vc->vc_offset_tree, ve_search, NULL);
+       kmem_free(ve_search, sizeof(vdev_cache_entry_t));
 
        if (ve != NULL) {
                if (ve->ve_missed_update) {