Reduce stack in vdev_cache_read

Moving the vdev_cache_entry_t struct ve_search from the stack to
the heap saves ~100 bytes.
This commit is contained in:
Brian Behlendorf 2010-08-02 13:56:27 -07:00
parent b3c82b1b18
commit 48669030fe
3 changed files with 13 additions and 3 deletions

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.topdeps Normal file
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master

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From: Brian Behlendorf <behlendorf1@llnl.gov>
Subject: [PATCH] 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>

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@ -244,7 +244,7 @@ int
vdev_cache_read(zio_t *zio) vdev_cache_read(zio_t *zio)
{ {
vdev_cache_t *vc = &zio->io_vd->vdev_cache; 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); uint64_t cache_offset = P2ALIGN(zio->io_offset, VCBS);
uint64_t cache_phase = P2PHASE(zio->io_offset, VCBS); uint64_t cache_phase = P2PHASE(zio->io_offset, VCBS);
zio_t *fio; zio_t *fio;
@ -267,8 +267,10 @@ vdev_cache_read(zio_t *zio)
mutex_enter(&vc->vc_lock); mutex_enter(&vc->vc_lock);
ve_search.ve_offset = cache_offset; ve_search = kmem_alloc(sizeof(vdev_cache_entry_t), KM_SLEEP);
ve = avl_find(&vc->vc_offset_tree, &ve_search, NULL); 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 != NULL) {
if (ve->ve_missed_update) { if (ve->ve_missed_update) {