diff options
| author | alc <alc@FreeBSD.org> | 2005-02-13 21:51:50 +0000 |
|---|---|---|
| committer | alc <alc@FreeBSD.org> | 2005-02-13 21:51:50 +0000 |
| commit | 13e88b41bac03367de7406f96648f28a64fc7322 (patch) | |
| tree | 57ca8f35daa05acd6944cecccd9aaa5020281122 | |
| parent | 4f2d08a3315df4cdc5b9cf342c6c8f3c29b1b181 (diff) | |
| download | FreeBSD-src-13e88b41bac03367de7406f96648f28a64fc7322.zip FreeBSD-src-13e88b41bac03367de7406f96648f28a64fc7322.tar.gz | |
Request a CPU private mapping from sf_buf_alloc(). If the swap-backed
memory disk is larger than the number of available sf_bufs, this improves
performance on SMPs by eliminating interprocessor TLB shootdowns. For
example, with 6656 sf_bufs, the default on my test machine, and a 256MB
swap-backed memory disk, I see the command
"dd if=/dev/md0 of=/dev/null bs=64k" achieve ~489MB/sec with the default,
shared mappings, and ~587MB/sec with CPU private mappings.
| -rw-r--r-- | sys/dev/md/md.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/sys/dev/md/md.c b/sys/dev/md/md.c index 041c511..908d123 100644 --- a/sys/dev/md/md.c +++ b/sys/dev/md/md.c @@ -552,13 +552,15 @@ mdstart_swap(struct md_s *sc, struct bio *bp) m = vm_page_grab(sc->object, i, VM_ALLOC_NORMAL|VM_ALLOC_RETRY); VM_OBJECT_UNLOCK(sc->object); - sf = sf_buf_alloc(m, 0); + sched_pin(); + sf = sf_buf_alloc(m, SFB_CPUPRIVATE); VM_OBJECT_LOCK(sc->object); if (bp->bio_cmd == BIO_READ) { if (m->valid != VM_PAGE_BITS_ALL) rv = vm_pager_get_pages(sc->object, &m, 1, 0); if (rv == VM_PAGER_ERROR) { sf_buf_free(sf); + sched_unpin(); vm_page_lock_queues(); vm_page_wakeup(m); vm_page_unlock_queues(); @@ -570,6 +572,7 @@ mdstart_swap(struct md_s *sc, struct bio *bp) rv = vm_pager_get_pages(sc->object, &m, 1, 0); if (rv == VM_PAGER_ERROR) { sf_buf_free(sf); + sched_unpin(); vm_page_lock_queues(); vm_page_wakeup(m); vm_page_unlock_queues(); @@ -583,6 +586,7 @@ mdstart_swap(struct md_s *sc, struct bio *bp) rv = vm_pager_get_pages(sc->object, &m, 1, 0); if (rv == VM_PAGER_ERROR) { sf_buf_free(sf); + sched_unpin(); vm_page_lock_queues(); vm_page_wakeup(m); vm_page_unlock_queues(); @@ -594,6 +598,7 @@ mdstart_swap(struct md_s *sc, struct bio *bp) #endif } sf_buf_free(sf); + sched_unpin(); vm_page_lock_queues(); vm_page_wakeup(m); vm_page_activate(m); |
