Module Name: src
Committed By: jdolecek
Date: Sat Dec 2 17:29:55 UTC 2017
Modified Files:
src/sys/kern: vfs_wapbl.c
Log Message:
according to benchmark extracting pkgsrc.tar, using FUA and hence waiting
for each transfer to write through to the medium is way slower than just
letting the drive use a cached write and doing DIOCCACHESYNC on the end
Results were (fs block 32KB / frag 4KB, partition aligned on 32KB boundary):
HDD at siisata(4): no-FUA: 108 sec w/FUA: 294 sec
SSD at ahcisata(4): no-FUA: 73 sec w/FUA: 502 sec
change the flag so that FUA is only used for the commit block write;
for journal data write, only pass DPO, rely on the cache flush to get them
to media
To generate a diff of this commit:
cvs rdiff -u -r1.100 -r1.101 src/sys/kern/vfs_wapbl.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/vfs_wapbl.c
diff -u src/sys/kern/vfs_wapbl.c:1.100 src/sys/kern/vfs_wapbl.c:1.101
--- src/sys/kern/vfs_wapbl.c:1.100 Fri Oct 27 12:25:15 2017
+++ src/sys/kern/vfs_wapbl.c Sat Dec 2 17:29:55 2017
@@ -1,4 +1,4 @@
-/* $NetBSD: vfs_wapbl.c,v 1.100 2017/10/27 12:25:15 joerg Exp $ */
+/* $NetBSD: vfs_wapbl.c,v 1.101 2017/12/02 17:29:55 jdolecek Exp $ */
/*-
* Copyright (c) 2003, 2008, 2009 The NetBSD Foundation, Inc.
@@ -36,7 +36,7 @@
#define WAPBL_INTERNAL
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_wapbl.c,v 1.100 2017/10/27 12:25:15 joerg Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_wapbl.c,v 1.101 2017/12/02 17:29:55 jdolecek Exp $");
#include <sys/param.h>
#include <sys/bitops.h>
@@ -239,10 +239,9 @@ struct wapbl {
(wapbl_allow_dpofua && ISSET((wl)->wl_dkcache, DKCACHE_FUA))
#define WAPBL_JFLAGS(wl) \
(WAPBL_USE_FUA(wl) ? (wl)->wl_jwrite_flags : 0)
-#define WAPBL_MFLAGS(wl) \
- (WAPBL_USE_FUA(wl) ? (wl)->wl_mwrite_flags : 0)
+#define WAPBL_JDATA_FLAGS(wl) \
+ (WAPBL_JFLAGS(wl) & B_MEDIA_DPO) /* only DPO */
int wl_jwrite_flags; /* r: journal write flags */
- int wl_mwrite_flags; /* r: metadata write flags */
};
#ifdef WAPBL_DEBUG_PRINT
@@ -444,10 +443,8 @@ wapbl_dkcache_init(struct wapbl *wl)
}
/* Use FUA instead of cache flush if available */
- if (ISSET(wl->wl_dkcache, DKCACHE_FUA)) {
+ if (ISSET(wl->wl_dkcache, DKCACHE_FUA))
wl->wl_jwrite_flags |= B_MEDIA_FUA;
- wl->wl_mwrite_flags |= B_MEDIA_FUA;
- }
/* Use DPO for journal writes if available */
if (ISSET(wl->wl_dkcache, DKCACHE_DPO))
@@ -998,7 +995,7 @@ wapbl_buffered_write_async(struct wapbl
KASSERT(TAILQ_FIRST(&wl->wl_iobufs) == bp);
TAILQ_REMOVE(&wl->wl_iobufs, bp, b_wapbllist);
- bp->b_flags = B_WRITE | WAPBL_JFLAGS(wl);
+ bp->b_flags |= B_WRITE;
bp->b_cflags = BC_BUSY; /* mandatory, asserted by biowait() */
bp->b_oflags = 0;
bp->b_bcount = bp->b_resid;
@@ -1043,7 +1040,7 @@ again:
error = biowait(bp);
/* reset for reuse */
- bp->b_blkno = bp->b_resid = 0;
+ bp->b_blkno = bp->b_resid = bp->b_flags = 0;
TAILQ_INSERT_TAIL(&wl->wl_iobufs, bp, b_wapbllist);
found = true;
@@ -1067,7 +1064,8 @@ again:
* wapbl_buffered_flush.
*/
static int
-wapbl_buffered_write(void *data, size_t len, struct wapbl *wl, daddr_t pbn)
+wapbl_buffered_write(void *data, size_t len, struct wapbl *wl, daddr_t pbn,
+ int bflags)
{
size_t resid;
struct buf *bp;
@@ -1096,8 +1094,10 @@ again:
* If this write goes to an empty buffer we have to
* save the disk block address first.
*/
- if (bp->b_blkno == 0)
+ if (bp->b_blkno == 0) {
bp->b_blkno = pbn;
+ bp->b_flags |= bflags;
+ }
/*
* Remaining space so this buffer ends on a buffer size boundary.
@@ -1164,7 +1164,8 @@ wapbl_circ_write(struct wapbl *wl, void
#ifdef _KERNEL
pbn = btodb(pbn << wl->wl_log_dev_bshift);
#endif
- error = wapbl_buffered_write(data, slen, wl, pbn);
+ error = wapbl_buffered_write(data, slen, wl, pbn,
+ WAPBL_JDATA_FLAGS(wl));
if (error)
return error;
data = (uint8_t *)data + slen;
@@ -1175,7 +1176,8 @@ wapbl_circ_write(struct wapbl *wl, void
#ifdef _KERNEL
pbn = btodb(pbn << wl->wl_log_dev_bshift);
#endif
- error = wapbl_buffered_write(data, len, wl, pbn);
+ error = wapbl_buffered_write(data, len, wl, pbn,
+ WAPBL_JDATA_FLAGS(wl));
if (error)
return error;
off += len;
@@ -1925,9 +1927,6 @@ wapbl_flush(struct wapbl *wl, int waitfo
bp->b_iodone = wapbl_biodone;
bp->b_private = we;
- /* make sure the block is saved sync when FUA in use */
- bp->b_flags |= WAPBL_MFLAGS(wl);
-
bremfree(bp);
wapbl_remove_buf_locked(wl, bp);
mutex_exit(&wl->wl_mtx);
@@ -2399,8 +2398,8 @@ wapbl_cache_sync(struct wapbl *wl, const
int force = 1;
int error;
- /* Skip full cache sync if disabled, or when using FUA */
- if (!wapbl_flush_disk_cache || WAPBL_USE_FUA(wl)) {
+ /* Skip full cache sync if disabled */
+ if (!wapbl_flush_disk_cache) {
return 0;
}
if (verbose) {
@@ -2459,8 +2458,10 @@ wapbl_write_commit(struct wapbl *wl, off
if (error)
return error;
/*
- * flush disk cache to ensure that blocks we've written are actually
+ * Flush disk cache to ensure that blocks we've written are actually
* written to the stable storage before the commit header.
+ * This flushes to disk not only journal blocks, but also all
+ * metadata blocks, written asynchronously since previous commit.
*
* XXX Calc checksum here, instead we do this for now
*/
@@ -2489,7 +2490,7 @@ wapbl_write_commit(struct wapbl *wl, off
#ifdef _KERNEL
pbn = btodb(pbn << wc->wc_log_dev_bshift);
#endif
- error = wapbl_buffered_write(wc, wc->wc_len, wl, pbn);
+ error = wapbl_buffered_write(wc, wc->wc_len, wl, pbn, WAPBL_JFLAGS(wl));
if (error)
return error;
error = wapbl_buffered_flush(wl, true);
@@ -2497,10 +2498,12 @@ wapbl_write_commit(struct wapbl *wl, off
return error;
/*
- * flush disk cache to ensure that the commit header is actually
- * written before meta data blocks.
+ * Flush disk cache to ensure that the commit header is actually
+ * written before meta data blocks. Commit block is written using
+ * FUA when enabled, in that case this flush is not needed.
*/
- wapbl_cache_sync(wl, "2");
+ if (!WAPBL_USE_FUA(wl))
+ wapbl_cache_sync(wl, "2");
/*
* If the generation number was zero, write it out a second time.
