Commit 2ee1abad authored by Dave Chinner's avatar Dave Chinner Committed by Alex Elder

xfs: improve metadata I/O merging in the elevator

Change all async metadata buffers to use [READ|WRITE]_META I/O types
so that the I/O doesn't get issued immediately. This allows merging of
adjacent metadata requests but still prioritises them over bulk data.
This shows a 10-15% improvement in sequential create speed of small
files.

Don't include the log buffers in this classification - leave them as
sync types so they are issued immediately.
Signed-off-by: default avatarDave Chinner <dgc@sgi.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarAlex Elder <aelder@sgi.com>
parent b44b1126
......@@ -1149,10 +1149,14 @@ _xfs_buf_ioapply(
if (bp->b_flags & XBF_ORDERED) {
ASSERT(!(bp->b_flags & XBF_READ));
rw = WRITE_BARRIER;
} else if (bp->b_flags & _XBF_RUN_QUEUES) {
} else if (bp->b_flags & XBF_LOG_BUFFER) {
ASSERT(!(bp->b_flags & XBF_READ_AHEAD));
bp->b_flags &= ~_XBF_RUN_QUEUES;
rw = (bp->b_flags & XBF_WRITE) ? WRITE_SYNC : READ_SYNC;
} else if (bp->b_flags & _XBF_RUN_QUEUES) {
ASSERT(!(bp->b_flags & XBF_READ_AHEAD));
bp->b_flags &= ~_XBF_RUN_QUEUES;
rw = (bp->b_flags & XBF_WRITE) ? WRITE_META : READ_META;
} else {
rw = (bp->b_flags & XBF_WRITE) ? WRITE :
(bp->b_flags & XBF_READ_AHEAD) ? READA : READ;
......
......@@ -55,6 +55,7 @@ typedef enum {
XBF_FS_MANAGED = (1 << 8), /* filesystem controls freeing memory */
XBF_ORDERED = (1 << 11), /* use ordered writes */
XBF_READ_AHEAD = (1 << 12), /* asynchronous read-ahead */
XBF_LOG_BUFFER = (1 << 13), /* this is a buffer used for the log */
/* flags used only as arguments to access routines */
XBF_LOCK = (1 << 14), /* lock requested */
......
......@@ -1441,6 +1441,7 @@ xlog_sync(xlog_t *log,
XFS_BUF_ZEROFLAGS(bp);
XFS_BUF_BUSY(bp);
XFS_BUF_ASYNC(bp);
bp->b_flags |= XBF_LOG_BUFFER;
/*
* Do an ordered write for the log block.
* Its unnecessary to flush the first split block in the log wrap case.
......@@ -1478,6 +1479,7 @@ xlog_sync(xlog_t *log,
XFS_BUF_ZEROFLAGS(bp);
XFS_BUF_BUSY(bp);
XFS_BUF_ASYNC(bp);
bp->b_flags |= XBF_LOG_BUFFER;
if (log->l_mp->m_flags & XFS_MOUNT_BARRIER)
XFS_BUF_ORDERED(bp);
dptr = XFS_BUF_PTR(bp);
......
......@@ -152,6 +152,7 @@ struct inodes_stat_t {
#define WRITE_SYNC_PLUG (WRITE | (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_NOIDLE))
#define WRITE_SYNC (WRITE_SYNC_PLUG | (1 << BIO_RW_UNPLUG))
#define WRITE_ODIRECT_PLUG (WRITE | (1 << BIO_RW_SYNCIO))
#define WRITE_META (WRITE | (1 << BIO_RW_META))
#define SWRITE_SYNC_PLUG \
(SWRITE | (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_NOIDLE))
#define SWRITE_SYNC (SWRITE_SYNC_PLUG | (1 << BIO_RW_UNPLUG))
......
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