[XFS] Improve buffered read throughput by removing unnecessary timer calls
that showed in ´kernel profiles.
SGI-PV: 925163
SGI-Modid: xfs-linux:xfs-kern:23861a
Signed-off-by: Nathan Scott <nathans@sgi.com>
diff --git a/fs/xfs/linux-2.6/xfs_iops.c b/fs/xfs/linux-2.6/xfs_iops.c
index 77708a8..68c83ec 100644
--- a/fs/xfs/linux-2.6/xfs_iops.c
+++ b/fs/xfs/linux-2.6/xfs_iops.c
@@ -69,6 +69,137 @@
#include <linux/xattr.h>
#include <linux/namei.h>
+/*
+ * Change the requested timestamp in the given inode.
+ * We don't lock across timestamp updates, and we don't log them but
+ * we do record the fact that there is dirty information in core.
+ *
+ * NOTE -- callers MUST combine XFS_ICHGTIME_MOD or XFS_ICHGTIME_CHG
+ * with XFS_ICHGTIME_ACC to be sure that access time
+ * update will take. Calling first with XFS_ICHGTIME_ACC
+ * and then XFS_ICHGTIME_MOD may fail to modify the access
+ * timestamp if the filesystem is mounted noacctm.
+ */
+void
+xfs_ichgtime(
+ xfs_inode_t *ip,
+ int flags)
+{
+ struct inode *inode = LINVFS_GET_IP(XFS_ITOV(ip));
+ timespec_t tv;
+
+ /*
+ * We're not supposed to change timestamps in readonly-mounted
+ * filesystems. Throw it away if anyone asks us.
+ */
+ if (unlikely(IS_RDONLY(inode)))
+ return;
+
+ /*
+ * Don't update access timestamps on reads if mounted "noatime".
+ * Throw it away if anyone asks us.
+ */
+ if (unlikely(
+ (ip->i_mount->m_flags & XFS_MOUNT_NOATIME || IS_NOATIME(inode)) &&
+ (flags & (XFS_ICHGTIME_ACC|XFS_ICHGTIME_MOD|XFS_ICHGTIME_CHG)) ==
+ XFS_ICHGTIME_ACC))
+ return;
+
+ nanotime(&tv);
+ if (flags & XFS_ICHGTIME_MOD) {
+ inode->i_mtime = tv;
+ ip->i_d.di_mtime.t_sec = (__int32_t)tv.tv_sec;
+ ip->i_d.di_mtime.t_nsec = (__int32_t)tv.tv_nsec;
+ }
+ if (flags & XFS_ICHGTIME_ACC) {
+ inode->i_atime = tv;
+ ip->i_d.di_atime.t_sec = (__int32_t)tv.tv_sec;
+ ip->i_d.di_atime.t_nsec = (__int32_t)tv.tv_nsec;
+ }
+ if (flags & XFS_ICHGTIME_CHG) {
+ inode->i_ctime = tv;
+ ip->i_d.di_ctime.t_sec = (__int32_t)tv.tv_sec;
+ ip->i_d.di_ctime.t_nsec = (__int32_t)tv.tv_nsec;
+ }
+
+ /*
+ * We update the i_update_core field _after_ changing
+ * the timestamps in order to coordinate properly with
+ * xfs_iflush() so that we don't lose timestamp updates.
+ * This keeps us from having to hold the inode lock
+ * while doing this. We use the SYNCHRONIZE macro to
+ * ensure that the compiler does not reorder the update
+ * of i_update_core above the timestamp updates above.
+ */
+ SYNCHRONIZE();
+ ip->i_update_core = 1;
+ if (!(inode->i_state & I_LOCK))
+ mark_inode_dirty_sync(inode);
+}
+
+/*
+ * Variant on the above which avoids querying the system clock
+ * in situations where we know the Linux inode timestamps have
+ * just been updated (and so we can update our inode cheaply).
+ * We also skip the readonly and noatime checks here, they are
+ * also catered for already.
+ */
+void
+xfs_ichgtime_fast(
+ xfs_inode_t *ip,
+ struct inode *inode,
+ int flags)
+{
+ timespec_t *tvp;
+
+ /*
+ * We're not supposed to change timestamps in readonly-mounted
+ * filesystems. Throw it away if anyone asks us.
+ */
+ if (unlikely(IS_RDONLY(inode)))
+ return;
+
+ /*
+ * Don't update access timestamps on reads if mounted "noatime".
+ * Throw it away if anyone asks us.
+ */
+ if (unlikely(
+ (ip->i_mount->m_flags & XFS_MOUNT_NOATIME || IS_NOATIME(inode)) &&
+ ((flags & (XFS_ICHGTIME_ACC|XFS_ICHGTIME_MOD|XFS_ICHGTIME_CHG)) ==
+ XFS_ICHGTIME_ACC)))
+ return;
+
+ if (flags & XFS_ICHGTIME_MOD) {
+ tvp = &inode->i_mtime;
+ ip->i_d.di_mtime.t_sec = (__int32_t)tvp->tv_sec;
+ ip->i_d.di_mtime.t_nsec = (__int32_t)tvp->tv_nsec;
+ }
+ if (flags & XFS_ICHGTIME_ACC) {
+ tvp = &inode->i_atime;
+ ip->i_d.di_atime.t_sec = (__int32_t)tvp->tv_sec;
+ ip->i_d.di_atime.t_nsec = (__int32_t)tvp->tv_nsec;
+ }
+ if (flags & XFS_ICHGTIME_CHG) {
+ tvp = &inode->i_ctime;
+ ip->i_d.di_ctime.t_sec = (__int32_t)tvp->tv_sec;
+ ip->i_d.di_ctime.t_nsec = (__int32_t)tvp->tv_nsec;
+ }
+
+ /*
+ * We update the i_update_core field _after_ changing
+ * the timestamps in order to coordinate properly with
+ * xfs_iflush() so that we don't lose timestamp updates.
+ * This keeps us from having to hold the inode lock
+ * while doing this. We use the SYNCHRONIZE macro to
+ * ensure that the compiler does not reorder the update
+ * of i_update_core above the timestamp updates above.
+ */
+ SYNCHRONIZE();
+ ip->i_update_core = 1;
+ if (!(inode->i_state & I_LOCK))
+ mark_inode_dirty_sync(inode);
+}
+
/*
* Pull the link count and size up from the xfs inode to the linux inode
diff --git a/fs/xfs/linux-2.6/xfs_iops.h b/fs/xfs/linux-2.6/xfs_iops.h
index 6a69a62..415de44 100644
--- a/fs/xfs/linux-2.6/xfs_iops.h
+++ b/fs/xfs/linux-2.6/xfs_iops.h
@@ -48,4 +48,8 @@
extern int xfs_ioctl(struct bhv_desc *, struct inode *, struct file *,
int, unsigned int, void __user *);
+struct xfs_inode;
+extern void xfs_ichgtime(struct xfs_inode *, int);
+extern void xfs_ichgtime_fast(struct xfs_inode *, struct inode *, int);
+
#endif /* __XFS_IOPS_H__ */
diff --git a/fs/xfs/linux-2.6/xfs_lrw.c b/fs/xfs/linux-2.6/xfs_lrw.c
index 3b5fabe..c04f0c0 100644
--- a/fs/xfs/linux-2.6/xfs_lrw.c
+++ b/fs/xfs/linux-2.6/xfs_lrw.c
@@ -302,7 +302,7 @@
xfs_iunlock(ip, XFS_IOLOCK_SHARED);
if (likely(!(ioflags & IO_INVIS)))
- xfs_ichgtime(ip, XFS_ICHGTIME_ACC);
+ xfs_ichgtime_fast(ip, inode, XFS_ICHGTIME_ACC);
unlock_isem:
if (unlikely(ioflags & IO_ISDIRECT))
@@ -367,7 +367,7 @@
XFS_STATS_ADD(xs_read_bytes, ret);
if (likely(!(ioflags & IO_INVIS)))
- xfs_ichgtime(ip, XFS_ICHGTIME_ACC);
+ xfs_ichgtime_fast(ip, LINVFS_GET_IP(vp), XFS_ICHGTIME_ACC);
return ret;
}
@@ -732,15 +732,10 @@
}
}
- /*
- * On Linux, generic_file_write updates the times even if
- * no data is copied in so long as the write had a size.
- *
- * We must update xfs' times since revalidate will overcopy xfs.
- */
- if (!(ioflags & IO_INVIS)) {
- xfs_ichgtime(xip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
+ if (likely(!(ioflags & IO_INVIS))) {
inode_update_time(inode, 1);
+ xfs_ichgtime_fast(xip, inode,
+ XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
}
/*
diff --git a/fs/xfs/linux-2.6/xfs_vnode.h b/fs/xfs/linux-2.6/xfs_vnode.h
index 76a8ddd..ef1c65f 100644
--- a/fs/xfs/linux-2.6/xfs_vnode.h
+++ b/fs/xfs/linux-2.6/xfs_vnode.h
@@ -567,13 +567,6 @@
}
/*
- * Update modify/access/change times on the vnode
- */
-#define VN_MTIMESET(vp, tvp) (LINVFS_GET_IP(vp)->i_mtime = *(tvp))
-#define VN_ATIMESET(vp, tvp) (LINVFS_GET_IP(vp)->i_atime = *(tvp))
-#define VN_CTIMESET(vp, tvp) (LINVFS_GET_IP(vp)->i_ctime = *(tvp))
-
-/*
* Dealing with bad inodes
*/
static inline void vn_mark_bad(struct vnode *vp)
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 5bf7b70..a648cc8 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -3688,73 +3688,6 @@
return( 0 );
}
-/*
- * Change the requested timestamp in the given inode.
- * We don't lock across timestamp updates, and we don't log them but
- * we do record the fact that there is dirty information in core.
- *
- * NOTE -- callers MUST combine XFS_ICHGTIME_MOD or XFS_ICHGTIME_CHG
- * with XFS_ICHGTIME_ACC to be sure that access time
- * update will take. Calling first with XFS_ICHGTIME_ACC
- * and then XFS_ICHGTIME_MOD may fail to modify the access
- * timestamp if the filesystem is mounted noacctm.
- */
-void
-xfs_ichgtime(xfs_inode_t *ip,
- int flags)
-{
- timespec_t tv;
- vnode_t *vp = XFS_ITOV(ip);
- struct inode *inode = LINVFS_GET_IP(vp);
-
- /*
- * We're not supposed to change timestamps in readonly-mounted
- * filesystems. Throw it away if anyone asks us.
- */
- if (unlikely(vp->v_vfsp->vfs_flag & VFS_RDONLY))
- return;
-
- /*
- * Don't update access timestamps on reads if mounted "noatime"
- * Throw it away if anyone asks us.
- */
- if ((ip->i_mount->m_flags & XFS_MOUNT_NOATIME || IS_NOATIME(inode)) &&
- ((flags & (XFS_ICHGTIME_ACC|XFS_ICHGTIME_MOD|XFS_ICHGTIME_CHG))
- == XFS_ICHGTIME_ACC))
- return;
-
- nanotime(&tv);
- if (flags & XFS_ICHGTIME_MOD) {
- VN_MTIMESET(vp, &tv);
- ip->i_d.di_mtime.t_sec = (__int32_t)tv.tv_sec;
- ip->i_d.di_mtime.t_nsec = (__int32_t)tv.tv_nsec;
- }
- if (flags & XFS_ICHGTIME_ACC) {
- VN_ATIMESET(vp, &tv);
- ip->i_d.di_atime.t_sec = (__int32_t)tv.tv_sec;
- ip->i_d.di_atime.t_nsec = (__int32_t)tv.tv_nsec;
- }
- if (flags & XFS_ICHGTIME_CHG) {
- VN_CTIMESET(vp, &tv);
- ip->i_d.di_ctime.t_sec = (__int32_t)tv.tv_sec;
- ip->i_d.di_ctime.t_nsec = (__int32_t)tv.tv_nsec;
- }
-
- /*
- * We update the i_update_core field _after_ changing
- * the timestamps in order to coordinate properly with
- * xfs_iflush() so that we don't lose timestamp updates.
- * This keeps us from having to hold the inode lock
- * while doing this. We use the SYNCHRONIZE macro to
- * ensure that the compiler does not reorder the update
- * of i_update_core above the timestamp updates above.
- */
- SYNCHRONIZE();
- ip->i_update_core = 1;
- if (!(inode->i_state & I_LOCK))
- mark_inode_dirty_sync(inode);
-}
-
#ifdef XFS_ILOCK_TRACE
ktrace_t *xfs_ilock_trace_buf;