[RFC v1 08/11] vfs: enable hot data tracking

zwu.kernel
2012-09-17T07:19:45Z

Miscellaneous features that implement hot data tracking
and generally make the hot data functions a bit more friendly.

Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
---
fs/direct-io.c | 10 ++++++++++
include/linux/hot_track.h | 11 +++++++++++
mm/filemap.c | 8 ++++++++
mm/page-writeback.c | 21 +++++++++++++++++++++
mm/readahead.c | 9 +++++++++
5 files changed, 59 insertions(+), 0 deletions(-)

diff --git a/fs/direct-io.c b/fs/direct-io.c
index f86c720..74068e2 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -37,6 +37,7 @@
#include <linux/uio.h>
#include <linux/atomic.h>
#include <linux/prefetch.h>
+#include <linux/hot_track.h>

/*
* How many user pages to map in one call to get_user_pages(). This determines
@@ -1297,6 +1298,15 @@ __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
prefetch(bdev->bd_queue);
prefetch((char *)bdev->bd_queue + SMP_CACHE_BYTES);

+ /* Hot data tracking */
+ if (TRACK_THIS_INODE(iocb->ki_filp->f_mapping->host)
+ && iov_length(iov, nr_segs) > 0) {
+ hot_rb_update_freqs(iocb->ki_filp->f_mapping->host,
+ (u64)offset,
+ (u64)iov_length(iov, nr_segs),
+ rw & WRITE);
+ }
+
return do_blockdev_direct_IO(rw, iocb, inode, bdev, iov, offset,
nr_segs, get_block, end_io,
submit_io, flags);
diff --git a/include/linux/hot_track.h b/include/linux/hot_track.h
index bde61de..8bb9028 100644
--- a/include/linux/hot_track.h
+++ b/include/linux/hot_track.h
@@ -28,6 +28,14 @@
*/
#define HOT_MOUNT_HOT_TRACK (1 << 0)

+/* Hot data tracking -- guard macros */
+#define TRACKING_HOT_TRACK(root) \
+ (root->s_hotinfo.mount_opt & HOT_MOUNT_HOT_TRACK)
+
+#define TRACK_THIS_INODE(inode) \
+ ((TRACKING_HOT_TRACK(inode->i_sb)) && \
+ !(inode->i_flags & S_NOHOTDATATRACK))
+
/* kmem_cache pointers for slab caches */
extern struct kmem_cache *hot_hash_node_cache;

@@ -138,4 +146,7 @@ struct hot_info {
struct hot_hash_head heat_range_hl[HEAT_HASH_SIZE];
};

+extern void hot_rb_update_freqs(struct inode *inode,
+ u64 start, u64 len, int rw);
+
#endif /* _LINUX_HOTTRACK_H */
diff --git a/mm/filemap.c b/mm/filemap.c
index 3843445..784d027 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -33,6 +33,7 @@
#include <linux/hardirq.h> /* for BUG_ON(!in_atomic()) only */
#include <linux/memcontrol.h>
#include <linux/cleancache.h>
+#include <linux/hot_track.h>
#include "internal.h"

/*
@@ -1224,6 +1225,13 @@ readpage:
* PG_error will be set again if readpage fails.
*/
ClearPageError(page);
+
+ /* Hot data tracking */
+ if (TRACK_THIS_INODE(filp->f_mapping->host))
+ hot_rb_update_freqs(filp->f_mapping->host,
+ (u64)page->index << PAGE_CACHE_SHIFT,
+ PAGE_CACHE_SIZE, 0);
+
/* Start the actual read. The read will unlock the page. */
error = mapping->a_ops->readpage(filp, page);

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 5ad5ce2..4e83e68 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -35,6 +35,7 @@
#include <linux/buffer_head.h> /* __set_page_dirty_buffers */
#include <linux/pagevec.h>
#include <linux/timer.h>
+#include <linux/hot_track.h>
#include <trace/events/writeback.h>

/*
@@ -1895,13 +1896,33 @@ EXPORT_SYMBOL(generic_writepages);
int do_writepages(struct address_space *mapping, struct writeback_control *wbc)
{
int ret;
+ pgoff_t start = 0;
+ u64 prev_count = 0, count = 0;

if (wbc->nr_to_write <= 0)
return 0;
+
+ /* Hot data tracking */
+ if (TRACK_THIS_INODE(mapping->host)
+ && wbc->range_cyclic) {
+ start = mapping->writeback_index << PAGE_CACHE_SHIFT;
+ prev_count = (u64)wbc->nr_to_write;
+ }
+
if (mapping->a_ops->writepages)
ret = mapping->a_ops->writepages(mapping, wbc);
else
ret = generic_writepages(mapping, wbc);
+
+ /* Hot data tracking */
+ if (TRACK_THIS_INODE(mapping->host)
+ && wbc->range_cyclic) {
+ count = prev_count - (u64)wbc->nr_to_write;
+ if (count)
+ hot_rb_update_freqs(mapping->host, (u64)start,
+ count * PAGE_CACHE_SIZE, 1);
+ }
+
return ret;
}

diff --git a/mm/readahead.c b/mm/readahead.c
index ea8f8fa..c204f2b 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -19,6 +19,7 @@
#include <linux/pagemap.h>
#include <linux/syscalls.h>
#include <linux/file.h>
+#include <linux/hot_track.h>

/*
* Initialise a struct file's readahead state. Assumes that the caller has
@@ -138,6 +139,14 @@ static int read_pages(struct address_space *mapping, struct file *filp,
out:
blk_finish_plug(&plug);

+ /* Hot data tracking */
+ if (TRACK_THIS_INODE(mapping->host) && nr_pages > 0) {
+ u64 start = (u64)(list_entry(pages->prev,
+ struct page, lru)->index) << PAGE_CACHE_SHIFT;
+ hot_rb_update_freqs(mapping->host, start,
+ (u64)nr_pages * PAGE_CACHE_SIZE, 0);
+ }
+
return ret;
}

--
1.7.6.5