[PATCH 13/18] writeback: remove writeback_control.more_io

Wu Fengguang
2011-05-19T21:57:24Z

[-- Attachment #1: writeback-kill-more_io.patch --]
[-- Type: text/plain, Size: 4431 bytes --]

When wbc.more_io was first introduced, it indicates whether there are
at least one superblock whose s_more_io contains more IO work. Now with
the per-bdi writeback, it can be replaced with a simple b_more_io test.

Acked-by: Jan Kara <jack@suse.cz>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
---
fs/fs-writeback.c | 9 ++-------
include/linux/writeback.h | 1 -
include/trace/events/ext4.h | 6 ++----
include/trace/events/writeback.h | 5 +----
4 files changed, 5 insertions(+), 16 deletions(-)

--- linux-next.orig/fs/fs-writeback.c 2011-05-20 05:12:42.000000000 +0800
+++ linux-next/fs/fs-writeback.c 2011-05-20 05:12:45.000000000 +0800
@@ -560,12 +560,8 @@ static int writeback_sb_inodes(struct su
iput(inode);
cond_resched();
spin_lock(&wb->list_lock);
- if (wbc->nr_to_write <= 0) {
- wbc->more_io = 1;
+ if (wbc->nr_to_write <= 0)
return 1;
- }
- if (!list_empty(&wb->b_more_io))
- wbc->more_io = 1;
}
/* b_io is empty */
return 1;
@@ -708,7 +704,6 @@ static long wb_writeback(struct bdi_writ
wbc.older_than_this = &oldest_jif;
}

- wbc.more_io = 0;
wbc.nr_to_write = write_chunk;
wbc.pages_skipped = 0;
wbc.inodes_cleaned = 0;
@@ -754,7 +749,7 @@ retry:
/*
* No more inodes for IO, bail
*/
- if (!wbc.more_io)
+ if (list_empty(&wb->b_more_io))
break;
/*
* Nothing written. Wait for some inode to
--- linux-next.orig/include/linux/writeback.h 2011-05-20 05:12:42.000000000 +0800
+++ linux-next/include/linux/writeback.h 2011-05-20 05:12:45.000000000 +0800
@@ -46,7 +46,6 @@ struct writeback_control {
unsigned tagged_writepages:1; /* tag-and-write to avoid livelock */
unsigned for_reclaim:1; /* Invoked from the page allocator */
unsigned range_cyclic:1; /* range_start is cyclic */
- unsigned more_io:1; /* more io to be dispatched */
};

/*
--- linux-next.orig/include/trace/events/writeback.h 2011-05-20 05:08:25.000000000 +0800
+++ linux-next/include/trace/events/writeback.h 2011-05-20 05:12:45.000000000 +0800
@@ -101,7 +101,6 @@ DECLARE_EVENT_CLASS(wbc_class,
__field(int, for_background)
__field(int, for_reclaim)
__field(int, range_cyclic)
- __field(int, more_io)
__field(unsigned long, older_than_this)
__field(long, range_start)
__field(long, range_end)
@@ -116,7 +115,6 @@ DECLARE_EVENT_CLASS(wbc_class,
__entry->for_background = wbc->for_background;
__entry->for_reclaim = wbc->for_reclaim;
__entry->range_cyclic = wbc->range_cyclic;
- __entry->more_io = wbc->more_io;
__entry->older_than_this = wbc->older_than_this ?
*wbc->older_than_this : 0;
__entry->range_start = (long)wbc->range_start;
@@ -124,7 +122,7 @@ DECLARE_EVENT_CLASS(wbc_class,
),

TP_printk("bdi %s: towrt=%ld skip=%ld mode=%d kupd=%d "
- "bgrd=%d reclm=%d cyclic=%d more=%d older=0x%lx "
+ "bgrd=%d reclm=%d cyclic=%d older=0x%lx "
"start=0x%lx end=0x%lx",
__entry->name,
__entry->nr_to_write,
@@ -134,7 +132,6 @@ DECLARE_EVENT_CLASS(wbc_class,
__entry->for_background,
__entry->for_reclaim,
__entry->range_cyclic,
- __entry->more_io,
__entry->older_than_this,
__entry->range_start,
__entry->range_end)
--- linux-next.orig/include/trace/events/ext4.h 2011-05-20 05:08:25.000000000 +0800
+++ linux-next/include/trace/events/ext4.h 2011-05-20 05:12:45.000000000 +0800
@@ -404,7 +404,6 @@ TRACE_EVENT(ext4_da_writepages_result,
__field( int, pages_written )
__field( long, pages_skipped )
__field( int, sync_mode )
- __field( char, more_io )
__field( pgoff_t, writeback_index )
),

@@ -415,16 +414,15 @@ TRACE_EVENT(ext4_da_writepages_result,
__entry->pages_written = pages_written;
__entry->pages_skipped = wbc->pages_skipped;
__entry->sync_mode = wbc->sync_mode;
- __entry->more_io = wbc->more_io;
__entry->writeback_index = inode->i_mapping->writeback_index;
),

TP_printk("dev %d,%d ino %lu ret %d pages_written %d pages_skipped %ld "
- " more_io %d sync_mode %d writeback_index %lu",
+ "sync_mode %d writeback_index %lu",
MAJOR(__entry->dev), MINOR(__entry->dev),
(unsigned long) __entry->ino, __entry->ret,
__entry->pages_written, __entry->pages_skipped,
- __entry->more_io, __entry->sync_mode,
+ __entry->sync_mode,
(unsigned long) __entry->writeback_index)
);