writeback: remove writeback_control.more_io

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>

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index d0553f3..f43c479 100644 (file)
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -560,12 +560,8 @@ static int writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb,
                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_writeback *wb,
                        wbc.older_than_this = &oldest_jif;
                }
 
-               wbc.more_io = 0;
                wbc.nr_to_write = write_chunk;
                wbc.pages_skipped = 0;
                wbc.inodes_written = 0;
@@ -740,7 +735,7 @@ static long wb_writeback(struct bdi_writeback *wb,
                /*
                 * 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

diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index d8e96a4..8797b20 100644 (file)
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -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 */
 };
 
 /*

diff --git a/include/trace/events/ext4.h b/include/trace/events/ext4.h
index e09592d..b225d0d 100644 (file)
--- a/include/trace/events/ext4.h
+++ b/include/trace/events/ext4.h
@@ -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)
 );
 

diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h
index 4e249b9..b2cfac5 100644 (file)
--- a/include/trace/events/writeback.h
+++ b/include/trace/events/writeback.h
@@ -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)