cgroup writeback support needs to keep track of the sum of avg_write_bandwidth of all wb's (bdi_writeback's) with dirty inodes to distribute write workload. This patch adds bdi->tot_write_bandwidth and updates inode_wb_list_move_locked(), inode_wb_list_del_locked() and wb_update_write_bandwidth() to adjust it as wb's gain and lose dirty inodes and its avg_write_bandwidth gets updated. As the update events are not synchronized with each other, bdi->tot_write_bandwidth is an atomic_long_t. Signed-off-by: Tejun Heo <tj@xxxxxxxxxx> Cc: Jens Axboe <axboe@xxxxxxxxx> Cc: Jan Kara <jack@xxxxxxx> --- fs/fs-writeback.c | 7 ++++++- include/linux/backing-dev-defs.h | 2 ++ mm/page-writeback.c | 3 +++ 3 files changed, 11 insertions(+), 1 deletion(-) diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 1718f5f..d41728b 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -312,6 +312,8 @@ static bool inode_wb_list_move_locked(struct inode *inode, return false; } else { set_bit(WB_has_dirty_io, &wb->state); + atomic_long_add(wb->avg_write_bandwidth, + &wb->bdi->tot_write_bandwidth); return true; } } @@ -332,8 +334,11 @@ static void inode_wb_list_del_locked(struct inode *inode, list_del_init(&inode->i_wb_list); if (wb_has_dirty_io(wb) && list_empty(&wb->b_dirty) && - list_empty(&wb->b_io) && list_empty(&wb->b_more_io)) + list_empty(&wb->b_io) && list_empty(&wb->b_more_io)) { clear_bit(WB_has_dirty_io, &wb->state); + atomic_long_sub(wb->avg_write_bandwidth, + &wb->bdi->tot_write_bandwidth); + } } /* diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h index d1c0bf4..e1f5f08 100644 --- a/include/linux/backing-dev-defs.h +++ b/include/linux/backing-dev-defs.h @@ -100,6 +100,8 @@ struct backing_dev_info { unsigned int min_ratio; unsigned int max_ratio, max_prop_frac; + atomic_long_t tot_write_bandwidth; /* sum of active avg_write_bw */ + struct bdi_writeback wb; /* the root writeback info for this bdi */ #ifdef CONFIG_CGROUP_WRITEBACK struct radix_tree_root cgwb_tree; /* radix tree of !root cgroup wbs */ diff --git a/mm/page-writeback.c b/mm/page-writeback.c index b115a57..176d0fb 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -879,6 +879,9 @@ static void wb_update_write_bandwidth(struct bdi_writeback *wb, avg += (old - avg) >> 3; out: + if (wb_has_dirty_io(wb)) + atomic_long_add(avg - wb->avg_write_bandwidth, + &wb->bdi->tot_write_bandwidth); wb->write_bandwidth = bw; wb->avg_write_bandwidth = avg; } -- 2.1.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>