Re: [PATCH] Btrfs: limit thread pool size when remounting
From: David Sterba <hidden>
Date: 2012-09-25 11:39:44
On Tue, Sep 25, 2012 at 02:48:33PM +0800, Liu Bo wrote:
quoted hunk ↗ jump to hunk
--- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c@@ -1158,17 +1158,20 @@ static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info, printk(KERN_INFO "btrfs: resize thread pool %d -> %d\n", old_pool_size, new_pool_size); - btrfs_set_max_workers(&fs_info->generic_worker, new_pool_size); + btrfs_set_max_workers(&fs_info->generic_worker, min(1, new_pool_size));
How could new_pool_size be < 1 ? There's a check in super.c to pick only values > 0
btrfs_set_max_workers(&fs_info->workers, new_pool_size); btrfs_set_max_workers(&fs_info->delalloc_workers, new_pool_size); - btrfs_set_max_workers(&fs_info->submit_workers, new_pool_size); - btrfs_set_max_workers(&fs_info->caching_workers, new_pool_size); - btrfs_set_max_workers(&fs_info->fixup_workers, new_pool_size); + btrfs_set_max_workers(&fs_info->submit_workers, + min_t(u64, fs_info->fs_devices->num_devices, + new_pool_size));
This ask for update also when a new device is added/removed.
+ btrfs_set_max_workers(&fs_info->caching_workers, min(2, new_pool_size)); + btrfs_set_max_workers(&fs_info->fixup_workers, min(1, new_pool_size));
Same as above, is it expected to be < 1 ?
btrfs_set_max_workers(&fs_info->endio_workers, new_pool_size); btrfs_set_max_workers(&fs_info->endio_meta_workers, new_pool_size); btrfs_set_max_workers(&fs_info->endio_meta_write_workers, new_pool_size); btrfs_set_max_workers(&fs_info->endio_write_workers, new_pool_size); - btrfs_set_max_workers(&fs_info->endio_freespace_worker, new_pool_size); + btrfs_set_max_workers(&fs_info->endio_freespace_worker, + min(1, new_pool_size));
Not sure, do we actually need more than 1 free space worker?
btrfs_set_max_workers(&fs_info->delayed_workers, new_pool_size); btrfs_set_max_workers(&fs_info->readahead_workers, new_pool_size); btrfs_set_max_workers(&fs_info->scrub_workers, new_pool_size);