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authorChris Mason <chris.mason@oracle.com>2008-06-11 21:47:56 -0400
committerChris Mason <chris.mason@oracle.com>2008-09-25 11:04:03 -0400
commit4543df7ecc8ae4928c1e51d6e7dc188d650abee4 (patch)
treec0e32d2bdaaf26f6819f5f034ed8f1679d23109f /fs/btrfs/disk-io.c
parent35d8ba66294ff2a53c17337a1aa1ff6739492f41 (diff)
Btrfs: Add a mount option to control worker thread pool size
mount -o thread_pool_size changes the default, which is min(num_cpus + 2, 8). Larger thread pools would make more sense on very large disk arrays. This mount option controls the max size of each thread pool. There are multiple thread pools, so the total worker count will be larger than the mount option. Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs/disk-io.c')
-rw-r--r--fs/btrfs/disk-io.c30
1 files changed, 15 insertions, 15 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 98ff4fbcb38..c6a710a668c 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1117,6 +1117,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
GFP_NOFS);
int ret;
int err = -EINVAL;
+
struct btrfs_super_block *disk_super;
if (!extent_root || !tree_root || !fs_info) {
@@ -1148,6 +1149,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
fs_info->btree_inode = new_inode(sb);
fs_info->btree_inode->i_ino = 1;
fs_info->btree_inode->i_nlink = 1;
+ fs_info->thread_pool_size = min(num_online_cpus() + 2, 8);
sb->s_blocksize = 4096;
sb->s_blocksize_bits = blksize_bits(4096);
@@ -1195,19 +1197,6 @@ struct btrfs_root *open_ctree(struct super_block *sb,
mutex_init(&fs_info->trans_mutex);
mutex_init(&fs_info->fs_mutex);
- /* we need to start all the end_io workers up front because the
- * queue work function gets called at interrupt time. The endio
- * workers don't normally start IO, so some number of them <= the
- * number of cpus is fine. They handle checksumming after a read.
- *
- * The other worker threads do start IO, so the max is larger than
- * the number of CPUs. FIXME, tune this for huge machines
- */
- btrfs_init_workers(&fs_info->workers, num_online_cpus() * 2);
- btrfs_init_workers(&fs_info->endio_workers, num_online_cpus());
- btrfs_start_workers(&fs_info->workers, 1);
- btrfs_start_workers(&fs_info->endio_workers, num_online_cpus());
-
#if 0
ret = add_hasher(fs_info, "crc32c");
if (ret) {
@@ -1238,6 +1227,17 @@ struct btrfs_root *open_ctree(struct super_block *sb,
if (err)
goto fail_sb_buffer;
+ /*
+ * we need to start all the end_io workers up front because the
+ * queue work function gets called at interrupt time, and so it
+ * cannot dynamically grow.
+ */
+ btrfs_init_workers(&fs_info->workers, fs_info->thread_pool_size);
+ btrfs_init_workers(&fs_info->endio_workers, fs_info->thread_pool_size);
+ btrfs_start_workers(&fs_info->workers, 1);
+ btrfs_start_workers(&fs_info->endio_workers, fs_info->thread_pool_size);
+
+
err = -EINVAL;
if (btrfs_super_num_devices(disk_super) > fs_devices->open_devices) {
printk("Btrfs: wanted %llu devices, but found %llu\n",
@@ -1341,10 +1341,10 @@ fail_sys_array:
mutex_unlock(&fs_info->fs_mutex);
fail_sb_buffer:
extent_io_tree_empty_lru(&BTRFS_I(fs_info->btree_inode)->io_tree);
-fail_iput:
- iput(fs_info->btree_inode);
btrfs_stop_workers(&fs_info->workers);
btrfs_stop_workers(&fs_info->endio_workers);
+fail_iput:
+ iput(fs_info->btree_inode);
fail:
btrfs_close_devices(fs_info->fs_devices);
btrfs_mapping_tree_free(&fs_info->mapping_tree);