linux/fs/btrfs
Chris Mason b765ead57d Btrfs: keep processing bios for a given bdev if our proc is batching
Btrfs uses async helper threads to submit write bios so the checksumming
helper threads don't block on the disk.

The submit bio threads may process bios for more than one block device,
so when they find one device congested they try to move on to other
devices instead of blocking in get_request_wait for one device.

This does a pretty good job of keeping multiple devices busy, but the
congested flag has a number of problems.  A congested device may still
give you a request, and other procs that aren't backing off the congested
device may starve you out.

This commit uses the io_context stored in current to decide if our process
has been made a batching process by the block layer.  If so, it keeps
sending IO down for at least one batch.  This helps make sure we do
a good amount of work each time we visit a bdev, and avoids large IO
stalls in multi-device workloads.

It's also very ugly.  A better solution is in the works with Jens Axboe.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-03 10:27:10 -04:00
..
acl.c Btrfs: Fix checkpatch.pl warnings 2009-01-05 21:25:51 -05:00
async-thread.c Btrfs: async threads should try harder to find work 2009-02-04 09:23:24 -05:00
async-thread.h Btrfs: Add ordered async work queues 2008-11-06 22:03:00 -05:00
btrfs_inode.h Btrfs: add extra flushing for renames and truncates 2009-03-31 14:27:58 -04:00
compat.h Btrfs: drop remaining LINUX_KERNEL_VERSION checks and compat code 2009-01-06 09:38:55 -05:00
compression.c Btrfs: removed unused #include <version.h>'s 2009-01-21 10:49:16 -05:00
compression.h Btrfs: Add zlib compression support 2008-10-29 14:49:59 -04:00
crc32c.h Btrfs: Drop the hardware crc32c asm code 2009-01-07 19:56:59 -05:00
ctree.c Btrfs: limit balancing work while flushing delayed refs 2009-03-24 16:14:51 -04:00
ctree.h Btrfs: add extra flushing for renames and truncates 2009-03-31 14:27:58 -04:00
delayed-ref.c Btrfs: make sure btrfs_update_delayed_ref doesn't increase ref_mod 2009-03-25 09:55:11 -04:00
delayed-ref.h Btrfs: make sure btrfs_update_delayed_ref doesn't increase ref_mod 2009-03-25 09:55:11 -04:00
dir-item.c Btrfs: leave btree locks spinning more often 2009-03-24 16:14:28 -04:00
disk-io.c Btrfs: add extra flushing for renames and truncates 2009-03-31 14:27:58 -04:00
disk-io.h Btrfs: leave btree locks spinning more often 2009-03-24 16:14:28 -04:00
export.c Btrfs: Fix checkpatch.pl warnings 2009-01-05 21:25:51 -05:00
export.h NFS support for btrfs - v3 2008-09-25 11:04:06 -04:00
extent_io.c Btrfs: leave btree locks spinning more often 2009-03-24 16:14:28 -04:00
extent_io.h Btrfs: leave btree locks spinning more often 2009-03-24 16:14:28 -04:00
extent_map.c Btrfs: removed unused #include <version.h>'s 2009-01-21 10:49:16 -05:00
extent_map.h Btrfs: Fix csum error for compressed data 2008-11-10 07:34:43 -05:00
extent-tree.c Btrfs: try to free metadata pages when we free btree blocks 2009-03-31 14:27:58 -04:00
file-item.c Btrfs: leave btree locks spinning more often 2009-03-24 16:14:28 -04:00
file.c Btrfs: add extra flushing for renames and truncates 2009-03-31 14:27:58 -04:00
free-space-cache.c Btrfs: Fix checkpatch.pl warnings 2009-01-05 21:25:51 -05:00
hash.h Switch btrfs_name_hash() to crc32c 2008-09-25 11:04:06 -04:00
inode-item.c Btrfs: leave btree locks spinning more often 2009-03-24 16:14:28 -04:00
inode-map.c Btrfs: remove btrfs_init_path 2009-02-12 14:11:25 -05:00
inode.c Btrfs: add extra flushing for renames and truncates 2009-03-31 14:27:58 -04:00
ioctl.c Btrfs: add better -ENOSPC handling 2009-02-20 11:00:09 -05:00
ioctl.h Btrfs: fix ioctl arg size (userland incompatible change!) 2009-01-16 11:59:08 -05:00
Kconfig Btrfs: make btrfs acls selectable 2009-02-04 09:28:28 -05:00
locking.c Btrfs: leave btree locks spinning more often 2009-03-24 16:14:28 -04:00
locking.h Btrfs: fix spinlock assertions on UP systems 2009-03-09 11:45:38 -04:00
Makefile Btrfs: do extent allocation and reference count updates in the background 2009-03-24 16:14:25 -04:00
ordered-data.c Btrfs: add extra flushing for renames and truncates 2009-03-31 14:27:58 -04:00
ordered-data.h Btrfs: add extra flushing for renames and truncates 2009-03-31 14:27:58 -04:00
orphan.c Btrfs: Create orphan inode records to prevent lost files after a crash 2008-09-25 11:04:05 -04:00
print-tree.c Btrfs: Fix checkpatch.pl warnings 2009-01-05 21:25:51 -05:00
print-tree.h Btrfs: Create extent_buffer interface for large blocksizes 2008-09-25 11:03:56 -04:00
ref-cache.c Btrfs: Make btrfs_drop_snapshot work in larger and more efficient chunks 2009-02-04 09:27:02 -05:00
ref-cache.h Btrfs: Make btrfs_drop_snapshot work in larger and more efficient chunks 2009-02-04 09:27:02 -05:00
root-tree.c Btrfs: Fix checkpatch.pl warnings 2009-01-05 21:25:51 -05:00
struct-funcs.c Btrfs: Fix checkpatch.pl warnings 2009-01-05 21:25:51 -05:00
super.c Btrfs: don't clean old snapshots on sync(1) 2009-02-12 09:45:08 -05:00
sysfs.c Btrfs: Fix checkpatch.pl warnings 2009-01-05 21:25:51 -05:00
transaction.c Btrfs: add extra flushing for renames and truncates 2009-03-31 14:27:58 -04:00
transaction.h Btrfs: reduce stalls during transaction commit 2009-03-24 16:14:26 -04:00
tree-defrag.c Btrfs: do extent allocation and reference count updates in the background 2009-03-24 16:14:25 -04:00
tree-log.c Btrfs: optimize fsyncs on old files 2009-03-24 16:14:52 -04:00
tree-log.h Btrfs: tree logging unlink/rename fixes 2009-03-24 16:14:52 -04:00
version.h Update Btrfs files for in-kernel usage 2008-09-25 15:41:59 -04:00
version.sh Btrfs: Fixes for 2.6.28-rc API changes 2008-11-19 21:17:22 -05:00
volumes.c Btrfs: keep processing bios for a given bdev if our proc is batching 2009-04-03 10:27:10 -04:00
volumes.h Btrfs: shared seed device 2008-12-12 10:03:26 -05:00
xattr.c Btrfs: selinux support 2009-02-04 09:29:13 -05:00
xattr.h Btrfs: selinux support 2009-02-04 09:29:13 -05:00
zlib.c Btrfs: Fix checkpatch.pl warnings 2009-01-05 21:25:51 -05:00