Commit Graph

26 Commits

Author SHA1 Message Date
Dave Chinner
d808f617ad xfs: Don't issue buffer IO direct from AIL push V2
All buffers logged into the AIL are marked as delayed write.
When the AIL needs to push the buffer out, it issues an async write of the
buffer. This means that IO patterns are dependent on the order of
buffers in the AIL.

Instead of flushing the buffer, promote the buffer in the delayed
write list so that the next time the xfsbufd is run the buffer will
be flushed by the xfsbufd. Return the state to the xfsaild that the
buffer was promoted so that the xfsaild knows that it needs to cause
the xfsbufd to run to flush the buffers that were promoted.

Using the xfsbufd for issuing the IO allows us to dispatch all
buffer IO from the one queue. This means that we can make much more
enlightened decisions on what order to flush buffers to disk as
we don't have multiple places issuing IO. Optimisations to xfsbufd
will be in a future patch.

Version 2
- kill XFS_ITEM_FLUSHING as it is now unused.

Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-02-02 10:13:42 +11:00
Christoph Hellwig
a14a348bff xfs: cleanup up xfs_log_force calling conventions
Remove the XFS_LOG_FORCE argument which was always set, and the
XFS_LOG_URGE define, which was never used.

Split xfs_log_force into a two helpers - xfs_log_force which forces
the whole log, and xfs_log_force_lsn which forces up to the
specified LSN.  The underlying implementations already were entirely
separate, as were the users.

Also re-indent the new _xfs_log_force/_xfs_log_force which
previously had a weird coding style.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2010-01-21 13:44:49 -06:00
Dave Chinner
453eac8a9a xfs: Don't wake the aild once per second
Now that the AIL push algorithm is traversal safe, we don't need a
watchdog function in the xfsaild to catch pushes that fail to make
progress. Remove the watchdog timeout and make pushes purely driven
by demand. This will remove the once-per-second wakeup that is seen
when the filesystem is idle and make laptop power misers happy.

Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2010-01-15 15:32:46 -06:00
Nathaniel W. Turner
6c06f072c2 xfs: copy li_lsn before dropping AIL lock
Access to log items on the AIL is generally protected by m_ail_lock;
this is particularly needed when we're getting or setting the 64-bit
li_lsn on a 32-bit platform.  This patch fixes a couple places where we
were accessing the log item after dropping the AIL lock on 32-bit
machines.

This can result in a partially-zeroed log->l_tail_lsn if
xfs_trans_ail_delete is racing with xfs_trans_ail_update, and in at
least some cases, this can leave the l_tail_lsn with a zero cycle
number, which means xlog_space_left will think the log is full (unless
CONFIG_XFS_DEBUG is set, in which case we'll trip an ASSERT), leading to
processes stuck forever in xlog_grant_log_space.

Thanks to Adrian VanderSpek for first spotting the race potential and to
Dave Chinner for debug assistance.

Signed-off-by: Nathaniel W. Turner <nate@houseofnate.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2009-11-17 10:26:49 -06:00
Malcolm Parsons
9da096fd13 xfs: fix various typos
Signed-off-by: Malcolm Parsons <malcolm.parsons@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2009-03-29 09:55:42 +02:00
David Chinner
7ee49acfe5 [XFS] correctly select first log item to push
Under heavy metadata load we are seeing log hangs. The AIL has items in it
ready to be pushed, and they are within the push target window. However,
we are not pushing them when the last pushed LSN is less than the LSN of
the first log item on the AIL. This is a regression introduced by the AIL
push cursor modifications.

SGI-PV: 987246

SGI-Modid: xfs-linux-melb:xfs-kern:32409a

Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2008-10-30 18:26:51 +11:00
David Chinner
783a2f656f [XFS] Finish removing the mount pointer from the AIL API
Change all the remaining AIL API functions that are passed struct
xfs_mount pointers to pass pointers directly to the struct xfs_ail being
used. With this conversion, all external access to the AIL is via the
struct xfs_ail. Hence the operation and referencing of the AIL is almost
entirely independent of the xfs_mount that is using it - it is now much
more tightly tied to the log and the items it is tracking in the log than
it is tied to the xfs_mount.

SGI-PV: 988143

SGI-Modid: xfs-linux-melb:xfs-kern:32353a

Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
2008-10-30 17:39:58 +11:00
David Chinner
c7e8f26827 [XFS] Move the AIL lock into the struct xfs_ail
Bring the ail lock inside the struct xfs_ail. This means the AIL can be
entirely manipulated via the struct xfs_ail rather than needing both the
struct xfs_mount and the struct xfs_ail.

SGI-PV: 988143

SGI-Modid: xfs-linux-melb:xfs-kern:32350a

Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
2008-10-30 17:39:23 +11:00
David Chinner
5b00f14fbd [XFS] move the AIl traversal over to a consistent interface
With the new cursor interface, it makes sense to make all the traversing
code use the cursor interface and make the old one go away. This means
more of the AIL interfacing is done by passing struct xfs_ail pointers
around the place instead of struct xfs_mount pointers.

We can replace the use of xfs_trans_first_ail() in xfs_log_need_covered()
as it is only checking if the AIL is empty. We can do that with a call to
xfs_trans_ail_tail() instead, where a zero LSN returned indicates and
empty AIL...

SGI-PV: 988143

SGI-Modid: xfs-linux-melb:xfs-kern:32348a

Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
2008-10-30 17:39:00 +11:00
David Chinner
27d8d5fe0e [XFS] Use a cursor for AIL traversal.
To replace the current generation number ensuring sanity of the AIL
traversal, replace it with an external cursor that is linked to the AIL.

Basically, we store the next item in the cursor whenever we want to drop
the AIL lock to do something to the current item. When we regain the lock.
the current item may already be free, so we can't reference it, but the
next item in the traversal is already held in the cursor.

When we move or delete an object, we search all the active cursors and if
there is an item match we clear the cursor(s) that point to the object.
This forces the traversal to restart transparently.

We don't invalidate the cursor on insert because the cursor still points
to a valid item. If the intem is inserted between the current item and the
cursor it does not matter; the traversal is considered to be past the
insertion point so it will be picked up in the next traversal.

Hence traversal restarts pretty much disappear altogether with this method
of traversal, which should substantially reduce the overhead of pushing on
a busy AIL.

Version 2 o add restart logic o comment cursor interface o minor cleanups

SGI-PV: 988143

SGI-Modid: xfs-linux-melb:xfs-kern:32347a

Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
2008-10-30 17:38:39 +11:00
David Chinner
82fa901245 [XFS] Allocate the struct xfs_ail
Rather than embedding the struct xfs_ail in the struct xfs_mount, allocate
it during AIL initialisation. Add a back pointer to the struct xfs_ail so
that we can pass around the xfs_ail and still be able to access the
xfs_mount if need be. This is th first step involved in isolating the AIL
implementation from the surrounding filesystem code.

SGI-PV: 988143

SGI-Modid: xfs-linux-melb:xfs-kern:32346a

Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
2008-10-30 17:38:26 +11:00
Harvey Harrison
34a622b2e1 [XFS] replace remaining __FUNCTION__ occurrences
__FUNCTION__ is gcc-specific, use __func__

SGI-PV: 976035
SGI-Modid: xfs-linux-melb:xfs-kern:30775a

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-04-18 11:51:26 +10:00
Josef 'Jeff' Sipek
535f6b3735 [XFS] Replace custom AIL linked-list code with struct list_head
Replace the xfs_ail_entry_t with a struct list_head and clean the
surrounding code up. Also fixes a livelock in xfs_trans_first_push_ail()
by terminating the loop at the head of the list correctly.

SGI-PV: 978682
SGI-Modid: xfs-linux-melb:xfs-kern:30636a

Signed-off-by: Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-04-18 11:41:57 +10:00
David Chinner
92d9cd1059 [XFS] 977545 977545 977545 977545 977545 977545 xfsaild causing too many
wakeups

Idle state is not being detected properly by the xfsaild push code. The
current idle state is detected by an empty list which may never happen
with mostly idle filesystem or one using lazy superblock counters. A
single dirty item in the list that exists beyond the push target can
result repeated looping attempting to push up to the target because it
fails to check if the push target has been acheived or not.

Fix by considering a dirty list with everything past the target as an idle
state and set the timeout appropriately.

SGI-PV: 977545
SGI-Modid: xfs-linux-melb:xfs-kern:30532a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-03-06 16:38:17 +11:00
David Chinner
de08dbc197 [XFS] Make xfs_ail_check check less by default
Checking the entire AIL on every insert and remove is prohibitively
expensive - the sustained sequntial create rate on a single disk drops
from about 1800/s to 60/s because of this checking resulting in the
xfslogd becoming cpu bound.

By default on debug builds, only check the next and previous entries in
the list to ensure they are ordered correctly. If you really want, define
XFS_TRANS_DEBUG to use the old behaviour.

SGI-PV: 972759
SGI-Modid: xfs-linux-melb:xfs-kern:30372a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-02-07 18:23:05 +11:00
David Chinner
249a8c1124 [XFS] Move AIL pushing into it's own thread
When many hundreds to thousands of threads all try to do simultaneous
transactions and the log is in a tail-pushing situation (i.e. full), we
can get multiple threads walking the AIL list and contending on the AIL
lock.

The AIL push is, in effect, a simple I/O dispatch algorithm complicated by
the ordering constraints placed on it by the transaction subsystem. It
really does not need multiple threads to push on it - even when only a
single CPU is pushing the AIL, it can push the I/O out far faster that
pretty much any disk subsystem can handle.

So, to avoid contention problems stemming from multiple list walkers, move
the list walk off into another thread and simply provide a "target" to
push to. When a thread requires a push, it sets the target and wakes the
push thread, then goes to sleep waiting for the required amount of space
to become available in the log.

This mechanism should also be a lot fairer under heavy load as the waiters
will queue in arrival order, rather than queuing in "who completed a push
first" order.

Also, by moving the pushing to a separate thread we can do more
effectively overload detection and prevention as we can keep context from
loop iteration to loop iteration. That is, we can push only part of the
list each loop and not have to loop back to the start of the list every
time we run. This should also help by reducing the number of items we try
to lock and/or push items that we cannot move.

Note that this patch is not intended to solve the inefficiencies in the
AIL structure and the associated issues with extremely large list
contents. That needs to be addresses separately; parallel access would
cause problems to any new structure as well, so I'm only aiming to isolate
the structure from unbounded parallelism here.

SGI-PV: 972759
SGI-Modid: xfs-linux-melb:xfs-kern:30371a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-02-07 18:22:51 +11:00
Donald Douwsma
287f3dad14 [XFS] Unwrap AIL_LOCK
SGI-PV: 970382
SGI-Modid: xfs-linux-melb:xfs-kern:29739a

Signed-off-by: Donald Douwsma <donaldd@sgi.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2008-02-07 16:44:23 +11:00
David Chinner
da353b0d64 [XFS] Radix tree based inode caching
One of the perpetual scaling problems XFS has is indexing it's incore
inodes. We currently uses hashes and the default hash sizes chosen can
only ever be a tradeoff between memory consumption and the maximum
realistic size of the cache.

As a result, anyone who has millions of inodes cached on a filesystem
needs to tunes the size of the cache via the ihashsize mount option to
allow decent scalability with inode cache operations.

A further problem is the separate inode cluster hash, whose size is based
on the ihashsize but is smaller, and so under certain conditions (sparse
cluster cache population) this can become a limitation long before the
inode hash is causing issues.

The following patchset removes the inode hash and cluster hash and
replaces them with radix trees to avoid the scalability limitations of the
hashes. It also reduces the size of the inodes by 3 pointers....

SGI-PV: 969561
SGI-Modid: xfs-linux-melb:xfs-kern:29481a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-10-15 16:50:50 +10:00
Vlad Apostolov
7666ab5fb3 [XFS] Workaround log space issue by increasing XFS_TRANS_PUSH_AIL_RESTARTS
SGI-PV: 959264
SGI-Modid: xfs-linux-melb:xfs-kern:27750a

Signed-off-by: Vlad Apostolov <vapo@sgi.com>
Signed-off-by: David Chatterton <chatz@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-02-10 18:35:52 +11:00
Josh Triplett
22d91f65d5 [XFS] Add lock annotations to xfs_trans_update_ail and
xfs_trans_delete_ail

xfs_trans_update_ail and xfs_trans_delete_ail get called with the AIL lock
held, and release it. Add lock annotations to these two functions so that
sparse can check callers for lock pairing, and so that sparse will not
complain about these functions since they intentionally use locks in this
manner.

SGI-PV: 954580
SGI-Modid: xfs-linux-melb:xfs-kern:26807a

Signed-off-by: Josh Triplett <josh@freedesktop.org>
Signed-off-by: Nathan Scott <nathans@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2006-09-28 11:04:07 +10:00
Nathan Scott
f6c2d1fa63 [XFS] Remove version 1 directory code. Never functioned on Linux, just
pure bloat.

SGI-PV: 952969
SGI-Modid: xfs-linux-melb:xfs-kern:26251a

Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-06-20 13:04:51 +10:00
Nathan Scott
7d04a335b6 [XFS] Shutdown the filesystem if all device paths have gone. Made
shutdown vop flags consistent with sync vop flags declarations too.

SGI-PV: 939911
SGI-Modid: xfs-linux-melb:xfs-kern:26096a

Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-06-09 14:58:38 +10:00
Nathan Scott
7b71876980 [XFS] Update license/copyright notices to match the prefered SGI
boilerplate.

SGI-PV: 913862
SGI-Modid: xfs-linux:xfs-kern:23903a

Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-11-02 14:58:39 +11:00
Nathan Scott
a844f4510d [XFS] Remove xfs_macros.c, xfs_macros.h, rework headers a whole lot.
SGI-PV: 943122
SGI-Modid: xfs-linux:xfs-kern:23901a

Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-11-02 14:38:42 +11:00
Tim Shimmin
6f948fbd44 [XFS] Need to unlock the AIL before calling xfs_force_shutdown() because
when it goes to force out the log, and get the tail lsn, it will want to
get the AIL lock.

SGI-PV: 940076
SGI-Modid: xfs-linux:xfs-kern:23260a

Signed-off-by: Tim Shimmin <tes@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-09-02 16:52:55 +10:00
Linus Torvalds
1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00