Commit Graph

260 Commits

Author SHA1 Message Date
Jens Axboe bb37b94c68 [BLOCK] Cleanup unused variable passing
- ->init_queue() does not need the elevator passed in
- ->put_request() is a hot path and need not have the queue passed in
- cfq_update_io_seektime() does not need cfqd passed in

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2006-12-01 10:42:33 +01:00
Mike Christie 0e75f9063f [PATCH] block: support larger block pc requests
This patch modifies blk_rq_map/unmap_user() and the cdrom and scsi_ioctl.c
users so that it supports requests larger than bio by chaining them together.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2006-12-01 10:40:55 +01:00
Olaf Kirch be1c63411a [PATCH] blktrace: add timestamp message
This adds a new timestamp message to blktrace, giving the timeofday when
we starting tracing. This helps user space correlate block trace events
with eg an application strace.

This requires a (compatible) update to blkparse. The changed blkparse
is still able to process traces generated by older kernels, and older
versions of blkparse should silently ignore the new records (because
they have a pid of 0).

Signed-off-by: Olaf Kirch <okir@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2006-12-01 10:39:12 +01:00
James Bottomley 0bd2af4683 Merge ../scsi-rc-fixes-2.6 2006-11-22 12:06:44 -06:00
David Howells 65f27f3844 WorkStruct: Pass the work_struct pointer instead of context data
Pass the work_struct pointer to the work function rather than context data.
The work function can use container_of() to work out the data.

For the cases where the container of the work_struct may go away the moment the
pending bit is cleared, it is made possible to defer the release of the
structure by deferring the clearing of the pending bit.

To make this work, an extra flag is introduced into the management side of the
work_struct.  This governs auto-release of the structure upon execution.

Ordinarily, the work queue executor would release the work_struct for further
scheduling or deallocation by clearing the pending bit prior to jumping to the
work function.  This means that, unless the driver makes some guarantee itself
that the work_struct won't go away, the work function may not access anything
else in the work_struct or its container lest they be deallocated..  This is a
problem if the auxiliary data is taken away (as done by the last patch).

However, if the pending bit is *not* cleared before jumping to the work
function, then the work function *may* access the work_struct and its container
with no problems.  But then the work function must itself release the
work_struct by calling work_release().

In most cases, automatic release is fine, so this is the default.  Special
initiators exist for the non-auto-release case (ending in _NAR).


Signed-Off-By: David Howells <dhowells@redhat.com>
2006-11-22 14:55:48 +00:00
Tejun Heo 097b8457da [PATCH] scsi: clear garbage after CDBs on SG_IO
ATAPI devices transfer fixed number of bytes for CDBs (12 or 16).  Some
ATAPI devices choke when shorter CDB is used and the left bytes contain
garbage.  Block SG_IO cleared left bytes but SCSI SG_IO didn't.  This patch
makes SCSI SG_IO clear it and simplify CDB clearing in block SG_IO.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Mathieu Fluhr <mfluhr@nero.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Douglas Gilbert <dougg@torque.net>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Cc: <stable@kernel.org>
Acked-by: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-11-16 11:43:38 -08:00
Hannes Reinecke 85e04e371b [SCSI] block: convert jiffies to msecs in scsi_ioctl()
Use the proper conversion function for convert jiffies to msecs in
sg_io().

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-11-15 17:57:33 -06:00
Jens Axboe 616e8a091a [PATCH] Fix bad data direction in SG_IO
Contrary to what the name misleads you to believe, SG_DXFER_TO_FROM_DEV
is really just a normal read seen from the device side.

This patch fixes http://lkml.org/lkml/2006/10/13/100

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-11-13 09:47:00 -08:00
Andrew Morton df66b8552b [PATCH] tidy "md: check bio address after mapping through partitions"
Neil's xterms are too wide.

Cc: Neil Brown <neilb@cse.unsw.edu.au>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-11-03 12:27:55 -08:00
Jens Axboe 5fccbf61be [PATCH] CFQ: request <-> request merging rr_list fixup
In very rare circumstances would we be pruning a merged request and at
the same time delete the implicated cfqq from the rr_list, and not readd
it when the merged request got added. This could cause io stalls until
that process issued io again.

Fix it up by putting the rr_list add handling into cfq_add_rq_rb(),
identical to how pruning is handled in cfq_del_rq_rb(). This fixes a
hang reproducible with fsx-linux.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-31 08:12:45 -08:00
NeilBrown 5ddfe9691c [PATCH] md: check bio address after mapping through partitions.
Partitions are not limited to live within a device.  So we should range
check after partition mapping.

Note that 'maxsector' was being used for two different things.  I have
split off the second usage into 'old_sector' so that maxsector can be still
be used for it's primary usage later in the function.

Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-31 08:07:01 -08:00
Jens Axboe c1b707d253 [PATCH] CFQ: bad locking in changed_ioprio()
When the ioprio code recently got juggled a bit, a bug was introduced.
changed_ioprio() is no longer called with interrupts disabled, so using
plain spin_lock() on the queue_lock is a bug.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-30 11:01:50 -08:00
Jens Axboe 0261d6886e [PATCH] CFQ: use irq safe locking in cfq_cic_link()
If cfq_set_request() is called for a new process AND a non-fs io
request (so that __GFP_WAIT may not be set), cfq_cic_link() may
use spin_lock_irq() and spin_unlock_irq() with interrupts already
disabled.

Fix is to always use irq safe locking in cfq_cic_link()

Acked-By: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-30 10:21:58 -08:00
Andrew Morton 3fcfab16c5 [PATCH] separate bdi congestion functions from queue congestion functions
Separate out the concept of "queue congestion" from "backing-dev congestion".
Congestion is a backing-dev concept, not a queue concept.

The blk_* congestion functions are retained, as wrappers around the core
backing-dev congestion functions.

This proper layering is needed so that NFS can cleanly use the congestion
functions, and so that CONFIG_BLOCK=n actually links.

Cc: "Thomas Maier" <balagi@justmail.de>
Cc: "Jens Axboe" <jens.axboe@oracle.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: David Howells <dhowells@redhat.com>
Cc: Peter Osterlund <petero2@telia.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-20 10:26:35 -07:00
Thomas Maier 79e2de4bc5 [PATCH] export clear_queue_congested and set_queue_congested
Export the clear_queue_congested() and set_queue_congested() functions
located in ll_rw_blk.c

The functions are renamed to blk_clear_queue_congested() and
blk_set_queue_congested().

(needed in the pktcdvd driver's bio write congestion control)

Signed-off-by: Thomas Maier <balagi@justmail.de>
Cc: Peter Osterlund <petero2@telia.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-20 10:26:35 -07:00
Vasily Tarasov c584164224 [PATCH] block layer: elv_iosched_show should get elv_list_lock
elv_iosched_show function iterates other elv_list, hence
elv_list_lock should be got.

Signed-off-by: Vasily Tarasov <vtaras@openvz.org>
Signed-off-by: Vasily Tarasov <jens.axboe@oracle.com>
2006-10-12 15:08:51 +02:00
Vasily Tarasov a22b169df1 [PATCH] block layer: elevator_find function cleanup
We can easily produce search through the elevator list
without introducing additional elevator_type variable.

Signed-off-by: Vasily Tarasov <vtaras@openvz.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2006-10-12 15:08:51 +02:00
David C Somayajulu f583f4924d [PATCH] helper function for retrieving scsi_cmd given host based block layer tag
This was necessitated by the need for a function to get back
to a scsi_cmnd, when an hba the posts its (corresponding) completion
interrupt with a block layer tag as its reference.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: David Somayajulu <david.somayajulu@qlogic.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2006-10-04 19:32:09 +02:00
Alasdair G Kergon 7006f6eca8 [PATCH] dm: export blkdev_driver_ioctl
Export blkdev_driver_ioctl for device-mapper.

If we get as far as the device-mapper ioctl handler, we know the ioctl is not
a standard block layer BLK* one, so we don't need to check for them a second
time and can call blkdev_driver_ioctl() directly.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03 08:04:13 -07:00
Peter Zijlstra 6e9a4738c9 [PATCH] completions: lockdep annotate on stack completions
All on stack DECLARE_COMPLETIONs should be replaced by:
DECLARE_COMPLETION_ONSTACK

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:24 -07:00
Jens Axboe 51d7513a8a [PATCH] Only enable CONFIG_BLOCK option for embedded
It's too easy for people to shoot themselves in the foot, and it
only makes sense for embedded folks anyway.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-09-30 21:14:05 +02:00
Jens Axboe 059af497c2 [PATCH] blk_queue_start_tag() shared map race fix
If we share the tag map between two or more queues, then we cannot
use __set_bit() to set the bit. In fact we need to make sure we
atomically acquire this tag, so loop using test_and_set_bit() to
protect from that.

Noticed by Mike Christie <michaelc@cs.wisc.edu>

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-09-30 20:52:34 +02:00
Jens Axboe 0fe2347957 [PATCH] Update axboe@suse.de email address
As people often look for the copyright in files to see who to mail,
update the link to a neutral one.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-09-30 20:52:34 +02:00
David Howells 9361401eb7 [PATCH] BLOCK: Make it possible to disable the block layer [try #6]
Make it possible to disable the block layer.  Not all embedded devices require
it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require
the block layer to be present.

This patch does the following:

 (*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev
     support.

 (*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls
     an item that uses the block layer.  This includes:

     (*) Block I/O tracing.

     (*) Disk partition code.

     (*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS.

     (*) The SCSI layer.  As far as I can tell, even SCSI chardevs use the
     	 block layer to do scheduling.  Some drivers that use SCSI facilities -
     	 such as USB storage - end up disabled indirectly from this.

     (*) Various block-based device drivers, such as IDE and the old CDROM
     	 drivers.

     (*) MTD blockdev handling and FTL.

     (*) JFFS - which uses set_bdev_super(), something it could avoid doing by
     	 taking a leaf out of JFFS2's book.

 (*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and
     linux/elevator.h contingent on CONFIG_BLOCK being set.  sector_div() is,
     however, still used in places, and so is still available.

 (*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and
     parts of linux/fs.h.

 (*) Makes a number of files in fs/ contingent on CONFIG_BLOCK.

 (*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK.

 (*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK
     is not enabled.

 (*) fs/no-block.c is created to hold out-of-line stubs and things that are
     required when CONFIG_BLOCK is not set:

     (*) Default blockdev file operations (to give error ENODEV on opening).

 (*) Makes some /proc changes:

     (*) /proc/devices does not list any blockdevs.

     (*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK.

 (*) Makes some compat ioctl handling contingent on CONFIG_BLOCK.

 (*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if
     given command other than Q_SYNC or if a special device is specified.

 (*) In init/do_mounts.c, no reference is made to the blockdev routines if
     CONFIG_BLOCK is not defined.  This does not prohibit NFS roots or JFFS2.

 (*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return
     error ENOSYS by way of cond_syscall if so).

 (*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if
     CONFIG_BLOCK is not set, since they can't then happen.

Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-09-30 20:52:31 +02:00
Martin Peschke 4090959aee [PATCH] blktrace: cleanup using on_each_cpu
This patch kills a few lines of code in blktrace by making use of
on_each_cpu().

Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-09-30 20:31:19 +02:00
Oleg Nesterov 25034d7a83 [PATCH] exit_io_context: don't disable irqs
We don't need to disable irqs to clear current->io_context, it is protected
by ->alloc_lock. Even IF it was possible to submit I/O from IRQ on behalf of
current this irq_disable() can't help: current_io_context() will re-instantiate
->io_context after irq_enable().

We don't need task_lock() or local_irq_disable() to clear ioc->task. This can't
prevent other CPUs from playing with our io_context anyway.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-09-30 20:31:18 +02:00
Jens Axboe 7457e6e2d7 [PATCH] blktrace: support for logging metadata reads
Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30 20:29:43 +02:00
Jens Axboe 374f84ac39 [PATCH] cfq-iosched: use metadata read flag
Give meta data reads preference over regular reads, as the process
often needs to get that out of the way to do the io it was actually
interested in.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30 20:29:43 +02:00
Jens Axboe 5404bc7a87 [PATCH] Allow file systems to differentiate between data and meta reads
We can use this information for making more intelligent priority
decisions, and it will also be useful for blktrace.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30 20:29:42 +02:00
Jens Axboe da20a20f3b [PATCH] ll_rw_blk: allow more flexibility for read_ahead_kb store
It can make sense to set read-ahead larger than a single request.
We should not be enforcing such policy on the user. Additionally,
using the BLKRASET ioctl doesn't impose such a restriction. So
additionally we now expose identical behaviour through the two.

Issue also reported by Anton <cbou@mail.ru>

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30 20:29:41 +02:00
Jens Axboe bf57225670 [PATCH] cfq-iosched: improve queue preemption
Don't touch the current queues, just make sure that the wanted queue
is selected next. Simplifies the logic.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30 20:29:41 +02:00
Jens Axboe dc72ef4ae3 [PATCH] Add blk_start_queueing() helper
CFQ implements this on its own now, but it's really block layer
knowledge. Tells a device queue to start dispatching requests to
the driver, taking care to unplug if needed. Also fixes the issue
where as/cfq will invoke a stopped queue, which we really don't
want.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30 20:29:40 +02:00
Jens Axboe 981a79730d [PATCH] cfq-iosched: kill the empty_list
No point in having a place holder list just for empty queues, so remove
it. It's not used for anything other than to keep ->cfq_list busy.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30 20:29:40 +02:00
Jens Axboe 53b03744e5 [PATCH] cfq-iosched: Kill O(N) runtime of cfq_resort_rr_list()
Currently it scales with number of processes in that priority group,
which is potentially not very nice as it's called quite often.
Basically we always need to do tail inserts, except for the case of a
new process. So just mark/detect a queue as such.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30 20:29:39 +02:00
Jens Axboe b5deef9012 [PATCH] Make sure all block/io scheduler setups are node aware
Some were kmalloc_node(), some were still kmalloc(). Change them all to
kmalloc_node().

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30 20:29:39 +02:00
Jens Axboe 1ea25ecb72 [PATCH] Audit block layer inlines
Kill a few inlines that bring in too much code to more than one location
Shrinks kernel text by about 300 bytes on 32-bit x86.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30 20:29:38 +02:00
Jens Axboe 4050cf1674 [PATCH] cfq-iosched: use new io context counting mechanism
It's ok if the read path is a lot more costly, as long as inc/dec is
really cheap. The inc/dec will happen for each created/freed io context,
while the reading only happens when a disk queue exits.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30 20:29:37 +02:00
Jens Axboe e4313dd423 [PATCH] as-iosched: use new io context counting mechanism
It's ok if the read path is a lot more costly, as long as inc/dec is
really cheap. The inc/dec will happen for each created/freed io context,
while the reading only happens when a disk queue exits.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30 20:29:37 +02:00
Jens Axboe fc46379daf [PATCH] cfq-iosched: kill cfq_exit_lock
cfq_exit_lock is protecting two things now:

- The per-ioc rbtree of cfq_io_contexts

- The per-cfqd linked list of cfq_io_contexts

The per-cfqd linked list can be protected by the queue lock, as it is (by
definition) per cfqd as the queue lock is.

The per-ioc rbtree is mainly used and updated by the process itself only.
The only outside use is the io priority changing. If we move the
priority changing to not browsing the rbtree, we can remove any locking
from the rbtree updates and lookup completely. Let the sys_ioprio syscall
just mark processes as having the iopriority changed and lazily update
the private cfq io contexts the next time io is queued, and we can
remove this locking as well.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30 20:29:36 +02:00
Jens Axboe 89850f7ee9 [PATCH] cfq-iosched: cleanups, fixes, dead code removal
A collection of little fixes and cleanups:

- We don't use the 'queued' sysfs exported attribute, since the
  may_queue() logic was rewritten. So kill it.

- Remove dead defines.

- cfq_set_active_queue() can be rewritten cleaner with else if conditions.

- Several places had cfq_exit_cfqq() like logic, abstract that out and
  use that.

- Annotate the cfqq kmem_cache_alloc() so the allocator knows that this
  is a repeat allocation if it fails with __GFP_WAIT set. Allows the
  allocator to start freeing some memory, if needed. CFQ already loops for
  this condition, so might as well pass the hint down.

- Remove cfqd->rq_starved logic. It's not needed anymore after we dropped
  the crq allocation in cfq_set_request().

- Remove uneeded parameter passing.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30 20:29:35 +02:00
Jens Axboe 51da90fcb6 [PATCH] ll_rw_blk: cleanup __make_request()
- Don't assign variables that are only used once.

- Kill spin_lock() prefetching, it's opportunistic at best.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30 20:29:34 +02:00
Jens Axboe cb78b285c8 [PATCH] Drop useless bio passing in may_queue/set_request API
It's not needed for anything, so kill the bio passing.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30 20:29:23 +02:00
Jens Axboe cdd6026217 [PATCH] Remove ->rq_status from struct request
After Christophs SCSI change, the only usage left is RQ_ACTIVE
and RQ_INACTIVE. The block layer sets RQ_INACTIVE right before freeing
the request, so any check for RQ_INACTIVE in a driver is a bug and
indicates use-after-free.

So kill/clean the remaining users, straight forward.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30 20:29:23 +02:00
Jens Axboe 49171e5c6f [PATCH] Remove struct request_list from struct request
It is always identical to &q->rq, and we only use it for detecting
whether this request came out of our mempool or not. So replace it
with an additional ->flags bit flag.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30 20:29:22 +02:00
Jens Axboe c00895ab2f [PATCH] Remove ->waiting member from struct request
As the comments indicates in blkdev.h, we can fold it into ->end_io_data
usage as that is really what ->waiting is. Fixup the users of
blk_end_sync_rq().

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-09-30 20:29:12 +02:00
Jens Axboe 8a8e674cb1 [PATCH] as-iosched: kill arq
Get rid of the as_rq request type. With the added elevator_private2, we
have enough room in struct request to get rid of any arq allocation/free
for each request.

Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Nick Piggin <npiggin@suse.de>
2006-09-30 20:27:02 +02:00
Jens Axboe 5e70537479 [PATCH] cfq-iosched: kill crq
Get rid of the cfq_rq request type. With the added elevator_private2, we
have enough room in struct request to get rid of any crq allocation/free
for each request.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30 20:27:02 +02:00
Jens Axboe 5380a101d3 [PATCH] cfq-iosched: remove the crq flag functions/variable
There's just one flag currently (SYNC), and that one can be grabbed from
the request.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30 20:27:01 +02:00
Jens Axboe 8840faa1ee [PATCH] deadline-iosched: remove elevator private drq request type
A big win, we now save an allocation/free on each request! With the
previous rb/hash abstractions, we can just reuse queuelist/donelist
for the FIFO data and be done with it.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30 20:27:00 +02:00
Jens Axboe 9e2585a8a2 [PATCH] as-iosched: remove arq->is_sync member
We can track this in struct request.

Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Nick Piggin <npiggin@suse.de>
2006-09-30 20:27:00 +02:00
Jens Axboe d4f2f4629e [PATCH] as-iosched: reuse rq for fifo
Saves some space in arq.

Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Nick Piggin <npiggin@suse.de>
2006-09-30 20:27:00 +02:00
Jens Axboe 95e8810b28 [PATCH] cfq-iosched: convert to using the FIFO elevator defines
Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30 20:26:59 +02:00
Jens Axboe b8aca35af5 [PATCH] deadline-iosched: migrate to using the elevator rb functions
This removes the rbtree handling from deadline.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30 20:26:58 +02:00
Jens Axboe 21183b07ee [PATCH] cfq-iosched: migrate to using the elevator rb functions
This removes the rbtree handling from CFQ.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30 20:26:58 +02:00
Jens Axboe e37f346e34 [PATCH] as-iosched: migrate to using the elevator rb functions
This removes the rbtree handling from AS.

Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Nick Piggin <npiggin@suse.de>
2006-09-30 20:26:57 +02:00
Jens Axboe 2e662b65f0 [PATCH] elevator: abstract out the rbtree sort handling
The rbtree sort/lookup/reposition logic is mostly duplicated in
cfq/deadline/as, so move it to the elevator core. The io schedulers
still provide the actual rb root, as we don't want to impose any sort
of specific handling on the schedulers.

Introduce the helpers and rb_node in struct request to help migrate the
IO schedulers.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30 20:26:57 +02:00
Jens Axboe 10fd48f237 [PATCH] rbtree: fixed reversed RB_EMPTY_NODE and rb_next/prev
The conditions got reserved. Also make rb_next() and rb_prev() check
for the empty condition.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30 20:26:56 +02:00
Jens Axboe 9817064b68 [PATCH] elevator: move the backmerging logic into the elevator core
Right now, every IO scheduler implements its own backmerging (except for
noop, which does no merging). That results in duplicated code for
essentially the same operation, which is never a good thing. This patch
moves the backmerging out of the io schedulers and into the elevator
core. We save 1.6kb of text and as a bonus get backmerging for noop as
well. Win-win!

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30 20:26:56 +02:00
Jens Axboe 4aff5e2333 [PATCH] Split struct request ->flags into two parts
Right now ->flags is a bit of a mess: some are request types, and
others are just modifiers. Clean this up by splitting it into
->cmd_type and ->cmd_flags. This allows introduction of generic
Linux block message types, useful for sending generic Linux commands
to block devices.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30 20:23:37 +02:00
Alexey Dobriyan 6c5c934153 [PATCH] ifdef blktrace debugging fields
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 09:18:09 -07:00
Randy Dunlap 87a5726110 [PATCH] block: handle subsystem_register() init errors
Check and handle init errors.

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 09:18:05 -07:00
Theodore Ts'o 8e18e2941c [PATCH] inode_diet: Replace inode.u.generic_ip with inode.i_private
The following patches reduce the size of the VFS inode structure by 28 bytes
on a UP x86.  (It would be more on an x86_64 system).  This is a 10% reduction
in the inode size on a UP kernel that is configured in a production mode
(i.e., with no spinlock or other debugging functions enabled; if you want to
save memory taken up by in-core inodes, the first thing you should do is
disable the debugging options; they are responsible for a huge amount of bloat
in the VFS inode structure).

This patch:

The filesystem or device-specific pointer in the inode is inside a union,
which is pretty pointless given that all 30+ users of this field have been
using the void pointer.  Get rid of the union and rename it to i_private, with
a comment to explain who is allowed to use the void pointer.  This is just a
cleanup, but it allows us to reuse the union 'u' for something something where
the union will actually be used.

[judith@osdl.org: powerpc build fix]
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Judith Lebzelter <judith@osdl.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-27 08:26:17 -07:00
James Bottomley 1aedf2ccc6 Merge mulgrave-w:git/linux-2.6
Conflicts:

	include/linux/blkdev.h

Trivial merge to incorporate tag prototypes.
2006-09-23 21:03:52 -05:00
Trond Myklebust 275a082fe9 Add a real API for dealing with blk_congestion_wait()
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-09-22 23:24:54 -04:00
James Bottomley 492dfb4896 [SCSI] block: add support for shared tag maps
The current block queue implementation already contains most of the
machinery for shared tag maps.  The only remaining pieces are a way to
allocate and destroy a tag map independently of the queues (so that
the maps can be managed on the life cycle of the overseeing entity)

Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-08-31 11:17:18 -04:00
Oleg Nesterov 2d8f613160 elv_unregister: fix possible crash on module unload
An exiting task or process which didn't do I/O yet have no io context,
elv_unregister() should check it is not NULL.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-08-22 12:52:23 -07:00
Oleg Nesterov be33c3a67b [PATCH] cfq_cic_link: fix usage of wrong cfq_io_context
Obviously, cfq_cic_link() shouldn't free a just allocated cfq_io_context?
The dead key is from __cic, so drop that.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Jens Axboe <axboe@suse.de>
2006-08-21 10:02:54 +02:00
Oleg Nesterov 9f83e45eb5 [PATCH] Fix current_io_context() vs set_task_ioprio() race
I know nothing about io scheduler, but I suspect set_task_ioprio() is not safe.

current_io_context() initializes "struct io_context", then sets ->io_context.
set_task_ioprio() running on another cpu may see the changes out of order, so
->set_ioprio(ioc) may use io_context which was not initialized properly.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Jens Axboe <axboe@suse.de>
2006-08-21 08:34:15 +02:00
Jens Axboe 44eb123126 [PATCH] cfq-iosched: don't use a hard jiffies value, translate from msecs
The CIC_SEEKY() test really wants to use the minimum of either:

- 2 msecs (not jiffies)

- or, the pending slice time

So code it like that.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-07-25 15:05:21 +02:00
Milton Miller ad01b1ca79 [PATCH] blktrace: fix read-ahead bit
It should be toggling the same bit on and off, fix it up.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-07-25 15:04:13 +02:00
Arjan van de Ven ddca60c590 [PATCH] lockdep: annotate the BLKPG_DEL_PARTITION ioctl
The delete partition IOCTL takes the bd_mutex for both the disk and the
partition; these have an obvious hierarchical relationship and this patch
annotates this relationship for lockdep.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-14 21:53:53 -07:00
Jens Axboe 1959d21232 [PATCH] Only the first two bits in bio->bi_rw and rq->flags match
Not three, as assumed. This causes the barrier bit to be needlessly set
for some IO.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-07-06 10:18:05 +02:00
Nathan Scott 40359ccb83 [PATCH] blktrace: readahead support
Provide the needed kernel support for distinguishing readahead
from regular read requests when tracing block devices.

Signed-off-by: Nathan Scott <nathans@sgi.com>
Signed-off-by: Jens Axboe <axboe@suse.de>
2006-07-06 10:03:28 +02:00
Ingo Molnar 60be6b9a41 [PATCH] lockdep: annotate on-stack completions
lockdep needs to have the waitqueue lock initialized for on-stack waitqueues
implicitly initialized by DECLARE_COMPLETION().  Annotate on-stack completions
accordingly.

Has no effect on non-lockdep kernels.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 15:27:09 -07:00
Linus Torvalds 22a3e233ca Merge git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial
* git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial:
  Remove obsolete #include <linux/config.h>
  remove obsolete swsusp_encrypt
  arch/arm26/Kconfig typos
  Documentation/IPMI typos
  Kconfig: Typos in net/sched/Kconfig
  v9fs: do not include linux/version.h
  Documentation/DocBook/mtdnand.tmpl: typo fixes
  typo fixes: specfic -> specific
  typo fixes in Documentation/networking/pktgen.txt
  typo fixes: occuring -> occurring
  typo fixes: infomation -> information
  typo fixes: disadvantadge -> disadvantage
  typo fixes: aquire -> acquire
  typo fixes: mecanism -> mechanism
  typo fixes: bandwith -> bandwidth
  fix a typo in the RTC_CLASS help text
  smb is no longer maintained

Manually merged trivial conflict in arch/um/kernel/vmlinux.lds.S
2006-06-30 15:39:30 -07:00
Christoph Lameter f8891e5e1f [PATCH] Light weight event counters
The remaining counters in page_state after the zoned VM counter patches
have been applied are all just for show in /proc/vmstat.  They have no
essential function for the VM.

We use a simple increment of per cpu variables.  In order to avoid the most
severe races we disable preempt.  Preempt does not prevent the race between
an increment and an interrupt handler incrementing the same statistics
counter.  However, that race is exceedingly rare, we may only loose one
increment or so and there is no requirement (at least not in kernel) that
the vm event counters have to be accurate.

In the non preempt case this results in a simple increment for each
counter.  For many architectures this will be reduced by the compiler to a
single instruction.  This single instruction is atomic for i386 and x86_64.
 And therefore even the rare race condition in an interrupt is avoided for
both architectures in most cases.

The patchset also adds an off switch for embedded systems that allows a
building of linux kernels without these counters.

The implementation of these counters is through inline code that hopefully
results in only a single instruction increment instruction being emitted
(i386, x86_64) or in the increment being hidden though instruction
concurrency (EPIC architectures such as ia64 can get that done).

Benefits:
- VM event counter operations usually reduce to a single inline instruction
  on i386 and x86_64.
- No interrupt disable, only preempt disable for the preempt case.
  Preempt disable can also be avoided by moving the counter into a spinlock.
- Handling is similar to zoned VM counters.
- Simple and easily extendable.
- Can be omitted to reduce memory use for embedded use.

References:

RFC http://marc.theaimsgroup.com/?l=linux-kernel&m=113512330605497&w=2
RFC http://marc.theaimsgroup.com/?l=linux-kernel&m=114988082814934&w=2
local_t http://marc.theaimsgroup.com/?l=linux-kernel&m=114991748606690&w=2
V2 http://marc.theaimsgroup.com/?t=115014808400007&r=1&w=2
V3 http://marc.theaimsgroup.com/?l=linux-kernel&m=115024767022346&w=2
V4 http://marc.theaimsgroup.com/?l=linux-kernel&m=115047968808926&w=2

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-30 11:25:36 -07:00
Jörn Engel 6ab3d5624e Remove obsolete #include <linux/config.h>
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-30 19:25:36 +02:00
Chandra Seetharaman 5a67e4c5b6 [PATCH] cpu hotplug: use hotplug version of cpu notifier in appropriate places
Make use the of newly defined hotplug version of cpu_notifier functionality
wherever appropriate.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:41 -07:00
Chandra Seetharaman 054cc8a2d8 [PATCH] cpu hotplug: revert initdata patch submitted for 2.6.17
This patch reverts notifier_block changes made in 2.6.17

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:41 -07:00
Andreas Mohr d6e05edc59 spelling fixes
acquired (aquired)
contiguous (contigious)
successful (succesful, succesfull)
surprise (suprise)
whether (weather)
some other misspellings

Signed-off-by: Andreas Mohr <andi@lisas.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-26 18:35:02 +02:00
Andi Kleen 8269730b38 [BLOCK] Fix bounce limit address check
Do a safer check for when to enable DMA. Currently we enable ISA DMA
for cases that do not need it, resulting in OOM conditions when ZONE_DMA
runs out of space.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-06-23 17:10:39 +02:00
Jens Axboe dd67d05152 [PATCH] rbtree: support functions used by the io schedulers
They all duplicate macros to check for empty root and/or node, and
clearing a node. So put those in rbtree.h.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-06-23 17:10:39 +02:00
Jens Axboe fd61af0384 [PATCH] cfq-iosched: rq update fixes
- Remember to set ->last_sector so that the cfq_choose_req() logic
  works correctly.

- Remove redundant call to cfq_choose_req()

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-06-23 17:10:39 +02:00
Jens Axboe caaa5f9f0a [PATCH] cfq-iosched: many performance fixes
This is a collection of patches that greatly improve CFQ performance
in some circumstances.

- Change the idling logic to only kick in after a request is done and we
  are deciding what to do. Before the idling included the request service
  time, so it was hard to adjust. Now it's true think/idle time.

- Take advantage of TCQ/NCQ/queueing for seeky sync workloads, but keep
  it in control for sync and sequential (or close to) workloads.

- Expire queues immediately and move on to other busy queues, if we are
  not going to idle after the current one finishes.

- Don't rearm idle timer if there are no busy queues. Just leave the
  system idle.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-06-23 17:10:39 +02:00
Jens Axboe 35e6077cb1 [PATCH] cfq-iosched: correctly set ioprio on both targets
Patch originally from Vasily Tarasov <vtaras@sw.ru>

If you set io-priority of process 1 using sys_ioprio_set system call by
another process 2 (like ionice do), then cfq_init_prio_data() function
sets priority of process 2 (current) on queue of process 1 and clears
the flag, that designates change of ioprio.  So the process  1 will work
like with priority of process 2.

I propose not to call cfq_init_prio_data() on io-priority change, but
only mark queue as queue with changed prority.  Every time when new
request comes cfq-scheduler checks for this flag and atomaticaly changes
priority of queue to new value.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-06-23 17:10:39 +02:00
Jens Axboe b17fd9bceb [PATCH] Make CFQ the default IO scheduler
Signed-off-by: Jens Axboe <axboe@suse.de>
2006-06-23 17:10:39 +02:00
Jens Axboe b31dc66a54 [PATCH] Kill PF_SYNCWRITE flag
A process flag to indicate whether we are doing sync io is incredibly
ugly. It also causes performance problems when one does a lot of async
io and then proceeds to sync it. Part of the io will go out as async,
and the other part as sync. This causes a disconnect between the
previously submitted io and the synced io. For io schedulers such as CFQ,
this will cause us lost merges and suboptimal behaviour in scheduling.

Remove PF_SYNCWRITE completely from the fsync/msync paths, and let
the O_DIRECT path just directly indicate that the writes are sync
by using WRITE_SYNC instead.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-06-23 17:10:39 +02:00
Jens Axboe 271f18f102 [PATCH] cfq-iosched: Don't set the queue batching limits
We cannot update them if the user changes nr_requests, so don't
set it in the first place. The gains are pretty questionable as
well. The batching loss has been shown to decrease throughput.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-06-23 17:10:38 +02:00
Dave Jones acf4217555 [PATCH] remove dead code from elevator switching
We already drop the refcount in elevator_exit(), and as
we're setting 'e' to NULL, we'll never take that branch anyway.
Finally, as 'e' is a local var that isn't referenced afterwards,
setting it to NULL is pointless.

Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Jens Axboe <axboe@suse.de>
2006-06-23 17:10:38 +02:00
Paolo 'Blaisorblade' Giarrusso a038e25364 [PATCH] blk_start_queue() must be called with irq disabled - add warning
The queue lock can be taken from interrupts so it must always be taken with
irq disabling primitives.  Some primitives already verify this.
blk_start_queue() is called under this lock, so interrupts must be
disabled.

Also document this requirement clearly in blk_init_queue(), where the queue
spinlock is set.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Jens Axboe <axboe@suse.de>
2006-06-23 17:10:38 +02:00
Akinobu Mita bae386f788 [PATCH] iosched: use hlist for request hashtable
Use hlist instead of list_head for request hashtable in deadline-iosched
and as-iosched. It also can remove the flag to know hashed or unhashed.

Signed-off-by: Akinobu Mita <mita@miraclelinux.com>
Signed-off-by: Jens Axboe <axboe@suse.de>

 block/as-iosched.c       |   45 +++++++++++++++++++--------------------------
 block/deadline-iosched.c |   39 ++++++++++++++++-----------------------
 2 files changed, 35 insertions(+), 49 deletions(-)
2006-06-23 17:10:38 +02:00
Oleg Nesterov 626ab0e69d [PATCH] list: use list_replace_init() instead of list_splice_init()
list_splice_init(list, head) does unneeded job if it is known that
list_empty(head) == 1.  We can use list_replace_init() instead.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 07:43:07 -07:00
Kay Sievers b9d9c82b4d [PATCH] Driver core: add generic "subsystem" link to all devices
Like the SUBSYTEM= key we find in the environment of the uevent, this
creates a generic "subsystem" link in sysfs for every device. Userspace
usually doesn't care at all if its a "class" or a "bus" device. This
provides an unified way to determine the subsytem of a device, regardless
of the way the driver core has created it.

Signed-off-by: Kay Sievers <kay.sievers@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-21 12:40:49 -07:00
Linus Torvalds 6b41fd1785 Fix up CFQ scheduler for recent rbtree node shrinkage
The color is now in the low bits of the parent pointer, and initializing
it to 0 happens as part of the whole memset above, so just remove the
unnecessary RB_CLEAR_COLOR.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-20 19:44:03 -07:00
Linus Torvalds 2edc322d42 Merge git://git.infradead.org/~dwmw2/rbtree-2.6
* git://git.infradead.org/~dwmw2/rbtree-2.6:
  [RBTREE] Switch rb_colour() et al to en_US spelling of 'color' for consistency
  Update UML kernel/physmem.c to use rb_parent() accessor macro
  [RBTREE] Update hrtimers to use rb_parent() accessor macro.
  [RBTREE] Add explicit alignment to sizeof(long) for struct rb_node.
  [RBTREE] Merge colour and parent fields of struct rb_node.
  [RBTREE] Remove dead code in rb_erase()
  [RBTREE] Update JFFS2 to use rb_parent() accessor macro.
  [RBTREE] Update eventpoll.c to use rb_parent() accessor macro.
  [RBTREE] Update key.c to use rb_parent() accessor macro.
  [RBTREE] Update ext3 to use rb_parent() accessor macro.
  [RBTREE] Change rbtree off-tree marking in I/O schedulers.
  [RBTREE] Add accessor macros for colour and parent fields of rb_node
2006-06-20 14:51:22 -07:00
Jens Axboe 553698f944 [PATCH] cfq-iosched: fix crash in do_div()
We don't clear the seek stat values in cfq_alloc_io_context(), and if
->seek_mean is unlucky enough to be set to -36 by chance, the first
invocation of cfq_update_io_seektime() will oops with a divide by zero
in do_div().

Just memset the entire cic instead of filling invididual values
independently.

Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-14 10:22:16 -07:00
Jens Axboe bc1c116974 [PATCH] elevator switching race
There's a race between shutting down one io scheduler and firing up the
next, in which a new io could enter and cause the io scheduler to be
invoked with bad or NULL data.

To fix this, we need to maintain the queue lock for a bit longer.
Unfortunately we cannot do that, since the elevator init requires to be
run without the lock held.  This isn't easily fixable, without also
changing the mempool API.  So split the initialization into two parts,
and alloc-init operation and an attach operation.  Then we can
preallocate the io scheduler and related structures, and run the attach
inside the lock after we detach the old one.

This patch has survived 30 minutes of 1 second io scheduler switching
with a very busy io load.

Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-08 15:14:23 -07:00
Jens Axboe b52a834892 [PATCH] cfq-iosched: busy_rr fairness fix
Now that we select busy_rr for possible service, insert entries at the
back of that list instead of at the front.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-06-01 18:53:43 +02:00
Jens Axboe ae818a38d4 [PATCH] cfq-iosched: fix bug in timer handling for the idle class
There's a small window from when the timer is entered and we grab
the queue lock, where cfq_set_active_queue() could be rearming the
timer for us. Seen in the wild on a 12-way ppc box. Fix this by
just using mod_timer(), which will do the right thing for us.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-06-01 10:13:43 +02:00
Jens Axboe 25776e3594 [PATCH] cfq-iosched: Detect hardware queueing
If the hardware is doing real queueing, decide that it's worthless to
idle the hardware. It does reasonable simultaneous io in that case
anyways, and the idling hurts some work loads.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-06-01 10:12:26 +02:00