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path: root/drivers/block/cfq-iosched.c
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* [PATCH] cfq-iosched.c: minor fixesJens Axboe2005-08-24
| | | | | | | | | | | | | One critical fix and two minor fixes for 2.6.13-rc7: - Max depth must currently be 2 to allow barriers to function on SCSI - Prefer sync request over async in choosing the next request - Never allow async request to preempt or disturb the "anticipation" for a single cfq process context. This is as-designed, the code right now is buggy in that area. Signed-off-by: Jens Axboe <axboe@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] cfq-iosched: fix problem with barriers and max_depth == 1Jens Axboe2005-08-02
| | | | | | | | | | | | CFQ will currently stall when using write barriers and the default max_depth setting of 1, since we artificially need a depth of 2 when pre-pending the first flush. So never deny the barrier request going to the device. This is a regression since 2.6.12, it was found in SUSE testing. Signed-off-by: Jens Axboe <axboe@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] cfq build fixAndrew Morton2005-06-27
| | | | | | | | | | | | | | | drivers/block/cfq-iosched.c: In function 'cfq_put_queue': drivers/block/cfq-iosched.c:303: sorry, unimplemented: inlining failed in call to 'cfq_pending_requests': function body not available drivers/block/cfq-iosched.c:1080: sorry, unimplemented: called from here drivers/block/cfq-iosched.c: In function '__cfq_may_queue': drivers/block/cfq-iosched.c:1955: warning: the address of 'cfq_cfqq_must_alloc_slice', will always evaluate as 'true' make[1]: *** [drivers/block/cfq-iosched.o] Error 1 make: *** [drivers/block/cfq-iosched.o] Error 2 Cc: Jeff Garzik <jgarzik@pobox.com> Cc: Jens Axboe <axboe@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] CFQ io scheduler: scheduler switch oopsJens Axboe2005-06-27
| | | | | | | | | | | If cfq is managing a queue and a new scheduler is later selected, it is possible for the cfqd unplug_work work to be queued after the kblockd work struct has been flushed. The problem is the ordering of cfq_shutdown_timer_wq() and blk_put_queue() in cfq_put_cfqd(). The latter may rearm the work, leaving cfq_kick_queue() with dead data. Signed-off-by: Jens Axboe <axboe@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] CFQ io scheduler updatesJens Axboe2005-06-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Adjust slice values - Instead of one async queue, one is defined per priority level. This prevents kernel threads (such as reiserfs/x and others) that run at higher io priority from conflicting with others. Previously, it was a coin toss what io prio the async queue got, it was defined by who first set up the queue. - Let a time slice only begin, when the previous slice is completely done. Previously we could be somewhat unfair to a new sync slice, if the previous slice was async and had several ios queued. This might need a little tweaking if throughput suffers a little due to this, allowing perhaps an overlap of a single request or so. - Optimize the calling of kblockd_schedule_work() by doing it only when it is strictly necessary (no requests in driver and work left to do). - Correct sync vs async logic. A 'normal' process can be purely async as well, and a flusher can be purely sync as well. Sync or async is now a property of the class defined and requests pending. Previously writers could be considered sync, when they were really async. - Get rid of the bit fields in cfqq and crq, use flags instead. - Various other cleanups and fixes Signed-off-by: Jens Axboe <axboe@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Fix cfq_find_next_crq()Jens Axboe2005-06-27
| | | | | | | | | | | | | | | | In cfq_find_next_crq(), cfq tries to find the next request by choosing one of two requests before and after the current one. Currently, when choosing the next request, if there's no next request, the next candidate is NULL, resulting in selection of the previous request. This results in weird scheduling. Once we reach the end, we always seek backward. The correct behavior is using the first request as the next candidate. cfq_choose_req() already has logics for handling wrapped requests. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jens Axboe <axboe@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Update cfq io scheduler to time sliced designJens Axboe2005-06-27
| | | | | | | | | | | | | | This updates the CFQ io scheduler to the new time sliced design (cfq v3). It provides full process fairness, while giving excellent aggregate system throughput even for many competing processes. It supports io priorities, either inherited from the cpu nice value or set directly with the ioprio_get/set syscalls. The latter closely mimic set/getpriority. This import is based on my latest from -mm. Signed-off-by: Jens Axboe <axboe@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sysfs: (driver/block) if show/store is missing return -EIODmitry Torokhov2005-06-20
| | | | | | | | | sysfs: fix drivers/block so if an attribute doesn't implement show or store method read/write will return -EIO instead of 0 or -EINVAL. Signed-off-by: Dmitry Torokhov <dtor@mail.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* When cfq I/O scheduler is selected, get_request() in __make_request() callsKiyoshi Ueda2005-06-17
| | | | | | | | | | | | | | | | | | | | | __cfq_get_queue(). __cfq_get_queue() finds an existing queue (struct cfq_queue) of the current process for the device and returns it. If it's not found, __cfq_get_queue() creates and returns a new one if __cfq_get_queue() is called with __GFP_WAIT flag, or __cfq_get_queue() returns NULL (this means that get_request() fails) if no __GFP_WAIT flag. On the other hand, in __make_request(), get_request() is called without __GFP_WAIT flag at the first time. Thus, the get_request() fails when there is no existing queue, typically when it's called for the first I/O request of the process to the device. Though it will be followed by get_request_wait() for general case, __make_request() will just end the I/O with an error (EWOULDBLOCK) when the request was for read-ahead. Signed-off-by: Jens Axboe <axboe@suse.de> Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
* Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds2005-04-16
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!