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path: root/block/blk-sysfs.c
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2009-04-24block: simplify I/O stat accountingJerome Marchand
This simplifies I/O stat accounting switching code and separates it completely from I/O scheduler switch code. Requests are accounted according to the state of their request queue at the time of the request allocation. There is no need anymore to flush the request queue when switching I/O accounting state. Signed-off-by: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15block: fix bad spelling of quiesceJens Axboe
Credit goes to Andrew Morton for spotting this one. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-07block: fix inconsistency in I/O stat accounting codeJerome Marchand
This forces in_flight to be zero when turning off or on the I/O stat accounting and stops updating I/O stats in attempt_merge() when accounting is turned off. Signed-off-by: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-06block: change the request allocation/congestion logic to be sync/async basedJens Axboe
This makes sure that we never wait on async IO for sync requests, instead of doing the split on writes vs reads. Signed-off-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-30block: add sysfs file for controlling io stats accountingJens Axboe
This allows us to turn off disk stat accounting completely, for the cases where the 0.5-1% reduction in system time is important. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-01-30block: export SSD/non-rotational queue flag through sysfsBartlomiej Zolnierkiewicz
For some devices (i.e. CFA ATA) we can't reliably detect whether the device is of rotational or non-rotational type so we need to leave the final decision about this setting to the user-space. As a bonus do a minor CodingStyle fixup in queue_nomerges_store(). Suggested-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29block: don't take lock on changing ra_pagesWu Fengguang
There's no need to take queue_lock or kernel_lock when modifying bdi->ra_pages. So remove them. Also remove out of date comment for queue_max_sectors_store(). Signed-off-by: Wu Fengguang <wfg@linux.intel.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-10-09block: add support for IO CPU affinityJens Axboe
This patch adds support for controlling the IO completion CPU of either all requests on a queue, or on a per-request basis. We export a sysfs variable (rq_affinity) which, if set, migrates completions of requests to the CPU that originally submitted it. A bio helper (bio_set_completion_cpu()) is also added, so that queuers can ask for completion on that specific CPU. In testing, this has been show to cut the system time by as much as 20-40% on synthetic workloads where CPU affinity is desired. This requires a little help from the architecture, so it'll only work as designed for archs that are using the new generic smp helper infrastructure. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-10-09block: implement and use {disk|part}_to_dev()Tejun Heo
Implement {disk|part}_to_dev() and use them to access generic device instead of directly dereferencing {disk|part}->dev. To make sure no user is left behind, rename generic devices fields to __dev. This is in preparation of unifying partition 0 handling with other partitions. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-05-07block: sysfs store function needs to grab queue_lock and use queue_flag_*()Jens Axboe
Concurrency isn't a big deal here since we have requests in flight at this point, but do the locked variant to set a better example. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-04-29block: Skip I/O merges when disabledAlan D. Brunelle
The block I/O + elevator + I/O scheduler code spend a lot of time trying to merge I/Os -- rightfully so under "normal" circumstances. However, if one were to know that the incoming I/O stream was /very/ random in nature, the cycles are wasted. This patch adds a per-request_queue tunable that (when set) disables merge attempts (beyond the simple one-hit cache check), thus freeing up a non-trivial amount of CPU cycles. Signed-off-by: Alan D. Brunelle <alan.brunelle@hp.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-04-21block: fix blk_register_queue() return valueAkinobu Mita
blk_register_queue() returns -ENXIO when queue->request_fn is NULL. But there are some block drivers that call blk_register_queue() via add_disk() with queue->request_fn == NULL. (For example, brd, loop) Although no one checks return value of blk_register_queue(), this patch makes it return 0 instead of -ENXIO when queue->request_fn is NULL, Also this patch adds warning when blk_register_queue() and blk_unregister_queue() are called with queue == NULL rather than ignore invalid usage silently. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-02-01block: make core bits checkpatch compliantJens Axboe
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-01-29Expose hardware sector sizeMartin K. Petersen
Expose hardware sector size in sysfs queue directory. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-01-29block: split tag and sysfs handling from blk-core.cJens Axboe
Seperates the tag and sysfs handling from ll_rw_blk. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>