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path: root/block/as-iosched.c
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2006-06-08[PATCH] elevator switching raceJens Axboe
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>
2006-04-18[PATCH 1/2] iosched: fix typo and barrier()OGAWA Hirofumi
On rmmod path, cfq/as waits to make sure all io-contexts was freed. However, it's using complete(), not wait_for_completion(). I think barrier() is not enough in here. To avoid the following case, this patch replaces barrier() with smb_wmb(). cpu0 visibility cpu1 [ioc_gnone=NULL,ioc_count=1] ioc_gnone = &all_gone NULL,ioc_count=1 atomic_read(&ioc_count) NULL,ioc_count=1 wait_for_completion() NULL,ioc_count=0 atomic_sub_and_test() NULL,ioc_count=0 if ( && ioc_gone) [ioc_gone==NULL, so doesn't call complete()] &all_gone,ioc_count=0 Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Jens Axboe <axboe@suse.de>
2006-03-18[PATCH] fix rmmod problems with elevator attributes, clean them upAl Viro
2006-03-18[PATCH] elevator_t lifetime rules and sysfs fixesAl Viro
2006-03-18[PATCH] deal with rmmod/put_io_context() racesAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-03-18[PATCH] stop elv_unregister() from rogering other iosched's data, fix lockingAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-01-06[BLOCK] as-iosched: update alias handlingTejun Heo
Unlike other ioscheds, as-iosched handles alias by chaing them using rq->queuelist. As aliased requests are very rare in the first place, this complicates merge/dispatch handling without meaningful performance improvement. This patch updates as-iosched to dump aliased requests into dispatch queue as other ioscheds do. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jens Axboe <axboe@suse.de>
2005-11-21[PATCH] as-iosched: remove state assertion in as_add_request()Jens Axboe
Kill the arq->state poison statement in as_add_request(), it can trigger for perfectly valid code that just reuses a request after io completion instead of freeing it and allocating a new one. We probably should introduce a blk_init_request() to start from scratch, but for now just kill it as we will be removing the as specific poisoning soon. Signed-off-by: Jens Axboe <axboe@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-18[BLOCK] new block/ directory comment tidyCoywolf Qi Hunt
Some leftover comments referring to drivers/block that are now block/. They don't add any information we don't already have, so kill them. Signed-off-by: Coywolf Qi Hunt <qiyong@fc-cn.com> Signed-off-by: Jens Axboe <axboe@suse.de>
2005-11-07Merge branch 'block-dir' of git://brick.kernel.dk/data/git/linux-2.6-blockLinus Torvalds
2005-11-04[BLOCK] Move all core block layer code to new block/ directoryJens Axboe
drivers/block/ is right now a mix of core and driver parts. Lets move the core parts to a new top level directory. Al will move the fs/ related block parts to block/ next. Signed-off-by: Jens Axboe <axboe@suse.de>