~ramaling/linux - Ram's kernel repositories

Age	Commit message (Collapse)	Author	Files	Lines
2014-03-03	rt,blk,mq: Make blk_mq_cpu_notify_lock a raw spinlock	Mike Galbraith	1	-7/+7
	[ 365.164040] BUG: sleeping function called from invalid context at kernel/rtmutex.c:674 [ 365.164041] in_atomic(): 1, irqs_disabled(): 1, pid: 26, name: migration/1 [ 365.164043] no locks held by migration/1/26. [ 365.164044] irq event stamp: 6648 [ 365.164056] hardirqs last enabled at (6647): [<ffffffff8153d377>] restore_args+0x0/0x30 [ 365.164062] hardirqs last disabled at (6648): [<ffffffff810ed98d>] multi_cpu_stop+0x9d/0x120 [ 365.164070] softirqs last enabled at (0): [<ffffffff810543bc>] copy_process.part.28+0x6fc/0x1920 [ 365.164072] softirqs last disabled at (0): [< (null)>] (null) [ 365.164076] CPU: 1 PID: 26 Comm: migration/1 Tainted: GF N 3.12.12-rt19-0.gcb6c4a2-rt #3 [ 365.164078] Hardware name: QCI QSSC-S4R/QSSC-S4R, BIOS QSSC-S4R.QCI.01.00.S013.032920111005 03/29/2011 [ 365.164091] 0000000000000001 ffff880a42ea7c30 ffffffff815367e6 ffffffff81a086c0 [ 365.164099] ffff880a42ea7c40 ffffffff8108919c ffff880a42ea7c60 ffffffff8153c24f [ 365.164107] ffff880a42ea91f0 00000000ffffffe1 ffff880a42ea7c88 ffffffff81297ec0 [ 365.164108] Call Trace: [ 365.164119] [<ffffffff810060b1>] try_stack_unwind+0x191/0x1a0 [ 365.164127] [<ffffffff81004872>] dump_trace+0x92/0x360 [ 365.164133] [<ffffffff81006108>] show_trace_log_lvl+0x48/0x60 [ 365.164138] [<ffffffff81004c18>] show_stack_log_lvl+0xd8/0x1d0 [ 365.164143] [<ffffffff81006160>] show_stack+0x20/0x50 [ 365.164153] [<ffffffff815367e6>] dump_stack+0x54/0x9a [ 365.164163] [<ffffffff8108919c>] __might_sleep+0xfc/0x140 [ 365.164173] [<ffffffff8153c24f>] rt_spin_lock+0x1f/0x70 [ 365.164182] [<ffffffff81297ec0>] blk_mq_main_cpu_notify+0x20/0x70 [ 365.164191] [<ffffffff81540a1c>] notifier_call_chain+0x4c/0x70 [ 365.164201] [<ffffffff81083499>] __raw_notifier_call_chain+0x9/0x10 [ 365.164207] [<ffffffff810567be>] cpu_notify+0x1e/0x40 [ 365.164217] [<ffffffff81525da2>] take_cpu_down+0x22/0x40 [ 365.164223] [<ffffffff810ed9c6>] multi_cpu_stop+0xd6/0x120 [ 365.164229] [<ffffffff810edd97>] cpu_stopper_thread+0xd7/0x1e0 [ 365.164235] [<ffffffff810863a3>] smpboot_thread_fn+0x203/0x380 [ 365.164241] [<ffffffff8107cbf8>] kthread+0xc8/0xd0 [ 365.164250] [<ffffffff8154440c>] ret_from_fork+0x7c/0xb0 [ 365.164429] smpboot: CPU 1 is now offline Signed-off-by: Mike Galbraith <bitbucket@online.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-01-28	block/blk-mq-cpu.c: use hotcpu_notifier()	Andrew Morton	1	-5/+1
	Cleaner, reduces text size when cpu hotplug is disabled. Cc: Christoph Hellwig <hch@lst.de> Cc: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2014-01-08	blk-mq: use __smp_call_function_single directly	Christoph Hellwig	1	-31/+0
	__smp_call_function_single already avoids multiple IPIs by internally queing up the items, and now also is available for non-SMP builds as a trivially correct stub, so there is no need to wrap it. If the additional lock roundtrip cause problems my patch to convert the generic IPI code to llists is waiting to get merged will fix it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-11-14	blk-mq: remove newly added instances of __cpuinit	Paul Gortmaker	1	-4/+4
	The new blk-mq code added new instances of __cpuinit usage. We removed this a couple versions ago; we now want to remove the compat no-op stubs. Introducing new users is not what we want to see at this point in time, as it will break once the stubs are gone. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-10-25	blk-mq: new multi-queue block IO queueing mechanism	Jens Axboe	1	-0/+93
	Linux currently has two models for block devices: - The classic request_fn based approach, where drivers use struct request units for IO. The block layer provides various helper functionalities to let drivers share code, things like tag management, timeout handling, queueing, etc. - The "stacked" approach, where a driver squeezes in between the block layer and IO submitter. Since this bypasses the IO stack, driver generally have to manage everything themselves. With drivers being written for new high IOPS devices, the classic request_fn based driver doesn't work well enough. The design dates back to when both SMP and high IOPS was rare. It has problems with scaling to bigger machines, and runs into scaling issues even on smaller machines when you have IOPS in the hundreds of thousands per device. The stacked approach is then most often selected as the model for the driver. But this means that everybody has to re-invent everything, and along with that we get all the problems again that the shared approach solved. This commit introduces blk-mq, block multi queue support. The design is centered around per-cpu queues for queueing IO, which then funnel down into x number of hardware submission queues. We might have a 1:1 mapping between the two, or it might be an N:M mapping. That all depends on what the hardware supports. blk-mq provides various helper functions, which include: - Scalable support for request tagging. Most devices need to be able to uniquely identify a request both in the driver and to the hardware. The tagging uses per-cpu caches for freed tags, to enable cache hot reuse. - Timeout handling without tracking request on a per-device basis. Basically the driver should be able to get a notification, if a request happens to fail. - Optional support for non 1:1 mappings between issue and submission queues. blk-mq can redirect IO completions to the desired location. - Support for per-request payloads. Drivers almost always need to associate a request structure with some driver private command structure. Drivers can tell blk-mq this at init time, and then any request handed to the driver will have the required size of memory associated with it. - Support for merging of IO, and plugging. The stacked model gets neither of these. Even for high IOPS devices, merging sequential IO reduces per-command overhead and thus increases bandwidth. For now, this is provided as a potential 3rd queueing model, with the hope being that, as it matures, it can replace both the classic and stacked model. That would get us back to having just 1 real model for block devices, leaving the stacked approach to dm/md devices (as it was originally intended). Contributions in this patch from the following people: Shaohua Li <shli@fusionio.com> Alexander Gordeev <agordeev@redhat.com> Christoph Hellwig <hch@infradead.org> Mike Christie <michaelc@cs.wisc.edu> Matias Bjorling <m@bjorling.me> Jeff Moyer <jmoyer@redhat.com> Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>