- 08 Dec, 2018 27 commits
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Chaitanya Kulkarni authored
This patch optimizes read command behavior when file-ns configured with buffered I/O. Instead of offloading the buffered I/O read operations to the worker threads, we first issue the read operation with IOCB_NOWAIT and try and access the data from the cache. Here we only offload the request to the worker thread and complete the request in the worker thread context when IOCB_NOWAIT request fails. Signed-off-by:
Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
Jens Axboe <axboe@kernel.dk>
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Sagi Grimberg authored
A controller that supports traffic based keep-alive can restart the keep alive timer even when no keep-alive was not received in the kato period as long as other admin or I/O commands were received. For each command set ctrl->cmd_seen to true, and when keep-alive timer expires, if any commands were seen, resched ka_work instead of escalating to a fatal error. Signed-off-by:
Sagi Grimberg <sagi@grimberg.me> Signed-off-by:
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Sagi Grimberg authored
If the controller supports traffic based keep alive, we restart the keep alive timer if any admin or io commands was completed during the kato period. This prevents a possible starvation of keep alive commands in the presence of heavy traffic as in such case, we already have a health indication from the host perspective. Only set a comp_seen indicator in case the controller supports keep alive to minimize the overhead for pci controllers. Signed-off-by:
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Sagi Grimberg authored
We get the controller attributes in identify, cache them as we'll need them for traffic based keep alive support. Reviewed-by:
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Sagi Grimberg authored
We are growing more controller attributes, so use a proper enumeration for it. For now just add the 128-bit hostid which we support. Reviewed-by:
Hannes Reinecke <hare@suse.com> Signed-off-by:
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Hannes Reinecke authored
Instead of directly poking into the struct device add a new numa_node field to struct nvme_ctrl. This allows fabrics drivers where ctrl->dev is a virtual device to support NUMA affinity as well. Also expose the field as a sysfs attribute, and populate it for the RDMA and FC transports. Signed-off-by:
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Chaitanya Kulkarni authored
In function nvme_setup_cmd() we call command specific setup function for flush, rw, and discard. Instead of calling memset in each function lets call it once in the parent function. This is purely code cleanup patch and it does not change any existing functionality. Signed-off-by:
Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by:
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Ming Lei authored
Now almost all .map_queues() implementation based on managed irq affinity doesn't update queue mapping and it just retrieves the old built mapping, so if nr_hw_queues is changed, the mapping talbe includes stale mapping. And only blk_mq_map_queues() may rebuild the mapping talbe. One case is that we limit .nr_hw_queues as 1 in case of kdump kernel. However, drivers often builds queue mapping before allocating tagset via pci_alloc_irq_vectors_affinity(), but set->nr_hw_queues can be set as 1 in case of kdump kernel, so wrong queue mapping is used, and kernel panic[1] is observed during booting. This patch fixes the kernel panic triggerd on nvme by rebulding the mapping table via blk_mq_map_queues(). [1] kernel panic log [ 4.438371] nvme nvme0: 16/0/0 default/read/poll queues [ 4.443277] BUG: unable to handle kernel NULL pointer dereference at 0000000000000098 [ 4.444681] PGD 0 P4D 0 [ 4.445367] Oops: 0000 [#1] SMP NOPTI [ 4.446342] CPU: 3 PID: 201 Comm: kworker/u33:10 Not tainted 4.20.0-rc5-00664-g5eb02f7ee1eb-dirty #459 [ 4.447630] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.10.2-2.fc27 04/01/2014 [ 4.448689] Workqueue: nvme-wq nvme_scan_work [nvme_core] [ 4.449368] RIP: 0010:blk_mq_map_swqueue+0xfb/0x222 [ 4.450596] Code: 04 f5 20 28 ef 81 48 89 c6 39 55 30 76 93 89 d0 48 c1 e0 04 48 03 83 f8 05 00 00 48 8b 00 42 8b 3c 28 48 8b 43 58 48 8b 04 f8 <48> 8b b8 98 00 00 00 4c 0f a3 37 72 42 f0 4c 0f ab 37 66 8b b8 f6 [ 4.453132] RSP: 0018:ffffc900023b3cd8 EFLAGS: 00010286 [ 4.454061] RAX: 0000000000000000 RBX: ffff888174448000 RCX: 0000000000000001 [ 4.456480] RDX: 0000000000000001 RSI: ffffe8feffc506c0 RDI: 0000000000000001 [ 4.458750] RBP: ffff88810722d008 R08: ffff88817647a880 R09: 0000000000000002 [ 4.464580] R10: ffffc900023b3c10 R11: 0000000000000004 R12: ffff888174448538 [ 4.467803] R13: 0000000000000004 R14: 0000000000000001 R15: 0000000000000001 [ 4.469220] FS: 0000000000000000(0000) GS:ffff88817bac0000(0000) knlGS:0000000000000000 [ 4.471554] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 4.472464] CR2: 0000000000000098 CR3: 0000000174e4e001 CR4: 0000000000760ee0 [ 4.474264] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 4.476007] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 4.477061] PKRU: 55555554 [ 4.477464] Call Trace: [ 4.478731] blk_mq_init_allocated_queue+0x36a/0x3ad [ 4.479595] blk_mq_init_queue+0x32/0x4e [ 4.480178] nvme_validate_ns+0x98/0x623 [nvme_core] [ 4.480963] ? nvme_submit_sync_cmd+0x1b/0x20 [nvme_core] [ 4.481685] ? nvme_identify_ctrl.isra.8+0x70/0xa0 [nvme_core] [ 4.482601] nvme_scan_work+0x23a/0x29b [nvme_core] [ 4.483269] ? _raw_spin_unlock_irqrestore+0x25/0x38 [ 4.483930] ? try_to_wake_up+0x38d/0x3b3 [ 4.484478] ? process_one_work+0x179/0x2fc [ 4.485118] process_one_work+0x1d3/0x2fc [ 4.485655] ? rescuer_thread+0x2ae/0x2ae [ 4.486196] worker_thread+0x1e9/0x2be [ 4.486841] kthread+0x115/0x11d [ 4.487294] ? kthread_park+0x76/0x76 [ 4.487784] ret_from_fork+0x3a/0x50 [ 4.488322] Modules linked in: nvme nvme_core qemu_fw_cfg virtio_scsi ip_tables [ 4.489428] Dumping ftrace buffer: [ 4.489939] (ftrace buffer empty) [ 4.490492] CR2: 0000000000000098 [ 4.491052] ---[ end trace 03cd268ad5a86ff7 ]--- Cc: Christoph Hellwig <hch@lst.de> Cc: linux-nvme@lists.infradead.org Cc: David Milburn <dmilburn@redhat.com> Signed-off-by:
Ming Lei <ming.lei@redhat.com> Signed-off-by:
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Dennis Zhou authored
I was a little overzealous in removing the rcu_read_lock() call from blkcg_bio_issue_check() and it broke blk-throttle. Put it back. Fixes: e35403a034bf ("blkcg: associate blkg when associating a device") Signed-off-by:Dennis Zhou <dennis@kernel.org> Signed-off-by:
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Josef Bacik authored
Now that we have this common helper, convert io-latency over to use it as well. Signed-off-by:
Josef Bacik <josef@toxicpanda.com> Signed-off-by:
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Josef Bacik authored
Now that we have rq_qos_wait() in place, convert wbt_wait() over to using it with it's specific callbacks. Signed-off-by:
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Josef Bacik authored
Originally when I split out the common code from blk-wbt into rq_qos I left the wbt_wait() where it was and simply copied and modified it slightly to work for io-latency. However they are both basically the same thing, and as time has gone on wbt_wait() has ended up much smarter and kinder than it was when I copied it into io-latency, which means io-latency has lost out on these improvements. Since they are the same thing essentially except for a few minor things, create rq_qos_wait() that replicates what wbt_wait() currently does with callbacks that can be passed in for the snowflakes to do their own thing as appropriate. Signed-off-by:
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Dennis Zhou authored
blkg reference counting now uses percpu_ref rather than atomic_t. Let's make this consistent with css_tryget. This renames blkg_try_get to blkg_tryget and now returns a bool rather than the blkg or %NULL. Signed-off-by:
Tejun Heo <tj@kernel.org> Signed-off-by:
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Dennis Zhou authored
Every bio is now associated with a blkg putting blkg_get, blkg_try_get, and blkg_put on the hot path. Switch over the refcnt in blkg to use percpu_ref. Signed-off-by:
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Dennis Zhou authored
Now that a bio only holds a blkg reference, so clean up is simply putting back that reference. Remove bio_disassociate_task() as it just calls bio_disassociate_blkg() and call the latter directly. Signed-off-by:
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Dennis Zhou authored
The previous patch in this series removed carrying around a pointer to the css in blkg. However, the blkg association logic still relied on taking a reference on the css to ensure we wouldn't fail in getting a reference for the blkg. Here the implicit dependency on the css is removed. The association continues to rely on the tryget logic walking up the blkg tree. This streamlines the three ways that association can happen: normal, swap, and writeback. Signed-off-by:
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Dennis Zhou authored
Prior patches ensured that any bio that interacts with a request_queue is properly associated with a blkg. This makes bio->bi_css unnecessary as blkg maintains a reference to blkcg already. This removes the bio field bi_css and transfers corresponding uses to access via bi_blkg. Signed-off-by:
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Dennis Zhou authored
One of the goals of this series is to remove a separate reference to the css of the bio. This can and should be accessed via bio_blkcg(). In this patch, wbc_init_bio() now requires a bio to have a device associated with it. Signed-off-by:
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Dennis Zhou authored
A prior patch in this series added blkg association to bios issued by cgroups. There are two other paths that we want to attribute work back to the appropriate cgroup: swap and writeback. Here we modify the way swap tags bios to include the blkg. Writeback will be tackle in the next patch. Signed-off-by:
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Dennis Zhou authored
bio_issue_init among other things initializes the timestamp for an IO. Rather than have this logic handled by policies, this consolidates it to be on the init paths (normal, clone, bounce clone). Signed-off-by:
Liu Bo <bo.liu@linux.alibaba.com> Reviewed-by:
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Dennis Zhou authored
Previously, blkg association was handled by controller specific code in blk-throttle and blk-iolatency. However, because a blkg represents a relationship between a blkcg and a request_queue, it makes sense to keep the blkg->q and bio->bi_disk->queue consistent. This patch moves association into the bio_set_dev macro(). This should cover the majority of cases where the device is set/changed keeping the two pointers consistent. Fallback code is added to blkcg_bio_issue_check() to catch any missing paths. Signed-off-by:
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Dennis Zhou authored
The next patch changes the macro bio_set_dev() to associate a bio with a blkg based on the device set. However, dm creates a static bio to be used as the basis for cloning empty flush bios on creation. The bio_set_dev() call in alloc_dev() will cause problems with the next patch adding association to bio_set_dev() because the call is before the bdev is associated with a gendisk (bd_disk is %NULL). To get around this, set the device on the static bio every time and use that to clone to the other bios. Signed-off-by:
Mike Snitzer <snitzer@redhat.com> Cc: Alasdair Kergon <agk@redhat.com> Signed-off-by:
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Dennis Zhou authored
There are 3 ways blkg association can happen: association with the current css, with the page css (swap), or from the wbc css (writeback). This patch handles how association is done for the first case where we are associating bsaed on the current css. If there is already a blkg associated, the css will be reused and association will be redone as the request_queue may have changed. Signed-off-by:
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Dennis Zhou authored
There are several scenarios where blkg_lookup_create() can fail such as the blkcg dying, request_queue is dying, or simply being OOM. Most handle this by simply falling back to the q->root_blkg and calling it a day. This patch implements the notion of closest blkg. During blkg_lookup_create(), if it fails to create, return the closest blkg found or the q->root_blkg. blkg_try_get_closest() is introduced and used during association so a bio is always attached to a blkg. Signed-off-by:
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Dennis Zhou authored
To know when to create a blkg, the general pattern is to do a blkg_lookup() and if that fails, lock and do the lookup again, and if that fails finally create. It doesn't make much sense for everyone who wants to do creation to write this themselves. This changes blkg_lookup_create() to do locking and implement this pattern. The old blkg_lookup_create() is renamed to __blkg_lookup_create(). If a call site wants to do its own error handling or already owns the queue lock, they can use __blkg_lookup_create(). This will be used in upcoming patches. Signed-off-by:
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Dennis Zhou authored
The bio_blkcg() function turns out to be inconsistent and consequently dangerous to use. The first part returns a blkcg where a reference is owned by the bio meaning it does not need to be rcu protected. However, the third case, the last line, is problematic: return css_to_blkcg(task_css(current, io_cgrp_id)); This can race against task migration and the cgroup dying. It is also semantically different as it must be called rcu protected and is susceptible to failure when trying to get a reference to it. This patch adds association ahead of calling bio_blkcg() rather than after. This makes association a required and explicit step along the code paths for calling bio_blkcg(). In blk-iolatency, association is moved above the bio_blkcg() call to ensure it will not return %NULL. BFQ uses the old bio_blkcg() function, but I do not want to address it in this series due to the complexity. I have created a private version documenting the inconsistency and noting not to use it. Signed-off-by:
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Jens Axboe authored
We only support polling if we have poll queues now, but the flag is being set by default. Remove the default QUEUE_FLAG_POLL setting, we'll set it in blk_mq_init_allocated_queue() if we have poll queues available for this device. Fixes: 6544d229 ("block: enable polling by default if a poll map is initalized") Reported-by:
Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by:
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- 04 Dec, 2018 13 commits
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Christoph Hellwig authored
If the user did setup polling in the driver we should not require another know in the block layer to enable it. Reviewed-by:
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Christoph Hellwig authored
This avoids having to have differnet mq_ops for different setups with or without poll queues. Reviewed-by:
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Christoph Hellwig authored
This was intended to support users like nvme multipath, but is just getting in the way and adding another indirect call. Reviewed-by:
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Christoph Hellwig authored
The ->poll_fn has been stale for a while, as a lot of places check for mq ops. But there is no real point in it anyway, as we don't even use the multipath code for subsystems without multiple ports, which is usually what we do high performance I/O to. If it really becomes an issue we should rework the nvme code to also skip the multipath code for any private namespace, even if that could mean some trouble when rescanning. Reviewed-by:
Keith Busch <keith.busch@intel.com> Reviewed-by:
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Christoph Hellwig authored
The code was always a bit of a hack that digs far too much into RDMA core internals. Lets kick it out and reimplement proper dedicated poll queues as needed. Signed-off-by:
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Christoph Hellwig authored
Now that we can't poll regular, interrupt driven I/O queues there is almost nothing that can race with an interrupt. The only possible other contexts polling a CQ are the error handler and queue shutdown, and both are so far off in the slow path that we can simply use the big hammer of disabling interrupts. With that we can stop taking the cq_lock for normal queues. Reviewed-by:
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Christoph Hellwig authored
This is the last place outside of nvme_irq that handles CQEs from interrupt context, and thus is in the way of removing the cq_lock for normal queues, and avoiding lockdep warnings on the poll queues, for which we already take it without IRQ disabling. Reviewed-by:
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Christoph Hellwig authored
Pass the opcode for the delete SQ/CQ command as an argument instead of the somewhat confusing pass loop. Signed-off-by:
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Christoph Hellwig authored
We have three places that can poll for I/O completions on a normal interrupt-enabled queue. All of them are in slow path code, so consolidate them to a single helper that uses spin_lock_irqsave and removes the fast path cqe_pending check. Reviewed-by:
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Christoph Hellwig authored
This will allow us to simplify both the regular NVMe interrupt handler and the upcoming aio poll code. In addition to that the separate queues are generally a good idea for performance reasons. Reviewed-by:
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Christoph Hellwig authored
Use a bit flag to mark if the SQ was allocated from the CMB, and clean up the surrounding code a bit. Reviewed-by:
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Christoph Hellwig authored
This gets rid of all the messing with cq_vector and the ->polled field by using an atomic bitop to mark the queue enabled or not. Signed-off-by:
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Christoph Hellwig authored
Having another indirect all in the fast path doesn't really help in our post-spectre world. Also having too many queue type is just going to create confusion, so I'd rather manage them centrally. Note that the queue type naming and ordering changes a bit - the first index now is the default queue for everything not explicitly marked, the optional ones are read and poll queues. Reviewed-by:
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