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linux-next/fs/io-wq.h

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io-wq: small threadpool implementation for io_uring This adds support for io-wq, a smaller and specialized thread pool implementation. This is meant to replace workqueues for io_uring. Among the reasons for this addition are: - We can assign memory context smarter and more persistently if we manage the life time of threads. - We can drop various work-arounds we have in io_uring, like the async_list. - We can implement hashed work insertion, to manage concurrency of buffered writes without needing a) an extra workqueue, or b) needlessly making the concurrency of said workqueue very low which hurts performance of multiple buffered file writers. - We can implement cancel through signals, for cancelling interruptible work like read/write (or send/recv) to/from sockets. - We need the above cancel for being able to assign and use file tables from a process. - We can implement a more thorough cancel operation in general. - We need it to move towards a syslet/threadlet model for even faster async execution. For that we need to take ownership of the used threads. This list is just off the top of my head. Performance should be the same, or better, at least that's what I've seen in my testing. io-wq supports basic NUMA functionality, setting up a pool per node. io-wq hooks up to the scheduler schedule in/out just like workqueue and uses that to drive the need for more/less workers. Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-23 00:25:58 +08:00
#ifndef INTERNAL_IO_WQ_H
#define INTERNAL_IO_WQ_H
io_uring: move io identity items into separate struct io-wq contains a pointer to the identity, which we just hold in io_kiocb for now. This is in preparation for putting this outside io_kiocb. The only exception is struct files_struct, which we'll need different rules for to avoid a circular dependency. No functional changes in this patch. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-15 00:48:51 +08:00
#include <linux/io_uring.h>
io-wq: small threadpool implementation for io_uring This adds support for io-wq, a smaller and specialized thread pool implementation. This is meant to replace workqueues for io_uring. Among the reasons for this addition are: - We can assign memory context smarter and more persistently if we manage the life time of threads. - We can drop various work-arounds we have in io_uring, like the async_list. - We can implement hashed work insertion, to manage concurrency of buffered writes without needing a) an extra workqueue, or b) needlessly making the concurrency of said workqueue very low which hurts performance of multiple buffered file writers. - We can implement cancel through signals, for cancelling interruptible work like read/write (or send/recv) to/from sockets. - We need the above cancel for being able to assign and use file tables from a process. - We can implement a more thorough cancel operation in general. - We need it to move towards a syslet/threadlet model for even faster async execution. For that we need to take ownership of the used threads. This list is just off the top of my head. Performance should be the same, or better, at least that's what I've seen in my testing. io-wq supports basic NUMA functionality, setting up a pool per node. io-wq hooks up to the scheduler schedule in/out just like workqueue and uses that to drive the need for more/less workers. Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-23 00:25:58 +08:00
struct io_wq;
enum {
IO_WQ_WORK_CANCEL = 1,
io-wq: compact io-wq flags numbers Renumerate IO_WQ flags, so they take adjacent bits Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-25 23:20:53 +08:00
IO_WQ_WORK_HASHED = 2,
IO_WQ_WORK_UNBOUND = 4,
IO_WQ_WORK_NO_CANCEL = 8,
IO_WQ_WORK_CONCURRENT = 16,
io-wq: small threadpool implementation for io_uring This adds support for io-wq, a smaller and specialized thread pool implementation. This is meant to replace workqueues for io_uring. Among the reasons for this addition are: - We can assign memory context smarter and more persistently if we manage the life time of threads. - We can drop various work-arounds we have in io_uring, like the async_list. - We can implement hashed work insertion, to manage concurrency of buffered writes without needing a) an extra workqueue, or b) needlessly making the concurrency of said workqueue very low which hurts performance of multiple buffered file writers. - We can implement cancel through signals, for cancelling interruptible work like read/write (or send/recv) to/from sockets. - We need the above cancel for being able to assign and use file tables from a process. - We can implement a more thorough cancel operation in general. - We need it to move towards a syslet/threadlet model for even faster async execution. For that we need to take ownership of the used threads. This list is just off the top of my head. Performance should be the same, or better, at least that's what I've seen in my testing. io-wq supports basic NUMA functionality, setting up a pool per node. io-wq hooks up to the scheduler schedule in/out just like workqueue and uses that to drive the need for more/less workers. Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-23 00:25:58 +08:00
io_uring: pass required context in as flags We have a number of bits that decide what context to inherit. Set up io-wq flags for these instead. This is in preparation for always having the various members set, but not always needing them for all requests. No intended functional changes in this patch. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-14 23:23:55 +08:00
IO_WQ_WORK_FILES = 32,
IO_WQ_WORK_FS = 64,
IO_WQ_WORK_MM = 128,
IO_WQ_WORK_CREDS = 256,
IO_WQ_WORK_BLKCG = 512,
io_uring: unify fsize with def->work_flags This one was missed in the earlier conversion, should be included like any of the other IO identity flags. Make sure we restore to RLIM_INIFITY when dropping the personality again. Fixes: 98447d65b4a7 ("io_uring: move io identity items into separate struct") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-21 04:28:41 +08:00
IO_WQ_WORK_FSIZE = 1024,
io_uring: pass required context in as flags We have a number of bits that decide what context to inherit. Set up io-wq flags for these instead. This is in preparation for always having the various members set, but not always needing them for all requests. No intended functional changes in this patch. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-14 23:23:55 +08:00
io-wq: small threadpool implementation for io_uring This adds support for io-wq, a smaller and specialized thread pool implementation. This is meant to replace workqueues for io_uring. Among the reasons for this addition are: - We can assign memory context smarter and more persistently if we manage the life time of threads. - We can drop various work-arounds we have in io_uring, like the async_list. - We can implement hashed work insertion, to manage concurrency of buffered writes without needing a) an extra workqueue, or b) needlessly making the concurrency of said workqueue very low which hurts performance of multiple buffered file writers. - We can implement cancel through signals, for cancelling interruptible work like read/write (or send/recv) to/from sockets. - We need the above cancel for being able to assign and use file tables from a process. - We can implement a more thorough cancel operation in general. - We need it to move towards a syslet/threadlet model for even faster async execution. For that we need to take ownership of the used threads. This list is just off the top of my head. Performance should be the same, or better, at least that's what I've seen in my testing. io-wq supports basic NUMA functionality, setting up a pool per node. io-wq hooks up to the scheduler schedule in/out just like workqueue and uses that to drive the need for more/less workers. Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-23 00:25:58 +08:00
IO_WQ_HASH_SHIFT = 24, /* upper 8 bits are used for hash key */
};
enum io_wq_cancel {
IO_WQ_CANCEL_OK, /* cancelled before started */
IO_WQ_CANCEL_RUNNING, /* found, running, and attempted cancelled */
IO_WQ_CANCEL_NOTFOUND, /* work not found */
};
io-wq: shrink io_wq_work a bit Currently we're using 40 bytes for the io_wq_work structure, and 16 of those is the doubly link list node. We don't need doubly linked lists, we always add to tail to keep things ordered, and any other use case is list traversal with deletion. For the deletion case, we can easily support any node deletion by keeping track of the previous entry. This shrinks io_wq_work to 32 bytes, and subsequently io_kiock from io_uring to 216 to 208 bytes. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-27 02:59:32 +08:00
struct io_wq_work_node {
struct io_wq_work_node *next;
};
struct io_wq_work_list {
struct io_wq_work_node *first;
struct io_wq_work_node *last;
};
io-wq: handle hashed writes in chains We always punt async buffered writes to an io-wq helper, as the core kernel does not have IOCB_NOWAIT support for that. Most buffered async writes complete very quickly, as it's just a copy operation. This means that doing multiple locking roundtrips on the shared wqe lock for each buffered write is wasteful. Additionally, buffered writes are hashed work items, which means that any buffered write to a given file is serialized. Keep identicaly hashed work items contiguously in @wqe->work_list, and track a tail for each hash bucket. On dequeue of a hashed item, splice all of the same hash in one go using the tracked tail. Until the batch is done, the caller doesn't have to synchronize with the wqe or worker locks again. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-24 03:57:22 +08:00
static inline void wq_list_add_after(struct io_wq_work_node *node,
struct io_wq_work_node *pos,
struct io_wq_work_list *list)
{
struct io_wq_work_node *next = pos->next;
pos->next = node;
node->next = next;
if (!next)
list->last = node;
}
io-wq: shrink io_wq_work a bit Currently we're using 40 bytes for the io_wq_work structure, and 16 of those is the doubly link list node. We don't need doubly linked lists, we always add to tail to keep things ordered, and any other use case is list traversal with deletion. For the deletion case, we can easily support any node deletion by keeping track of the previous entry. This shrinks io_wq_work to 32 bytes, and subsequently io_kiock from io_uring to 216 to 208 bytes. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-27 02:59:32 +08:00
static inline void wq_list_add_tail(struct io_wq_work_node *node,
struct io_wq_work_list *list)
{
if (!list->first) {
io-wq: briefly spin for new work after finishing work To avoid going to sleep only to get woken shortly thereafter, spin briefly for new work upon completion of work. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-12-08 12:06:46 +08:00
list->last = node;
WRITE_ONCE(list->first, node);
io-wq: shrink io_wq_work a bit Currently we're using 40 bytes for the io_wq_work structure, and 16 of those is the doubly link list node. We don't need doubly linked lists, we always add to tail to keep things ordered, and any other use case is list traversal with deletion. For the deletion case, we can easily support any node deletion by keeping track of the previous entry. This shrinks io_wq_work to 32 bytes, and subsequently io_kiock from io_uring to 216 to 208 bytes. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-27 02:59:32 +08:00
} else {
list->last->next = node;
list->last = node;
}
io_uring: fix io_wqe->work_list corruption For the first time a req punted to io-wq, we'll initialize io_wq_work's list to be NULL, then insert req to io_wqe->work_list. If this req is not inserted into tail of io_wqe->work_list, this req's io_wq_work list will point to another req's io_wq_work. For splitted bio case, this req maybe inserted to io_wqe->work_list repeatedly, once we insert it to tail of io_wqe->work_list for the second time, now io_wq_work->list->next will be invalid pointer, which then result in many strang error, panic, kernel soft-lockup, rcu stall, etc. In my vm, kernel doest not have commit cc29e1bf0d63f7 ("block: disable iopoll for split bio"), below fio job can reproduce this bug steadily: [global] name=iouring-sqpoll-iopoll-1 ioengine=io_uring iodepth=128 numjobs=1 thread rw=randread direct=1 registerfiles=1 hipri=1 bs=4m size=100M runtime=120 time_based group_reporting randrepeat=0 [device] directory=/home/feiman.wxg/mntpoint/ # an ext4 mount point If we have commit cc29e1bf0d63f7 ("block: disable iopoll for split bio"), there will no splitted bio case for polled io, but I think we still to need to fix this list corruption, it also should maybe go to stable branchs. To fix this corruption, if a req is inserted into tail of io_wqe->work_list, initialize req->io_wq_work->list->next to bu NULL. Cc: stable@vger.kernel.org Signed-off-by: Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-18 15:26:48 +08:00
node->next = NULL;
io-wq: shrink io_wq_work a bit Currently we're using 40 bytes for the io_wq_work structure, and 16 of those is the doubly link list node. We don't need doubly linked lists, we always add to tail to keep things ordered, and any other use case is list traversal with deletion. For the deletion case, we can easily support any node deletion by keeping track of the previous entry. This shrinks io_wq_work to 32 bytes, and subsequently io_kiock from io_uring to 216 to 208 bytes. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-27 02:59:32 +08:00
}
io-wq: handle hashed writes in chains We always punt async buffered writes to an io-wq helper, as the core kernel does not have IOCB_NOWAIT support for that. Most buffered async writes complete very quickly, as it's just a copy operation. This means that doing multiple locking roundtrips on the shared wqe lock for each buffered write is wasteful. Additionally, buffered writes are hashed work items, which means that any buffered write to a given file is serialized. Keep identicaly hashed work items contiguously in @wqe->work_list, and track a tail for each hash bucket. On dequeue of a hashed item, splice all of the same hash in one go using the tracked tail. Until the batch is done, the caller doesn't have to synchronize with the wqe or worker locks again. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-24 03:57:22 +08:00
static inline void wq_list_cut(struct io_wq_work_list *list,
struct io_wq_work_node *last,
io-wq: shrink io_wq_work a bit Currently we're using 40 bytes for the io_wq_work structure, and 16 of those is the doubly link list node. We don't need doubly linked lists, we always add to tail to keep things ordered, and any other use case is list traversal with deletion. For the deletion case, we can easily support any node deletion by keeping track of the previous entry. This shrinks io_wq_work to 32 bytes, and subsequently io_kiock from io_uring to 216 to 208 bytes. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-27 02:59:32 +08:00
struct io_wq_work_node *prev)
{
io-wq: handle hashed writes in chains We always punt async buffered writes to an io-wq helper, as the core kernel does not have IOCB_NOWAIT support for that. Most buffered async writes complete very quickly, as it's just a copy operation. This means that doing multiple locking roundtrips on the shared wqe lock for each buffered write is wasteful. Additionally, buffered writes are hashed work items, which means that any buffered write to a given file is serialized. Keep identicaly hashed work items contiguously in @wqe->work_list, and track a tail for each hash bucket. On dequeue of a hashed item, splice all of the same hash in one go using the tracked tail. Until the batch is done, the caller doesn't have to synchronize with the wqe or worker locks again. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-24 03:57:22 +08:00
/* first in the list, if prev==NULL */
if (!prev)
WRITE_ONCE(list->first, last->next);
else
prev->next = last->next;
if (last == list->last)
io-wq: shrink io_wq_work a bit Currently we're using 40 bytes for the io_wq_work structure, and 16 of those is the doubly link list node. We don't need doubly linked lists, we always add to tail to keep things ordered, and any other use case is list traversal with deletion. For the deletion case, we can easily support any node deletion by keeping track of the previous entry. This shrinks io_wq_work to 32 bytes, and subsequently io_kiock from io_uring to 216 to 208 bytes. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-27 02:59:32 +08:00
list->last = prev;
io-wq: handle hashed writes in chains We always punt async buffered writes to an io-wq helper, as the core kernel does not have IOCB_NOWAIT support for that. Most buffered async writes complete very quickly, as it's just a copy operation. This means that doing multiple locking roundtrips on the shared wqe lock for each buffered write is wasteful. Additionally, buffered writes are hashed work items, which means that any buffered write to a given file is serialized. Keep identicaly hashed work items contiguously in @wqe->work_list, and track a tail for each hash bucket. On dequeue of a hashed item, splice all of the same hash in one go using the tracked tail. Until the batch is done, the caller doesn't have to synchronize with the wqe or worker locks again. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-24 03:57:22 +08:00
last->next = NULL;
}
static inline void wq_list_del(struct io_wq_work_list *list,
struct io_wq_work_node *node,
struct io_wq_work_node *prev)
{
wq_list_cut(list, node, prev);
io-wq: shrink io_wq_work a bit Currently we're using 40 bytes for the io_wq_work structure, and 16 of those is the doubly link list node. We don't need doubly linked lists, we always add to tail to keep things ordered, and any other use case is list traversal with deletion. For the deletion case, we can easily support any node deletion by keeping track of the previous entry. This shrinks io_wq_work to 32 bytes, and subsequently io_kiock from io_uring to 216 to 208 bytes. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-27 02:59:32 +08:00
}
#define wq_list_for_each(pos, prv, head) \
for (pos = (head)->first, prv = NULL; pos; prv = pos, pos = (pos)->next)
io-wq: briefly spin for new work after finishing work To avoid going to sleep only to get woken shortly thereafter, spin briefly for new work upon completion of work. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-12-08 12:06:46 +08:00
#define wq_list_empty(list) (READ_ONCE((list)->first) == NULL)
io-wq: shrink io_wq_work a bit Currently we're using 40 bytes for the io_wq_work structure, and 16 of those is the doubly link list node. We don't need doubly linked lists, we always add to tail to keep things ordered, and any other use case is list traversal with deletion. For the deletion case, we can easily support any node deletion by keeping track of the previous entry. This shrinks io_wq_work to 32 bytes, and subsequently io_kiock from io_uring to 216 to 208 bytes. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-27 02:59:32 +08:00
#define INIT_WQ_LIST(list) do { \
(list)->first = NULL; \
(list)->last = NULL; \
} while (0)
io-wq: small threadpool implementation for io_uring This adds support for io-wq, a smaller and specialized thread pool implementation. This is meant to replace workqueues for io_uring. Among the reasons for this addition are: - We can assign memory context smarter and more persistently if we manage the life time of threads. - We can drop various work-arounds we have in io_uring, like the async_list. - We can implement hashed work insertion, to manage concurrency of buffered writes without needing a) an extra workqueue, or b) needlessly making the concurrency of said workqueue very low which hurts performance of multiple buffered file writers. - We can implement cancel through signals, for cancelling interruptible work like read/write (or send/recv) to/from sockets. - We need the above cancel for being able to assign and use file tables from a process. - We can implement a more thorough cancel operation in general. - We need it to move towards a syslet/threadlet model for even faster async execution. For that we need to take ownership of the used threads. This list is just off the top of my head. Performance should be the same, or better, at least that's what I've seen in my testing. io-wq supports basic NUMA functionality, setting up a pool per node. io-wq hooks up to the scheduler schedule in/out just like workqueue and uses that to drive the need for more/less workers. Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-23 00:25:58 +08:00
struct io_wq_work {
io_uring: Fix ->data corruption on re-enqueue work->data and work->list are shared in union. io_wq_assign_next() sets ->data if a req having a linked_timeout, but then io-wq may want to use work->list, e.g. to do re-enqueue of a request, so corrupting ->data. ->data is not necessary, just remove it and extract linked_timeout through @link_list. Fixes: 60cf46ae6054 ("io-wq: hash dependent work") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-23 05:23:29 +08:00
struct io_wq_work_node list;
io_uring: move io identity items into separate struct io-wq contains a pointer to the identity, which we just hold in io_kiocb for now. This is in preparation for putting this outside io_kiocb. The only exception is struct files_struct, which we'll need different rules for to avoid a circular dependency. No functional changes in this patch. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-15 00:48:51 +08:00
struct io_identity *identity;
io-wq: shrink io_wq_work a bit Currently we're using 40 bytes for the io_wq_work structure, and 16 of those is the doubly link list node. We don't need doubly linked lists, we always add to tail to keep things ordered, and any other use case is list traversal with deletion. For the deletion case, we can easily support any node deletion by keeping track of the previous entry. This shrinks io_wq_work to 32 bytes, and subsequently io_kiock from io_uring to 216 to 208 bytes. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-27 02:59:32 +08:00
unsigned flags;
io-wq: small threadpool implementation for io_uring This adds support for io-wq, a smaller and specialized thread pool implementation. This is meant to replace workqueues for io_uring. Among the reasons for this addition are: - We can assign memory context smarter and more persistently if we manage the life time of threads. - We can drop various work-arounds we have in io_uring, like the async_list. - We can implement hashed work insertion, to manage concurrency of buffered writes without needing a) an extra workqueue, or b) needlessly making the concurrency of said workqueue very low which hurts performance of multiple buffered file writers. - We can implement cancel through signals, for cancelling interruptible work like read/write (or send/recv) to/from sockets. - We need the above cancel for being able to assign and use file tables from a process. - We can implement a more thorough cancel operation in general. - We need it to move towards a syslet/threadlet model for even faster async execution. For that we need to take ownership of the used threads. This list is just off the top of my head. Performance should be the same, or better, at least that's what I've seen in my testing. io-wq supports basic NUMA functionality, setting up a pool per node. io-wq hooks up to the scheduler schedule in/out just like workqueue and uses that to drive the need for more/less workers. Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-23 00:25:58 +08:00
};
io-wq: handle hashed writes in chains We always punt async buffered writes to an io-wq helper, as the core kernel does not have IOCB_NOWAIT support for that. Most buffered async writes complete very quickly, as it's just a copy operation. This means that doing multiple locking roundtrips on the shared wqe lock for each buffered write is wasteful. Additionally, buffered writes are hashed work items, which means that any buffered write to a given file is serialized. Keep identicaly hashed work items contiguously in @wqe->work_list, and track a tail for each hash bucket. On dequeue of a hashed item, splice all of the same hash in one go using the tracked tail. Until the batch is done, the caller doesn't have to synchronize with the wqe or worker locks again. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-24 03:57:22 +08:00
static inline struct io_wq_work *wq_next_work(struct io_wq_work *work)
{
if (!work->list.next)
return NULL;
return container_of(work->list.next, struct io_wq_work, list);
}
io_uring/io-wq: forward submission ref to async First it changes io-wq interfaces. It replaces {get,put}_work() with free_work(), which guaranteed to be called exactly once. It also enforces free_work() callback to be non-NULL. io_uring follows the changes and instead of putting a submission reference in io_put_req_async_completion(), it will be done in io_free_work(). As removes io_get_work() with corresponding refcount_inc(), the ref balance is maintained. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-04 21:14:12 +08:00
typedef void (free_work_fn)(struct io_wq_work *);
io-wq: return next work from ->do_work() directly It's easier to return next work from ->do_work() than having an in-out argument. Looks nicer and easier to compile. Also, merge io_wq_assign_next() into its only user. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-25 23:20:54 +08:00
typedef struct io_wq_work *(io_wq_work_fn)(struct io_wq_work *);
io_wq: add get/put_work handlers to io_wq_create() For cancellation, we need to ensure that the work item stays valid for as long as ->cur_work is valid. Right now we can't safely dereference the work item even under the wqe->lock, because while the ->cur_work pointer will remain valid, the work could be completing and be freed in parallel. Only invoke ->get/put_work() on items we know that the caller queued themselves. Add IO_WQ_WORK_INTERNAL for io-wq to use, which is needed when we're queueing a flush item, for instance. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-13 13:31:31 +08:00
io-wq: have io_wq_create() take a 'data' argument We currently pass in 4 arguments outside of the bounded size. In preparation for adding one more argument, let's bundle them up in a struct to make it more readable. No functional changes in this patch. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-25 23:49:20 +08:00
struct io_wq_data {
struct user_struct *user;
io_wq: add per-wq work handler instead of per work io_uring is the only user of io-wq, and now it uses only io-wq callback for all its requests, namely io_wq_submit_work(). Instead of storing work->runner callback in each instance of io_wq_work, keep it in io-wq itself. pros: - reduces io_wq_work size - more robust -- ->func won't be invalidated with mem{cpy,set}(req) - helps other work Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-09 02:08:20 +08:00
io_wq_work_fn *do_work;
io_uring/io-wq: forward submission ref to async First it changes io-wq interfaces. It replaces {get,put}_work() with free_work(), which guaranteed to be called exactly once. It also enforces free_work() callback to be non-NULL. io_uring follows the changes and instead of putting a submission reference in io_put_req_async_completion(), it will be done in io_free_work(). As removes io_get_work() with corresponding refcount_inc(), the ref balance is maintained. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-04 21:14:12 +08:00
free_work_fn *free_work;
io-wq: have io_wq_create() take a 'data' argument We currently pass in 4 arguments outside of the bounded size. In preparation for adding one more argument, let's bundle them up in a struct to make it more readable. No functional changes in this patch. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-25 23:49:20 +08:00
};
struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data);
io-wq: allow grabbing existing io-wq Export a helper to attach to an existing io-wq, rather than setting up a new one. This is doable now that we have reference counted io_wq's. Reported-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-01-28 08:15:47 +08:00
bool io_wq_get(struct io_wq *wq, struct io_wq_data *data);
io-wq: small threadpool implementation for io_uring This adds support for io-wq, a smaller and specialized thread pool implementation. This is meant to replace workqueues for io_uring. Among the reasons for this addition are: - We can assign memory context smarter and more persistently if we manage the life time of threads. - We can drop various work-arounds we have in io_uring, like the async_list. - We can implement hashed work insertion, to manage concurrency of buffered writes without needing a) an extra workqueue, or b) needlessly making the concurrency of said workqueue very low which hurts performance of multiple buffered file writers. - We can implement cancel through signals, for cancelling interruptible work like read/write (or send/recv) to/from sockets. - We need the above cancel for being able to assign and use file tables from a process. - We can implement a more thorough cancel operation in general. - We need it to move towards a syslet/threadlet model for even faster async execution. For that we need to take ownership of the used threads. This list is just off the top of my head. Performance should be the same, or better, at least that's what I've seen in my testing. io-wq supports basic NUMA functionality, setting up a pool per node. io-wq hooks up to the scheduler schedule in/out just like workqueue and uses that to drive the need for more/less workers. Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-23 00:25:58 +08:00
void io_wq_destroy(struct io_wq *wq);
void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work);
io-wq: split hashing and enqueueing It's a preparation patch removing io_wq_enqueue_hashed(), which now should be done by io_wq_hash_work() + io_wq_enqueue(). Also, set hash value for dependant works, and do it as late as possible, because req->file can be unavailable before. This hash will be ignored by io-wq. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-14 05:31:04 +08:00
void io_wq_hash_work(struct io_wq_work *work, void *val);
static inline bool io_wq_is_hashed(struct io_wq_work *work)
{
return work->flags & IO_WQ_WORK_HASHED;
}
io-wq: small threadpool implementation for io_uring This adds support for io-wq, a smaller and specialized thread pool implementation. This is meant to replace workqueues for io_uring. Among the reasons for this addition are: - We can assign memory context smarter and more persistently if we manage the life time of threads. - We can drop various work-arounds we have in io_uring, like the async_list. - We can implement hashed work insertion, to manage concurrency of buffered writes without needing a) an extra workqueue, or b) needlessly making the concurrency of said workqueue very low which hurts performance of multiple buffered file writers. - We can implement cancel through signals, for cancelling interruptible work like read/write (or send/recv) to/from sockets. - We need the above cancel for being able to assign and use file tables from a process. - We can implement a more thorough cancel operation in general. - We need it to move towards a syslet/threadlet model for even faster async execution. For that we need to take ownership of the used threads. This list is just off the top of my head. Performance should be the same, or better, at least that's what I've seen in my testing. io-wq supports basic NUMA functionality, setting up a pool per node. io-wq hooks up to the scheduler schedule in/out just like workqueue and uses that to drive the need for more/less workers. Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-23 00:25:58 +08:00
io_uring: support for generic async request cancel This adds support for IORING_OP_ASYNC_CANCEL, which will attempt to cancel requests that have been punted to async context and are now in-flight. This works for regular read/write requests to files, as long as they haven't been started yet. For socket based IO (or things like accept4(2)), we can cancel work that is already running as well. To cancel a request, the sqe must have ->addr set to the user_data of the request it wishes to cancel. If the request is cancelled successfully, the original request is completed with -ECANCELED and the cancel request is completed with a result of 0. If the request was already running, the original may or may not complete in error. The cancel request will complete with -EALREADY for that case. And finally, if the request to cancel wasn't found, the cancel request is completed with -ENOENT. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-29 11:49:21 +08:00
typedef bool (work_cancel_fn)(struct io_wq_work *, void *);
enum io_wq_cancel io_wq_cancel_cb(struct io_wq *wq, work_cancel_fn *cancel,
io-wq: add an option to cancel all matched reqs This adds support for cancelling all io-wq works matching a predicate. It isn't used yet, so no change in observable behaviour. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-15 15:24:03 +08:00
void *data, bool cancel_all);
io_uring: support for generic async request cancel This adds support for IORING_OP_ASYNC_CANCEL, which will attempt to cancel requests that have been punted to async context and are now in-flight. This works for regular read/write requests to files, as long as they haven't been started yet. For socket based IO (or things like accept4(2)), we can cancel work that is already running as well. To cancel a request, the sqe must have ->addr set to the user_data of the request it wishes to cancel. If the request is cancelled successfully, the original request is completed with -ECANCELED and the cancel request is completed with a result of 0. If the request was already running, the original may or may not complete in error. The cancel request will complete with -EALREADY for that case. And finally, if the request to cancel wasn't found, the cancel request is completed with -ENOENT. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-29 11:49:21 +08:00
io_uring: use io-wq manager as backup task if task is exiting If the original task is (or has) exited, then the task work will not get queued properly. Allow for using the io-wq manager task to queue this work for execution, and ensure that the io-wq manager notices and runs this work if woken up (or exiting). Reported-by: Dan Melnic <dmm@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-04 01:26:26 +08:00
struct task_struct *io_wq_get_task(struct io_wq *wq);
io-wq: small threadpool implementation for io_uring This adds support for io-wq, a smaller and specialized thread pool implementation. This is meant to replace workqueues for io_uring. Among the reasons for this addition are: - We can assign memory context smarter and more persistently if we manage the life time of threads. - We can drop various work-arounds we have in io_uring, like the async_list. - We can implement hashed work insertion, to manage concurrency of buffered writes without needing a) an extra workqueue, or b) needlessly making the concurrency of said workqueue very low which hurts performance of multiple buffered file writers. - We can implement cancel through signals, for cancelling interruptible work like read/write (or send/recv) to/from sockets. - We need the above cancel for being able to assign and use file tables from a process. - We can implement a more thorough cancel operation in general. - We need it to move towards a syslet/threadlet model for even faster async execution. For that we need to take ownership of the used threads. This list is just off the top of my head. Performance should be the same, or better, at least that's what I've seen in my testing. io-wq supports basic NUMA functionality, setting up a pool per node. io-wq hooks up to the scheduler schedule in/out just like workqueue and uses that to drive the need for more/less workers. Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-23 00:25:58 +08:00
#if defined(CONFIG_IO_WQ)
extern void io_wq_worker_sleeping(struct task_struct *);
extern void io_wq_worker_running(struct task_struct *);
#else
static inline void io_wq_worker_sleeping(struct task_struct *tsk)
{
}
static inline void io_wq_worker_running(struct task_struct *tsk)
{
}
io-wq: re-add io_wq_current_is_worker() This reverts commit 8cdda87a4414, we now have several use csaes for this helper. Reinstate it. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-12-18 05:13:37 +08:00
#endif
io-wq: small threadpool implementation for io_uring This adds support for io-wq, a smaller and specialized thread pool implementation. This is meant to replace workqueues for io_uring. Among the reasons for this addition are: - We can assign memory context smarter and more persistently if we manage the life time of threads. - We can drop various work-arounds we have in io_uring, like the async_list. - We can implement hashed work insertion, to manage concurrency of buffered writes without needing a) an extra workqueue, or b) needlessly making the concurrency of said workqueue very low which hurts performance of multiple buffered file writers. - We can implement cancel through signals, for cancelling interruptible work like read/write (or send/recv) to/from sockets. - We need the above cancel for being able to assign and use file tables from a process. - We can implement a more thorough cancel operation in general. - We need it to move towards a syslet/threadlet model for even faster async execution. For that we need to take ownership of the used threads. This list is just off the top of my head. Performance should be the same, or better, at least that's what I've seen in my testing. io-wq supports basic NUMA functionality, setting up a pool per node. io-wq hooks up to the scheduler schedule in/out just like workqueue and uses that to drive the need for more/less workers. Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-23 00:25:58 +08:00
io-wq: re-add io_wq_current_is_worker() This reverts commit 8cdda87a4414, we now have several use csaes for this helper. Reinstate it. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-12-18 05:13:37 +08:00
static inline bool io_wq_current_is_worker(void)
{
return in_task() && (current->flags & PF_IO_WORKER);
}
#endif
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