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* memory access op ideas
@ 2022-04-13 10:33 Avi Kivity
  2022-04-22 12:52 ` Hao Xu
  2022-04-22 14:50 ` Jens Axboe
  0 siblings, 2 replies; 22+ messages in thread
From: Avi Kivity @ 2022-04-13 10:33 UTC (permalink / raw)
  To: io-uring

Unfortunately, only ideas, no patches. But at least the first seems very 
easy.


- IORING_OP_MEMCPY_IMMEDIATE - copy some payload included in the op 
itself (1-8 bytes) to a user memory location specified by the op.


Linked to another op, this can generate an in-memory notification useful 
for busy-waiters or the UMWAIT instruction


This would be useful for Seastar, which looks at a timer-managed memory 
location to check when to break computation loops.


- IORING_OP_MEMCPY - asynchronously copy memory


Some CPUs include a DMA engine, and io_uring is a perfect interface to 
exercise it. It may be difficult to find space for two iovecs though.




^ permalink raw reply	[flat|nested] 22+ messages in thread

end of thread, other threads:[~2022-04-25 18:05 UTC | newest]

Thread overview: 22+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2022-04-13 10:33 memory access op ideas Avi Kivity
2022-04-22 12:52 ` Hao Xu
2022-04-22 13:24   ` Hao Xu
2022-04-22 13:38   ` Jens Axboe
2022-04-23  7:19     ` Hao Xu
2022-04-23 16:14   ` Avi Kivity
2022-04-22 14:50 ` Jens Axboe
2022-04-22 15:03   ` Jens Axboe
2022-04-23 16:30     ` Avi Kivity
2022-04-23 17:32       ` Jens Axboe
2022-04-23 18:02         ` Jens Axboe
2022-04-23 18:11           ` Jens Axboe
2022-04-22 20:03   ` Walker, Benjamin
2022-04-23 10:19     ` Pavel Begunkov
2022-04-23 13:20     ` Jens Axboe
2022-04-23 16:23   ` Avi Kivity
2022-04-23 17:30     ` Jens Axboe
2022-04-24 13:04       ` Avi Kivity
2022-04-24 13:30         ` Jens Axboe
2022-04-24 14:56           ` Avi Kivity
2022-04-25  0:45             ` Jens Axboe
2022-04-25 18:05               ` Walker, Benjamin

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