Jens Axboe 943e942e62 nvme-pci: limit max IO size and segments to avoid high order allocations ... nvme requires an sg table allocation for each request. If the request is large, then the allocation can become quite large. For instance, with our default software settings of 1280KB IO size, we'll need 10248 bytes of sg table. That turns into a 2nd order allocation, which we can't always guarantee. If we fail the allocation, blk-mq will retry it later. But there's no guarantee that we'll EVER be able to allocate that much contigious memory. Limit the IO size such that we never need more than a single page of memory. That's a lot faster and more reliable. Then back that allocation with a mempool, so that we know we'll always be able to succeed the allocation at some point. Signed-off-by: Jens Axboe <axboe@kernel.dk> Acked-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Christoph Hellwig <hch@lst.de>		2018-06-21 18:59:46 +02:00
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host	nvme-pci: limit max IO size and segments to avoid high order allocations	2018-06-21 18:59:46 +02:00
target	nvmet: reset keep alive timer in controller enable	2018-06-20 14:20:51 +02:00
Kconfig	nvme: use menu Kconfig interface	2017-10-04 09:43:57 +02:00
Makefile	nvmet: add a generic NVMe target	2016-07-05 11:30:33 -06:00