Commit 54a935a6 authored by Konrad Sztyber's avatar Konrad Sztyber Committed by Ben Walker
Browse files

bdev: cache whether IO needs to be split 



bdev_io_should_split() adds some non-zero overhead, so checking it
multiple times in an IO path is inefficient.  So, to avoid that, call
bdev_io_should_split() once during IO initialization and cache the
result in bdev_io.

Signed-off-by: default avatarKonrad Sztyber <konrad.sztyber@intel.com>
Change-Id: I1da6514d409f8a4e4bbb14722dd53b2c88988cac
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/17058


Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarAleksey Marchuk <alexeymar@nvidia.com>
parent f555961f

include/spdk/bdev_module.h

+3 −0
Original line number Diff line number Diff line
@@ -947,6 +947,9 @@ struct spdk_bdev_io { 
		/** Status for the IO */

		int8_t status;



		/** Indicates whether the IO is split */

		bool split;



		/** bdev allocated memory associated with this request */

		void *buf;

lib/bdev/bdev.c

+6 −2
Original line number Diff line number Diff line
@@ -2923,6 +2923,8 @@ static void bdev_rw_split_get_buf_cb(struct spdk_io_channel *ch, struct spdk_bde 
static void

bdev_io_split(struct spdk_bdev_io *bdev_io)

{

	assert(bdev_io_should_split(bdev_io));



	bdev_io->u.bdev.split_current_offset_blocks = bdev_io->u.bdev.offset_blocks;

	bdev_io->u.bdev.split_remaining_num_blocks = bdev_io->u.bdev.num_blocks;

	bdev_io->u.bdev.split_outstanding = 0;
@@ -3082,7 +3084,7 @@ bdev_io_submit(struct spdk_bdev_io *bdev_io) 
			      bdev_io->u.bdev.offset_blocks, bdev_io->u.bdev.num_blocks,

			      spdk_bdev_get_name(bdev));



	if (bdev_io_should_split(bdev_io)) {

	if (bdev_io->internal.split) {

		bdev_io_split(bdev_io);

		return;

	}
@@ -3162,6 +3164,7 @@ bdev_io_init(struct spdk_bdev_io *bdev_io, 
	bdev_io->internal.memory_domain = NULL;

	bdev_io->internal.memory_domain_ctx = NULL;

	bdev_io->internal.data_transfer_cpl = NULL;

	bdev_io->internal.split = bdev_io_should_split(bdev_io);

}



static bool
@@ -6212,7 +6215,8 @@ bdev_abort_io(struct spdk_bdev_desc *desc, struct spdk_bdev_channel *channel, 
	bdev_io->type = SPDK_BDEV_IO_TYPE_ABORT;

	bdev_io_init(bdev_io, bdev, cb_arg, cb);



	if (bdev->split_on_optimal_io_boundary && bdev_io_should_split(bio_to_abort)) {

	if (bdev->split_on_optimal_io_boundary && bio_to_abort->internal.split) {

		assert(bdev_io_should_split(bio_to_abort));

		bdev_io->u.bdev.abort.bio_cb_arg = bio_to_abort;



		/* Parent abort request is not submitted directly, but to manage its