Commit b5f4a259 authored by Jim Harris's avatar Jim Harris
Browse files

bdev: save mgmt_ch that spdk_bdev_io was allocated from 



This avoids having to dereference the spdk_bdev_io's
channel in the spdk_bdev_free_io() path.

Cleaning up after hotplug events should ensure that
all associated bdev_ios have been freed (not just
completed) before the bdev channels have been freed,
but this patch gives us some more wiggle room in this
area.

Results in a small (1-2%) performance degradation on
a bdevperf microbenchmark, but should result in no
noticeable difference on any real world workload.

Signed-off-by: default avatarJim Harris <james.r.harris@intel.com>
Change-Id: Id8b88300fc53e8c0b83309a738a4c3bd2aeaff52

Reviewed-on: https://review.gerrithub.io/394399


Tested-by: default avatarSPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
Reviewed-by: default avatar <shuhei.matsumoto.xt@hitachi.com>
parent cd31a31f

include/spdk_internal/bdev.h

+3 −0
Original line number Diff line number Diff line
@@ -274,6 +274,9 @@ struct spdk_bdev_io { 
	/** The bdev I/O channel that this was submitted on. */

	struct spdk_bdev_channel *ch;



	/** The mgmt channel that this I/O was allocated from. */

	struct spdk_bdev_mgmt_channel *mgmt_ch;



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

	void *buf;

lib/bdev/bdev.c

+4 −2
Original line number Diff line number Diff line
@@ -283,7 +283,7 @@ spdk_bdev_io_put_buf(struct spdk_bdev_io *bdev_io) 
	assert(bdev_io->u.bdev.iovcnt == 1);



	buf = bdev_io->buf;

	ch = spdk_io_channel_get_ctx(bdev_io->ch->mgmt_channel);

	ch = bdev_io->mgmt_ch;



	if (bdev_io->buf_len <= SPDK_BDEV_SMALL_BUF_MAX_SIZE) {

		pool = g_bdev_mgr.buf_small_pool;
@@ -754,13 +754,15 @@ spdk_bdev_get_io(struct spdk_io_channel *_ch) 
		}

	}



	bdev_io->mgmt_ch = ch;



	return bdev_io;

}



static void

spdk_bdev_put_io(struct spdk_bdev_io *bdev_io)

{

	struct spdk_bdev_mgmt_channel *ch = spdk_io_channel_get_ctx(bdev_io->ch->mgmt_channel);

	struct spdk_bdev_mgmt_channel *ch = bdev_io->mgmt_ch;



	if (bdev_io->buf != NULL) {

		spdk_bdev_io_put_buf(bdev_io);