Commit 0f99700d authored by Artur Paszkiewicz's avatar Artur Paszkiewicz Committed by Jim Harris
Browse files

ftl: user write limits 



Calculates general priorities and trigger points for writers
(gc and compaction) dependent on number of free bands. GC will
be started at SPDK_FTL_LIMIT_START level, while at SPDK_FTL_LIMIT_CRIT
compaction needs to be stopped and only GC is allowed to work.
This is done to make sure FTL doesn't run out of free bands and deadlock
itself.

Signed-off-by: default avatarArtur Paszkiewicz <artur.paszkiewicz@intel.com>
Signed-off-by: default avatarKozlowski Mateusz <mateusz.kozlowski@intel.com>
Change-Id: I1aab98503c2e79e97f8e4e9fb1257530fa9770e2
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/13326


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
parent c7213b9c

include/spdk/ftl.h

+12 −0
Original line number Diff line number Diff line
@@ -18,6 +18,15 @@ extern "C" { 
struct spdk_ftl_dev;

struct ftl_io;



/* Limit thresholds */

enum {

	SPDK_FTL_LIMIT_CRIT,

	SPDK_FTL_LIMIT_HIGH,

	SPDK_FTL_LIMIT_LOW,

	SPDK_FTL_LIMIT_START,

	SPDK_FTL_LIMIT_MAX

};



struct spdk_ftl_conf {

	/* Device's name */

	char					*name;
@@ -34,6 +43,9 @@ struct spdk_ftl_conf { 
	/* IO pool size per user thread */

	size_t					user_io_pool_size;



	/* User writes limits */

	size_t			                limits[SPDK_FTL_LIMIT_MAX];



	/* FTL startup mode mask, see spdk_ftl_mode enum for possible values */

	uint32_t				mode;

lib/ftl/ftl_core.c

+26 −0
Original line number Diff line number Diff line
@@ -26,6 +26,13 @@ spdk_ftl_io_size(void) 
	return sizeof(struct ftl_io);

}



static size_t

ftl_get_limit(const struct spdk_ftl_dev *dev, int type)

{

	assert(type < SPDK_FTL_LIMIT_MAX);

	return dev->conf.limits[type];

}



static bool

ftl_shutdown_complete(struct spdk_ftl_dev *dev)

{
@@ -50,6 +57,25 @@ ftl_shutdown_complete(struct spdk_ftl_dev *dev) 
	return true;

}



void

ftl_apply_limits(struct spdk_ftl_dev *dev)

{

	size_t limit;

	int i;



	/*  Clear existing limit */

	dev->limit = SPDK_FTL_LIMIT_MAX;



	for (i = SPDK_FTL_LIMIT_CRIT; i < SPDK_FTL_LIMIT_MAX; ++i) {

		limit = ftl_get_limit(dev, i);



		if (dev->num_free <= limit) {

			dev->limit = i;

			break;

		}

	}

}



void

ftl_invalidate_addr(struct spdk_ftl_dev *dev, ftl_addr addr)

{

lib/ftl/ftl_core.h

+5 −0
Original line number Diff line number Diff line
@@ -113,6 +113,9 @@ struct spdk_ftl_dev { 
	/* Transfer unit size */

	uint64_t			xfer_size;



	/* Current user write limit */

	int				limit;



	/* Inflight IO operations */

	uint32_t			num_inflight;
@@ -137,6 +140,8 @@ struct spdk_ftl_dev { 
	TAILQ_HEAD(, ftl_io)		wr_sq;

};



void ftl_apply_limits(struct spdk_ftl_dev *dev);



void ftl_invalidate_addr(struct spdk_ftl_dev *dev, ftl_addr addr);



int ftl_core_poller(void *ctx);

lib/ftl/utils/ftl_conf.c

+9 −0
Original line number Diff line number Diff line
@@ -8,6 +8,14 @@ 
#include "ftl_core.h"



static const struct spdk_ftl_conf g_default_conf = {

	/* 2 free bands - compaction is blocked, gc only */

	.limits[SPDK_FTL_LIMIT_CRIT]	= 2,

	/* 3 free bands */

	.limits[SPDK_FTL_LIMIT_HIGH]	= 3,

	/* 4 free bands */

	.limits[SPDK_FTL_LIMIT_LOW]	= 4,

	/* 5 free bands - gc starts running */

	.limits[SPDK_FTL_LIMIT_START]	= 5,

	/* 20% spare blocks */

	.overprovisioning = 20,

	/* IO pool size per user thread (this should be adjusted to thread IO qdepth) */
@@ -105,6 +113,7 @@ ftl_conf_init_dev(struct spdk_ftl_dev *dev, const struct spdk_ftl_conf *conf) 
		return rc;

	}



	dev->limit = SPDK_FTL_LIMIT_MAX;

	return 0;

}