svn commit: r296617 - in head/sys/dev: nvd nvme

[Alexander Motin]

Author: mav
Date: Thu Mar 10 17:13:10 2016
New Revision: 296617
URL: https://svnweb.freebsd.org/changeset/base/296617

Log:
  Revert r292074 (by smh): Limit stripesize reported from nvd(4) to 4K
  
  I believe that this patch handled the problem from the wrong side.
  Instead of making ZFS properly handle large stripe sizes, it made
  unrelated driver to lie in reported parameters to workaround that.
  
  Alternative solution for this problem from ZFS side was committed at
  r296615.
  
  Discussed with:	smh

Modified:
  head/sys/dev/nvd/nvd.c
  head/sys/dev/nvme/nvme.h
  head/sys/dev/nvme/nvme_ns.c
  head/sys/dev/nvme/nvme_sysctl.c

Modified: head/sys/dev/nvd/nvd.c
==============================================================================
--- head/sys/dev/nvd/nvd.c	Thu Mar 10 16:59:23 2016	(r296616)
+++ head/sys/dev/nvd/nvd.c	Thu Mar 10 17:13:10 2016	(r296617)
@@ -311,7 +311,7 @@ nvd_new_disk(struct nvme_namespace *ns, 
 	disk->d_delmaxsize = (off_t)nvme_ns_get_size(ns);
 	if (disk->d_delmaxsize > nvd_delete_max)
 		disk->d_delmaxsize = nvd_delete_max;
-	disk->d_stripesize = nvme_ns_get_optimal_sector_size(ns);
+	disk->d_stripesize = nvme_ns_get_stripesize(ns);
 
 	if (TAILQ_EMPTY(&disk_head))
 		disk->d_unit = 0;

Modified: head/sys/dev/nvme/nvme.h
==============================================================================
--- head/sys/dev/nvme/nvme.h	Thu Mar 10 16:59:23 2016	(r296616)
+++ head/sys/dev/nvme/nvme.h	Thu Mar 10 17:13:10 2016	(r296617)
@@ -898,7 +898,6 @@ const char *	nvme_ns_get_serial_number(s
 const char *	nvme_ns_get_model_number(struct nvme_namespace *ns);
 const struct nvme_namespace_data *
 		nvme_ns_get_data(struct nvme_namespace *ns);
-uint32_t	nvme_ns_get_optimal_sector_size(struct nvme_namespace *ns);
 uint32_t	nvme_ns_get_stripesize(struct nvme_namespace *ns);
 
 int	nvme_ns_bio_process(struct nvme_namespace *ns, struct bio *bp,

Modified: head/sys/dev/nvme/nvme_ns.c
==============================================================================
--- head/sys/dev/nvme/nvme_ns.c	Thu Mar 10 16:59:23 2016	(r296616)
+++ head/sys/dev/nvme/nvme_ns.c	Thu Mar 10 17:13:10 2016	(r296617)
@@ -45,8 +45,6 @@ __FBSDID("$FreeBSD$");
 
 #include "nvme_private.h"
 
-extern int		nvme_max_optimal_sectorsize;
-
 static void		nvme_bio_child_inbed(struct bio *parent, int bio_error);
 static void		nvme_bio_child_done(void *arg,
 					    const struct nvme_completion *cpl);
@@ -219,22 +217,6 @@ nvme_ns_get_stripesize(struct nvme_names
 	return (ns->stripesize);
 }
 
-uint32_t
-nvme_ns_get_optimal_sector_size(struct nvme_namespace *ns)
-{
-	uint32_t stripesize;
-
-	stripesize = nvme_ns_get_stripesize(ns);
-
-	if (stripesize == 0)
-		return nvme_ns_get_sector_size(ns);
-		
-	if (nvme_max_optimal_sectorsize == 0) 
-		return (stripesize);
-
-	return (MIN(stripesize, nvme_max_optimal_sectorsize));
-}
-
 static void
 nvme_ns_bio_done(void *arg, const struct nvme_completion *status)
 {

Modified: head/sys/dev/nvme/nvme_sysctl.c
==============================================================================
--- head/sys/dev/nvme/nvme_sysctl.c	Thu Mar 10 16:59:23 2016	(r296616)
+++ head/sys/dev/nvme/nvme_sysctl.c	Thu Mar 10 17:13:10 2016	(r296617)
@@ -33,22 +33,6 @@ __FBSDID("$FreeBSD$");
 
 #include "nvme_private.h"
 
-SYSCTL_NODE(_kern, OID_AUTO, nvme, CTLFLAG_RD, 0, "NVM Express");
-/*
- * Intel NVMe controllers have a slow path for I/Os that span a 128KB
- * stripe boundary but ZFS limits ashift, which is derived from
- * d_stripesize, to 13 (8KB) so we limit the stripesize reported to
- * geom(8) to 4KB by default.
- *
- * This may result in a small number of additional I/Os to require
- * splitting in nvme(4), however the NVMe I/O path is very efficient
- * so these additional I/Os will cause very minimal (if any) difference
- * in performance or CPU utilisation.
- */
-int nvme_max_optimal_sectorsize = 1<<12;
-SYSCTL_INT(_kern_nvme, OID_AUTO, max_optimal_sectorsize, CTLFLAG_RWTUN,
-    &nvme_max_optimal_sectorsize, 0, "The maximum optimal sectorsize reported");
-
 /*
  * CTLTYPE_S64 and sysctl_handle_64 were added in r217616.  Define these
  *  explicitly here for older kernels that don't include the r217616