svn commit: r275568 - in head: sys/cam/ctl usr.sbin/ctladm
Alexander Motin
mav at FreeBSD.org
Sat Dec 6 20:39:27 UTC 2014
Author: mav
Date: Sat Dec 6 20:39:25 2014
New Revision: 275568
URL: https://svnweb.freebsd.org/changeset/base/275568
Log:
Count consecutive read requests as blocking in CTL for files and ZVOLs.
Technically read requests can be executed in any order or simultaneously
since they are not changing any data. But ZFS prefetcher goes crasy when
it receives consecutive requests from different threads. Since prefetcher
works on level of separate blocks, instead of two consecutive 128K requests
it may receive 32 8K requests in mixed order.
This patch is more workaround then a real fix, and it does not fix all of
prefetcher problems, but it improves sequential read speed by 3-4x times
in some configurations. On the other side it may hurt performance if
some backing store has no prefetch, that is why it is disabled by default
for raw devices.
MFC after: 2 weeks
Modified:
head/sys/cam/ctl/ctl.c
head/sys/cam/ctl/ctl_backend.h
head/sys/cam/ctl/ctl_backend_block.c
head/sys/cam/ctl/ctl_private.h
head/sys/cam/ctl/ctl_ser_table.c
head/usr.sbin/ctladm/ctladm.8
Modified: head/sys/cam/ctl/ctl.c
==============================================================================
--- head/sys/cam/ctl/ctl.c Sat Dec 6 20:00:08 2014 (r275567)
+++ head/sys/cam/ctl/ctl.c Sat Dec 6 20:39:25 2014 (r275568)
@@ -433,7 +433,9 @@ static int ctl_inquiry_evpd_lbp(struct c
static int ctl_inquiry_evpd(struct ctl_scsiio *ctsio);
static int ctl_inquiry_std(struct ctl_scsiio *ctsio);
static int ctl_get_lba_len(union ctl_io *io, uint64_t *lba, uint64_t *len);
-static ctl_action ctl_extent_check(union ctl_io *io1, union ctl_io *io2);
+static ctl_action ctl_extent_check(union ctl_io *io1, union ctl_io *io2,
+ bool seq);
+static ctl_action ctl_extent_check_seq(union ctl_io *io1, union ctl_io *io2);
static ctl_action ctl_check_for_blockage(struct ctl_lun *lun,
union ctl_io *pending_io, union ctl_io *ooa_io);
static ctl_action ctl_check_ooa(struct ctl_lun *lun, union ctl_io *pending_io,
@@ -4590,6 +4592,17 @@ ctl_alloc_lun(struct ctl_softc *ctl_soft
if (value != NULL && strcmp(value, "on") == 0)
lun->flags |= CTL_LUN_READONLY;
+ lun->serseq = CTL_LUN_SERSEQ_OFF;
+ if (be_lun->flags & CTL_LUN_FLAG_SERSEQ_READ)
+ lun->serseq = CTL_LUN_SERSEQ_READ;
+ value = ctl_get_opt(&be_lun->options, "serseq");
+ if (value != NULL && strcmp(value, "on") == 0)
+ lun->serseq = CTL_LUN_SERSEQ_ON;
+ else if (value != NULL && strcmp(value, "read") == 0)
+ lun->serseq = CTL_LUN_SERSEQ_READ;
+ else if (value != NULL && strcmp(value, "off") == 0)
+ lun->serseq = CTL_LUN_SERSEQ_OFF;
+
lun->ctl_softc = ctl_softc;
TAILQ_INIT(&lun->ooa_queue);
TAILQ_INIT(&lun->blocked_queue);
@@ -10752,15 +10765,15 @@ ctl_get_lba_len(union ctl_io *io, uint64
}
static ctl_action
-ctl_extent_check_lba(uint64_t lba1, uint64_t len1, uint64_t lba2, uint64_t len2)
+ctl_extent_check_lba(uint64_t lba1, uint64_t len1, uint64_t lba2, uint64_t len2,
+ bool seq)
{
uint64_t endlba1, endlba2;
- endlba1 = lba1 + len1 - 1;
+ endlba1 = lba1 + len1 - (seq ? 0 : 1);
endlba2 = lba2 + len2 - 1;
- if ((endlba1 < lba2)
- || (endlba2 < lba1))
+ if ((endlba1 < lba2) || (endlba2 < lba1))
return (CTL_ACTION_PASS);
else
return (CTL_ACTION_BLOCK);
@@ -10799,23 +10812,39 @@ ctl_extent_check_unmap(union ctl_io *io,
}
static ctl_action
-ctl_extent_check(union ctl_io *io1, union ctl_io *io2)
+ctl_extent_check(union ctl_io *io1, union ctl_io *io2, bool seq)
{
uint64_t lba1, lba2;
uint64_t len1, len2;
int retval;
- if (ctl_get_lba_len(io1, &lba1, &len1) != 0)
+ if (ctl_get_lba_len(io2, &lba2, &len2) != 0)
return (CTL_ACTION_ERROR);
- retval = ctl_extent_check_unmap(io2, lba1, len1);
+ retval = ctl_extent_check_unmap(io1, lba2, len2);
if (retval != CTL_ACTION_ERROR)
return (retval);
+ if (ctl_get_lba_len(io1, &lba1, &len1) != 0)
+ return (CTL_ACTION_ERROR);
+
+ return (ctl_extent_check_lba(lba1, len1, lba2, len2, seq));
+}
+
+static ctl_action
+ctl_extent_check_seq(union ctl_io *io1, union ctl_io *io2)
+{
+ uint64_t lba1, lba2;
+ uint64_t len1, len2;
+
+ if (ctl_get_lba_len(io1, &lba1, &len1) != 0)
+ return (CTL_ACTION_ERROR);
if (ctl_get_lba_len(io2, &lba2, &len2) != 0)
return (CTL_ACTION_ERROR);
- return (ctl_extent_check_lba(lba1, len1, lba2, len2));
+ if (lba1 + len1 == lba2)
+ return (CTL_ACTION_BLOCK);
+ return (CTL_ACTION_PASS);
}
static ctl_action
@@ -10904,12 +10933,18 @@ ctl_check_for_blockage(struct ctl_lun *l
case CTL_SER_BLOCK:
return (CTL_ACTION_BLOCK);
case CTL_SER_EXTENT:
- return (ctl_extent_check(pending_io, ooa_io));
+ return (ctl_extent_check(ooa_io, pending_io,
+ (lun->serseq == CTL_LUN_SERSEQ_ON)));
case CTL_SER_EXTENTOPT:
if ((lun->mode_pages.control_page[CTL_PAGE_CURRENT].queue_flags
& SCP_QUEUE_ALG_MASK) != SCP_QUEUE_ALG_UNRESTRICTED)
- return (ctl_extent_check(pending_io, ooa_io));
- /* FALLTHROUGH */
+ return (ctl_extent_check(ooa_io, pending_io,
+ (lun->serseq == CTL_LUN_SERSEQ_ON)));
+ return (CTL_ACTION_PASS);
+ case CTL_SER_EXTENTSEQ:
+ if (lun->serseq != CTL_LUN_SERSEQ_OFF)
+ return (ctl_extent_check_seq(ooa_io, pending_io));
+ return (CTL_ACTION_PASS);
case CTL_SER_PASS:
return (CTL_ACTION_PASS);
case CTL_SER_BLOCKOPT:
@@ -12440,7 +12475,7 @@ ctl_cmd_pattern_match(struct ctl_scsiio
return (CTL_LUN_PAT_NONE);
action = ctl_extent_check_lba(lba1, len1, desc->lba_range.lba,
- desc->lba_range.len);
+ desc->lba_range.len, FALSE);
/*
* A "pass" means that the LBA ranges don't overlap, so
* this doesn't match the user's range criteria.
Modified: head/sys/cam/ctl/ctl_backend.h
==============================================================================
--- head/sys/cam/ctl/ctl_backend.h Sat Dec 6 20:00:08 2014 (r275567)
+++ head/sys/cam/ctl/ctl_backend.h Sat Dec 6 20:39:25 2014 (r275568)
@@ -85,7 +85,8 @@ typedef enum {
CTL_LUN_FLAG_DEVID = 0x20,
CTL_LUN_FLAG_DEV_TYPE = 0x40,
CTL_LUN_FLAG_UNMAP = 0x80,
- CTL_LUN_FLAG_OFFLINE = 0x100
+ CTL_LUN_FLAG_OFFLINE = 0x100,
+ CTL_LUN_FLAG_SERSEQ_READ = 0x200
} ctl_backend_lun_flags;
#ifdef _KERNEL
Modified: head/sys/cam/ctl/ctl_backend_block.c
==============================================================================
--- head/sys/cam/ctl/ctl_backend_block.c Sat Dec 6 20:00:08 2014 (r275567)
+++ head/sys/cam/ctl/ctl_backend_block.c Sat Dec 6 20:39:25 2014 (r275568)
@@ -2204,6 +2204,8 @@ ctl_be_block_create(struct ctl_be_block_
be_lun->ctl_be_lun.flags |= CTL_LUN_FLAG_OFFLINE;
if (unmap)
be_lun->ctl_be_lun.flags |= CTL_LUN_FLAG_UNMAP;
+ if (be_lun->dispatch != ctl_be_block_dispatch_dev)
+ be_lun->ctl_be_lun.flags |= CTL_LUN_FLAG_SERSEQ_READ;
be_lun->ctl_be_lun.be_lun = be_lun;
be_lun->ctl_be_lun.maxlba = (be_lun->size_blocks == 0) ?
0 : (be_lun->size_blocks - 1);
Modified: head/sys/cam/ctl/ctl_private.h
==============================================================================
--- head/sys/cam/ctl/ctl_private.h Sat Dec 6 20:00:08 2014 (r275567)
+++ head/sys/cam/ctl/ctl_private.h Sat Dec 6 20:39:25 2014 (r275568)
@@ -97,6 +97,7 @@ typedef enum {
CTL_SER_BLOCKOPT,
CTL_SER_EXTENT,
CTL_SER_EXTENTOPT,
+ CTL_SER_EXTENTSEQ,
CTL_SER_PASS,
CTL_SER_SKIP
} ctl_serialize_action;
@@ -183,6 +184,12 @@ typedef enum {
} ctl_lun_flags;
typedef enum {
+ CTL_LUN_SERSEQ_OFF,
+ CTL_LUN_SERSEQ_READ,
+ CTL_LUN_SERSEQ_ON
+} ctl_lun_serseq;
+
+typedef enum {
CTLBLOCK_FLAG_NONE = 0x00,
CTLBLOCK_FLAG_INVALID = 0x01
} ctlblock_flags;
@@ -386,6 +393,7 @@ struct ctl_lun {
struct ctl_id target;
uint64_t lun;
ctl_lun_flags flags;
+ ctl_lun_serseq serseq;
STAILQ_HEAD(,ctl_error_desc) error_list;
uint64_t error_serial;
struct ctl_softc *ctl_softc;
Modified: head/sys/cam/ctl/ctl_ser_table.c
==============================================================================
--- head/sys/cam/ctl/ctl_ser_table.c Sat Dec 6 20:00:08 2014 (r275567)
+++ head/sys/cam/ctl/ctl_ser_table.c Sat Dec 6 20:39:25 2014 (r275568)
@@ -59,12 +59,13 @@
#define bO CTL_SER_BLOCKOPT /* Optional block */
#define xT CTL_SER_EXTENT /* Extent check */
#define xO CTL_SER_EXTENTOPT /* Optional extent check */
+#define xS CTL_SER_EXTENTSEQ /* Sequential extent check */
static ctl_serialize_action
ctl_serialize_table[CTL_SERIDX_COUNT][CTL_SERIDX_COUNT] = {
/**>IDX_ :: 2nd:TUR RD WRT UNM MDSN MDSL RQSN INQ RDCP RES LSNS FMT STR*/
/*TUR */{ pS, pS, pS, pS, bK, bK, bK, pS, pS, bK, pS, bK, bK},
-/*READ */{ pS, pS, xT, bO, bK, bK, bK, pS, pS, bK, pS, bK, bK},
+/*READ */{ pS, xS, xT, bO, bK, bK, bK, pS, pS, bK, pS, bK, bK},
/*WRITE */{ pS, xT, xT, bO, bK, bK, bK, pS, pS, bK, pS, bK, bK},
/*UNMAP */{ pS, xO, xO, pS, bK, bK, bK, pS, pS, bK, pS, bK, bK},
/*MD_SNS */{ bK, bK, bK, bK, pS, bK, bK, pS, pS, bK, pS, bK, bK},
Modified: head/usr.sbin/ctladm/ctladm.8
==============================================================================
--- head/usr.sbin/ctladm/ctladm.8 Sat Dec 6 20:00:08 2014 (r275567)
+++ head/usr.sbin/ctladm/ctladm.8 Sat Dec 6 20:39:25 2014 (r275568)
@@ -34,7 +34,7 @@
.\" $Id: //depot/users/kenm/FreeBSD-test2/usr.sbin/ctladm/ctladm.8#3 $
.\" $FreeBSD$
.\"
-.Dd December 4, 2014
+.Dd December 6, 2014
.Dt CTLADM 8
.Os
.Sh NAME
@@ -995,6 +995,13 @@ command sequence order shall be explicit
client through the selection of appropriate commands and task attributes.
The default value is "restricted". It improves data integrity, but may
introduce some additional delays.
+.It Va serseq
+Set to "on" to serialize conseсutive reads/writes.
+Set to "read" to serialize conseсutive reads.
+Set to "off" to allow them be issued in parallel.
+Parallel issue of consecutive operations may confuse logic of the
+backing file system, hurting performance; but it may improve performance
+of backing stores without prefetch/write-back.
.It Va rpm
Specifies medium rotation rate of the device: 0 -- not reported,
1 -- non-rotating (SSD), >1024 -- value in revolutions per minute.
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