MFV r296505: 6531 Provide mechanism to artificially limit disk performance
Reviewed by: Paul Dagnelie <pcd@delphix.com> Reviewed by: Matthew Ahrens <mahrens@delphix.com> Reviewed by: George Wilson <george.wilson@delphix.com> Approved by: Dan McDonald <danmcd@omniti.com> Author: Prakash Surya <prakash.surya@delphix.com> illumos/illumos-gate@97e8130957
This commit is contained in:
Alexander Motin
commit
1b63fd68f4
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=296510
@ -20,7 +20,7 @@
|
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*/
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/*
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* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
|
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* Copyright (c) 2012 by Delphix. All rights reserved.
|
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* Copyright (c) 2012, 2015 by Delphix. All rights reserved.
|
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*/
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|
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/*
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@ -229,21 +229,57 @@ usage(void)
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"\t\tall records if 'all' is specificed.\n"
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"\n"
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"\tzinject -p <function name> pool\n"
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"\n"
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"\t\tInject a panic fault at the specified function. Only \n"
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"\t\tfunctions which call spa_vdev_config_exit(), or \n"
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"\t\tspa_vdev_exit() will trigger a panic.\n"
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"\n"
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"\tzinject -d device [-e errno] [-L <nvlist|uber|pad1|pad2>] [-F]\n"
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"\t [-T <read|write|free|claim|all> pool\n"
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"\n"
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"\t\tInject a fault into a particular device or the device's\n"
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"\t\tlabel. Label injection can either be 'nvlist', 'uber',\n "
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"\t\t'pad1', or 'pad2'.\n"
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"\t\t'errno' can be 'nxio' (the default), 'io', or 'dtl'.\n"
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"\n"
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"\tzinject -d device -A <degrade|fault> pool\n"
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"\n"
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"\t\tPerform a specific action on a particular device\n"
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"\n"
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"\tzinject -d device -D latency:lanes pool\n"
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"\n"
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"\t\tAdd an artificial delay to IO requests on a particular\n"
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"\t\tdevice, such that the requests take a minimum of 'latency'\n"
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"\t\tmilliseconds to complete. Each delay has an associated\n"
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"\t\tnumber of 'lanes' which defines the number of concurrent\n"
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"\t\tIO requests that can be processed.\n"
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"\n"
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"\t\tFor example, with a single lane delay of 10 ms (-D 10:1),\n"
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"\t\tthe device will only be able to service a single IO request\n"
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"\t\tat a time with each request taking 10 ms to complete. So,\n"
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"\t\tif only a single request is submitted every 10 ms, the\n"
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"\t\taverage latency will be 10 ms; but if more than one request\n"
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"\t\tis submitted every 10 ms, the average latency will be more\n"
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"\t\tthan 10 ms.\n"
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"\n"
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"\t\tSimilarly, if a delay of 10 ms is specified to have two\n"
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"\t\tlanes (-D 10:2), then the device will be able to service\n"
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"\t\ttwo requests at a time, each with a minimum latency of\n"
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"\t\t10 ms. So, if two requests are submitted every 10 ms, then\n"
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"\t\tthe average latency will be 10 ms; but if more than two\n"
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"\t\trequests are submitted every 10 ms, the average latency\n"
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"\t\twill be more than 10 ms.\n"
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"\n"
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"\t\tAlso note, these delays are additive. So two invocations\n"
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"\t\tof '-D 10:1', is roughly equivalent to a single invocation\n"
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"\t\tof '-D 10:2'. This also means, one can specify multiple\n"
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"\t\tlanes with differing target latencies. For example, an\n"
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"\t\tinvocation of '-D 10:1' followed by '-D 25:2' will\n"
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"\t\tcreate 3 lanes on the device; one lane with a latency\n"
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"\t\tof 10 ms and two lanes with a 25 ms latency.\n"
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"\n"
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"\tzinject -I [-s <seconds> | -g <txgs>] pool\n"
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"\n"
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"\t\tCause the pool to stop writing blocks yet not\n"
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"\t\treport errors for a duration. Simulates buggy hardware\n"
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"\t\tthat fails to honor cache flush requests.\n"
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@ -357,6 +393,9 @@ print_device_handler(int id, const char *pool, zinject_record_t *record,
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if (record->zi_guid == 0 || record->zi_func[0] != '\0')
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return (0);
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if (record->zi_cmd == ZINJECT_DELAY_IO)
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return (0);
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if (*count == 0) {
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(void) printf("%3s %-15s %s\n", "ID", "POOL", "GUID");
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(void) printf("--- --------------- ----------------\n");
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@ -370,6 +409,35 @@ print_device_handler(int id, const char *pool, zinject_record_t *record,
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return (0);
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}
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static int
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print_delay_handler(int id, const char *pool, zinject_record_t *record,
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void *data)
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{
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int *count = data;
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if (record->zi_guid == 0 || record->zi_func[0] != '\0')
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return (0);
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if (record->zi_cmd != ZINJECT_DELAY_IO)
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return (0);
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if (*count == 0) {
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(void) printf("%3s %-15s %-15s %-15s %s\n",
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"ID", "POOL", "DELAY (ms)", "LANES", "GUID");
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(void) printf("--- --------------- --------------- "
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"--------------- ----------------\n");
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}
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*count += 1;
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(void) printf("%3d %-15s %-15llu %-15llu %llx\n", id, pool,
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(u_longlong_t)NSEC2MSEC(record->zi_timer),
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(u_longlong_t)record->zi_nlanes,
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(u_longlong_t)record->zi_guid);
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return (0);
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}
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static int
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print_panic_handler(int id, const char *pool, zinject_record_t *record,
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void *data)
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@ -407,6 +475,13 @@ print_all_handlers(void)
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count = 0;
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}
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(void) iter_handlers(print_delay_handler, &count);
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if (count > 0) {
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total += count;
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(void) printf("\n");
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count = 0;
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}
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(void) iter_handlers(print_data_handler, &count);
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if (count > 0) {
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total += count;
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@ -549,6 +624,35 @@ perform_action(const char *pool, zinject_record_t *record, int cmd)
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return (1);
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}
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static int
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parse_delay(char *str, uint64_t *delay, uint64_t *nlanes)
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{
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unsigned long scan_delay;
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unsigned long scan_nlanes;
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if (sscanf(str, "%lu:%lu", &scan_delay, &scan_nlanes) != 2)
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return (1);
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/*
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* We explicitly disallow a delay of zero here, because we key
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* off this value being non-zero in translate_device(), to
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* determine if the fault is a ZINJECT_DELAY_IO fault or not.
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*/
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if (scan_delay == 0)
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return (1);
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/*
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* The units for the CLI delay parameter is milliseconds, but
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* the data passed to the kernel is interpreted as nanoseconds.
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* Thus we scale the milliseconds to nanoseconds here, and this
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* nanosecond value is used to pass the delay to the kernel.
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*/
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*delay = MSEC2NSEC(scan_delay);
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*nlanes = scan_nlanes;
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return (0);
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}
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int
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main(int argc, char **argv)
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{
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@ -632,8 +736,9 @@ main(int argc, char **argv)
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device = optarg;
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break;
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case 'D':
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record.zi_timer = strtoull(optarg, &end, 10);
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if (errno != 0 || *end != '\0') {
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ret = parse_delay(optarg, &record.zi_timer,
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&record.zi_nlanes);
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if (ret != 0) {
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(void) fprintf(stderr, "invalid i/o delay "
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"value: '%s'\n", optarg);
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usage();
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37
sys/cddl/compat/opensolaris/sys/callo.h
Normal file
37
sys/cddl/compat/opensolaris/sys/callo.h
Normal file
@ -0,0 +1,37 @@
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/*-
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* Copyright (c) 2016 Alexander Motin <mav@FreeBSD.org>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
|
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
|
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#ifndef _OPENSOLARIS_SYS_CALLO_H_
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#define _OPENSOLARIS_SYS_CALLO_H_
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#include_next <sys/callout.h>
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#define CALLOUT_REALTIME 0 /* realtime callout type */
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#define CALLOUT_NORMAL 1 /* normal callout type */
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#endif /* !_OPENSOLARIS_SYS_CALLO_H_ */
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@ -42,6 +42,9 @@
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#define delay(x) pause("soldelay", (x))
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#define timeout_generic(type, fn, arg, t, r, f) \
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timeout(fn, arg, t / (NANOSEC/hz) + 1)
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#endif /* _KERNEL */
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#endif /* _OPENSOLARIS_SYS_SYSTM_H_ */
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@ -94,10 +94,8 @@ extern "C" {
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#include <sys/sunddi.h>
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#ifdef illumos
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#include <sys/cyclic.h>
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#include <sys/callo.h>
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#else /* FreeBSD */
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#include <sys/callout.h>
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#endif
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#include <sys/callo.h>
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#include <sys/disp.h>
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#include <machine/stdarg.h>
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@ -308,6 +308,7 @@ typedef struct zinject_record {
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uint32_t zi_iotype;
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int32_t zi_duration;
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uint64_t zi_timer;
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uint64_t zi_nlanes;
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uint32_t zi_cmd;
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uint32_t zi_pad;
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} zinject_record_t;
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@ -455,6 +455,7 @@ struct zio {
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uint64_t io_offset;
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hrtime_t io_timestamp;
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hrtime_t io_target_timestamp;
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avl_node_t io_queue_node;
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avl_node_t io_offset_node;
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@ -548,6 +549,8 @@ extern int zio_wait(zio_t *zio);
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extern void zio_nowait(zio_t *zio);
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extern void zio_execute(zio_t *zio);
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extern void zio_interrupt(zio_t *zio);
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extern void zio_delay_init(zio_t *zio);
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extern void zio_delay_interrupt(zio_t *zio);
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extern zio_t *zio_walk_parents(zio_t *cio);
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extern zio_t *zio_walk_children(zio_t *pio);
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@ -609,7 +612,7 @@ extern int zio_handle_fault_injection(zio_t *zio, int error);
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extern int zio_handle_device_injection(vdev_t *vd, zio_t *zio, int error);
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extern int zio_handle_label_injection(zio_t *zio, int error);
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extern void zio_handle_ignored_writes(zio_t *zio);
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extern uint64_t zio_handle_io_delay(zio_t *zio);
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extern hrtime_t zio_handle_io_delay(zio_t *zio);
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/*
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* Checksum ereport functions
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@ -20,7 +20,7 @@
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*/
|
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/*
|
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* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
|
||||
* Copyright (c) 2012, 2014 by Delphix. All rights reserved.
|
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* Copyright (c) 2012, 2015 by Delphix. All rights reserved.
|
||||
* Copyright 2013 Nexenta Systems, Inc. All rights reserved.
|
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* Copyright (c) 2013 Joyent, Inc. All rights reserved.
|
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*/
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@ -691,7 +691,7 @@ vdev_disk_io_intr(buf_t *bp)
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kmem_free(vb, sizeof (vdev_buf_t));
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zio_interrupt(zio);
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zio_delay_interrupt(zio);
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}
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static void
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@ -797,6 +797,7 @@ vdev_disk_io_start(zio_t *zio)
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}
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ASSERT(zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE);
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zio->io_target_timestamp = zio_handle_io_delay(zio);
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vb = kmem_alloc(sizeof (vdev_buf_t), KM_SLEEP);
|
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|
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|
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@ -20,7 +20,7 @@
|
||||
*/
|
||||
/*
|
||||
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
|
||||
* Copyright (c) 2011, 2014 by Delphix. All rights reserved.
|
||||
* Copyright (c) 2011, 2015 by Delphix. All rights reserved.
|
||||
*/
|
||||
|
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#include <sys/zfs_context.h>
|
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@ -188,6 +188,7 @@ vdev_file_io_start(zio_t *zio)
|
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}
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|
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ASSERT(zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE);
|
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zio->io_target_timestamp = zio_handle_io_delay(zio);
|
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|
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zio->io_error = vn_rdwr(zio->io_type == ZIO_TYPE_READ ?
|
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UIO_READ : UIO_WRITE, vp, zio->io_data, zio->io_size,
|
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@ -196,7 +197,7 @@ vdev_file_io_start(zio_t *zio)
|
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if (resid != 0 && zio->io_error == 0)
|
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zio->io_error = ENOSPC;
|
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|
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zio_interrupt(zio);
|
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zio_delay_interrupt(zio);
|
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|
||||
#ifdef illumos
|
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VERIFY3U(taskq_dispatch(system_taskq, vdev_file_io_strategy, bp,
|
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|
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@ -885,7 +885,7 @@ vdev_geom_io_intr(struct bio *bp)
|
||||
break;
|
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}
|
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g_destroy_bio(bp);
|
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zio_interrupt(zio);
|
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zio_delay_interrupt(zio);
|
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}
|
||||
|
||||
static void
|
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@ -948,6 +948,7 @@ vdev_geom_io_start(zio_t *zio)
|
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switch (zio->io_type) {
|
||||
case ZIO_TYPE_READ:
|
||||
case ZIO_TYPE_WRITE:
|
||||
zio->io_target_timestamp = zio_handle_io_delay(zio);
|
||||
bp->bio_cmd = zio->io_type == ZIO_TYPE_READ ? BIO_READ : BIO_WRITE;
|
||||
bp->bio_data = zio->io_data;
|
||||
bp->bio_offset = zio->io_offset;
|
||||
|
||||
@ -871,9 +871,6 @@ vdev_queue_io_done(zio_t *zio)
|
||||
vdev_queue_t *vq = &zio->io_vd->vdev_queue;
|
||||
zio_t *nio;
|
||||
|
||||
if (zio_injection_enabled)
|
||||
delay(SEC_TO_TICK(zio_handle_io_delay(zio)));
|
||||
|
||||
mutex_enter(&vq->vq_lock);
|
||||
|
||||
vdev_queue_pending_remove(vq, zio);
|
||||
|
||||
@ -1442,6 +1442,58 @@ zio_interrupt(zio_t *zio)
|
||||
zio_taskq_dispatch(zio, ZIO_TASKQ_INTERRUPT, B_FALSE);
|
||||
}
|
||||
|
||||
void
|
||||
zio_delay_interrupt(zio_t *zio)
|
||||
{
|
||||
/*
|
||||
* The timeout_generic() function isn't defined in userspace, so
|
||||
* rather than trying to implement the function, the zio delay
|
||||
* functionality has been disabled for userspace builds.
|
||||
*/
|
||||
|
||||
#ifdef _KERNEL
|
||||
/*
|
||||
* If io_target_timestamp is zero, then no delay has been registered
|
||||
* for this IO, thus jump to the end of this function and "skip" the
|
||||
* delay; issuing it directly to the zio layer.
|
||||
*/
|
||||
if (zio->io_target_timestamp != 0) {
|
||||
hrtime_t now = gethrtime();
|
||||
|
||||
if (now >= zio->io_target_timestamp) {
|
||||
/*
|
||||
* This IO has already taken longer than the target
|
||||
* delay to complete, so we don't want to delay it
|
||||
* any longer; we "miss" the delay and issue it
|
||||
* directly to the zio layer. This is likely due to
|
||||
* the target latency being set to a value less than
|
||||
* the underlying hardware can satisfy (e.g. delay
|
||||
* set to 1ms, but the disks take 10ms to complete an
|
||||
* IO request).
|
||||
*/
|
||||
|
||||
DTRACE_PROBE2(zio__delay__miss, zio_t *, zio,
|
||||
hrtime_t, now);
|
||||
|
||||
zio_interrupt(zio);
|
||||
} else {
|
||||
hrtime_t diff = zio->io_target_timestamp - now;
|
||||
|
||||
DTRACE_PROBE3(zio__delay__hit, zio_t *, zio,
|
||||
hrtime_t, now, hrtime_t, diff);
|
||||
|
||||
(void) timeout_generic(CALLOUT_NORMAL,
|
||||
(void (*)(void *))zio_interrupt, zio, diff, 1, 0);
|
||||
}
|
||||
|
||||
return;
|
||||
}
|
||||
#endif
|
||||
|
||||
DTRACE_PROBE1(zio__delay__skip, zio_t *, zio);
|
||||
zio_interrupt(zio);
|
||||
}
|
||||
|
||||
/*
|
||||
* Execute the I/O pipeline until one of the following occurs:
|
||||
*
|
||||
|
||||
@ -20,7 +20,7 @@
|
||||
*/
|
||||
/*
|
||||
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
|
||||
* Copyright (c) 2012, 2014 by Delphix. All rights reserved.
|
||||
* Copyright (c) 2012, 2015 by Delphix. All rights reserved.
|
||||
*/
|
||||
|
||||
/*
|
||||
@ -49,15 +49,53 @@
|
||||
|
||||
uint32_t zio_injection_enabled;
|
||||
|
||||
/*
|
||||
* Data describing each zinject handler registered on the system, and
|
||||
* contains the list node linking the handler in the global zinject
|
||||
* handler list.
|
||||
*/
|
||||
typedef struct inject_handler {
|
||||
int zi_id;
|
||||
spa_t *zi_spa;
|
||||
zinject_record_t zi_record;
|
||||
uint64_t *zi_lanes;
|
||||
int zi_next_lane;
|
||||
list_node_t zi_link;
|
||||
} inject_handler_t;
|
||||
|
||||
/*
|
||||
* List of all zinject handlers registered on the system, protected by
|
||||
* the inject_lock defined below.
|
||||
*/
|
||||
static list_t inject_handlers;
|
||||
|
||||
/*
|
||||
* This protects insertion into, and traversal of, the inject handler
|
||||
* list defined above; as well as the inject_delay_count. Any time a
|
||||
* handler is inserted or removed from the list, this lock should be
|
||||
* taken as a RW_WRITER; and any time traversal is done over the list
|
||||
* (without modification to it) this lock should be taken as a RW_READER.
|
||||
*/
|
||||
static krwlock_t inject_lock;
|
||||
|
||||
/*
|
||||
* This holds the number of zinject delay handlers that have been
|
||||
* registered on the system. It is protected by the inject_lock defined
|
||||
* above. Thus modifications to this count must be a RW_WRITER of the
|
||||
* inject_lock, and reads of this count must be (at least) a RW_READER
|
||||
* of the lock.
|
||||
*/
|
||||
static int inject_delay_count = 0;
|
||||
|
||||
/*
|
||||
* This lock is used only in zio_handle_io_delay(), refer to the comment
|
||||
* in that function for more details.
|
||||
*/
|
||||
static kmutex_t inject_delay_mtx;
|
||||
|
||||
/*
|
||||
* Used to assign unique identifying numbers to each new zinject handler.
|
||||
*/
|
||||
static int inject_next_id = 1;
|
||||
|
||||
/*
|
||||
@ -360,32 +398,164 @@ spa_handle_ignored_writes(spa_t *spa)
|
||||
rw_exit(&inject_lock);
|
||||
}
|
||||
|
||||
uint64_t
|
||||
hrtime_t
|
||||
zio_handle_io_delay(zio_t *zio)
|
||||
{
|
||||
vdev_t *vd = zio->io_vd;
|
||||
inject_handler_t *handler;
|
||||
uint64_t seconds = 0;
|
||||
|
||||
if (zio_injection_enabled == 0)
|
||||
return (0);
|
||||
inject_handler_t *min_handler = NULL;
|
||||
hrtime_t min_target = 0;
|
||||
|
||||
rw_enter(&inject_lock, RW_READER);
|
||||
|
||||
for (handler = list_head(&inject_handlers); handler != NULL;
|
||||
handler = list_next(&inject_handlers, handler)) {
|
||||
/*
|
||||
* inject_delay_count is a subset of zio_injection_enabled that
|
||||
* is only incremented for delay handlers. These checks are
|
||||
* mainly added to remind the reader why we're not explicitly
|
||||
* checking zio_injection_enabled like the other functions.
|
||||
*/
|
||||
IMPLY(inject_delay_count > 0, zio_injection_enabled > 0);
|
||||
IMPLY(zio_injection_enabled == 0, inject_delay_count == 0);
|
||||
|
||||
/*
|
||||
* If there aren't any inject delay handlers registered, then we
|
||||
* can short circuit and simply return 0 here. A value of zero
|
||||
* informs zio_delay_interrupt() that this request should not be
|
||||
* delayed. This short circuit keeps us from acquiring the
|
||||
* inject_delay_mutex unnecessarily.
|
||||
*/
|
||||
if (inject_delay_count == 0) {
|
||||
rw_exit(&inject_lock);
|
||||
return (0);
|
||||
}
|
||||
|
||||
/*
|
||||
* Each inject handler has a number of "lanes" associated with
|
||||
* it. Each lane is able to handle requests independently of one
|
||||
* another, and at a latency defined by the inject handler
|
||||
* record's zi_timer field. Thus if a handler in configured with
|
||||
* a single lane with a 10ms latency, it will delay requests
|
||||
* such that only a single request is completed every 10ms. So,
|
||||
* if more than one request is attempted per each 10ms interval,
|
||||
* the average latency of the requests will be greater than
|
||||
* 10ms; but if only a single request is submitted each 10ms
|
||||
* interval the average latency will be 10ms.
|
||||
*
|
||||
* We need to acquire this mutex to prevent multiple concurrent
|
||||
* threads being assigned to the same lane of a given inject
|
||||
* handler. The mutex allows us to perform the following two
|
||||
* operations atomically:
|
||||
*
|
||||
* 1. determine the minimum handler and minimum target
|
||||
* value of all the possible handlers
|
||||
* 2. update that minimum handler's lane array
|
||||
*
|
||||
* Without atomicity, two (or more) threads could pick the same
|
||||
* lane in step (1), and then conflict with each other in step
|
||||
* (2). This could allow a single lane handler to process
|
||||
* multiple requests simultaneously, which shouldn't be possible.
|
||||
*/
|
||||
mutex_enter(&inject_delay_mtx);
|
||||
|
||||
for (inject_handler_t *handler = list_head(&inject_handlers);
|
||||
handler != NULL; handler = list_next(&inject_handlers, handler)) {
|
||||
if (handler->zi_record.zi_cmd != ZINJECT_DELAY_IO)
|
||||
continue;
|
||||
|
||||
if (vd->vdev_guid == handler->zi_record.zi_guid) {
|
||||
seconds = handler->zi_record.zi_timer;
|
||||
break;
|
||||
if (vd->vdev_guid != handler->zi_record.zi_guid)
|
||||
continue;
|
||||
|
||||
/*
|
||||
* Defensive; should never happen as the array allocation
|
||||
* occurs prior to inserting this handler on the list.
|
||||
*/
|
||||
ASSERT3P(handler->zi_lanes, !=, NULL);
|
||||
|
||||
/*
|
||||
* This should never happen, the zinject command should
|
||||
* prevent a user from setting an IO delay with zero lanes.
|
||||
*/
|
||||
ASSERT3U(handler->zi_record.zi_nlanes, !=, 0);
|
||||
|
||||
ASSERT3U(handler->zi_record.zi_nlanes, >,
|
||||
handler->zi_next_lane);
|
||||
|
||||
/*
|
||||
* We want to issue this IO to the lane that will become
|
||||
* idle the soonest, so we compare the soonest this
|
||||
* specific handler can complete the IO with all other
|
||||
* handlers, to find the lowest value of all possible
|
||||
* lanes. We then use this lane to submit the request.
|
||||
*
|
||||
* Since each handler has a constant value for its
|
||||
* delay, we can just use the "next" lane for that
|
||||
* handler; as it will always be the lane with the
|
||||
* lowest value for that particular handler (i.e. the
|
||||
* lane that will become idle the soonest). This saves a
|
||||
* scan of each handler's lanes array.
|
||||
*
|
||||
* There's two cases to consider when determining when
|
||||
* this specific IO request should complete. If this
|
||||
* lane is idle, we want to "submit" the request now so
|
||||
* it will complete after zi_timer milliseconds. Thus,
|
||||
* we set the target to now + zi_timer.
|
||||
*
|
||||
* If the lane is busy, we want this request to complete
|
||||
* zi_timer milliseconds after the lane becomes idle.
|
||||
* Since the 'zi_lanes' array holds the time at which
|
||||
* each lane will become idle, we use that value to
|
||||
* determine when this request should complete.
|
||||
*/
|
||||
hrtime_t idle = handler->zi_record.zi_timer + gethrtime();
|
||||
hrtime_t busy = handler->zi_record.zi_timer +
|
||||
handler->zi_lanes[handler->zi_next_lane];
|
||||
hrtime_t target = MAX(idle, busy);
|
||||
|
||||
if (min_handler == NULL) {
|
||||
min_handler = handler;
|
||||
min_target = target;
|
||||
continue;
|
||||
}
|
||||
|
||||
ASSERT3P(min_handler, !=, NULL);
|
||||
ASSERT3U(min_target, !=, 0);
|
||||
|
||||
/*
|
||||
* We don't yet increment the "next lane" variable since
|
||||
* we still might find a lower value lane in another
|
||||
* handler during any remaining iterations. Once we're
|
||||
* sure we've selected the absolute minimum, we'll claim
|
||||
* the lane and increment the handler's "next lane"
|
||||
* field below.
|
||||
*/
|
||||
|
||||
if (target < min_target) {
|
||||
min_handler = handler;
|
||||
min_target = target;
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* 'min_handler' will be NULL if no IO delays are registered for
|
||||
* this vdev, otherwise it will point to the handler containing
|
||||
* the lane that will become idle the soonest.
|
||||
*/
|
||||
if (min_handler != NULL) {
|
||||
ASSERT3U(min_target, !=, 0);
|
||||
min_handler->zi_lanes[min_handler->zi_next_lane] = min_target;
|
||||
|
||||
/*
|
||||
* If we've used all possible lanes for this handler,
|
||||
* loop back and start using the first lane again;
|
||||
* otherwise, just increment the lane index.
|
||||
*/
|
||||
min_handler->zi_next_lane = (min_handler->zi_next_lane + 1) %
|
||||
min_handler->zi_record.zi_nlanes;
|
||||
}
|
||||
|
||||
mutex_exit(&inject_delay_mtx);
|
||||
rw_exit(&inject_lock);
|
||||
return (seconds);
|
||||
|
||||
return (min_target);
|
||||
}
|
||||
|
||||
/*
|
||||
@ -409,6 +579,24 @@ zio_inject_fault(char *name, int flags, int *id, zinject_record_t *record)
|
||||
if ((error = spa_reset(name)) != 0)
|
||||
return (error);
|
||||
|
||||
if (record->zi_cmd == ZINJECT_DELAY_IO) {
|
||||
/*
|
||||
* A value of zero for the number of lanes or for the
|
||||
* delay time doesn't make sense.
|
||||
*/
|
||||
if (record->zi_timer == 0 || record->zi_nlanes == 0)
|
||||
return (SET_ERROR(EINVAL));
|
||||
|
||||
/*
|
||||
* The number of lanes is directly mapped to the size of
|
||||
* an array used by the handler. Thus, to ensure the
|
||||
* user doesn't trigger an allocation that's "too large"
|
||||
* we cap the number of lanes here.
|
||||
*/
|
||||
if (record->zi_nlanes >= UINT16_MAX)
|
||||
return (SET_ERROR(EINVAL));
|
||||
}
|
||||
|
||||
if (!(flags & ZINJECT_NULL)) {
|
||||
/*
|
||||
* spa_inject_ref() will add an injection reference, which will
|
||||
@ -420,11 +608,34 @@ zio_inject_fault(char *name, int flags, int *id, zinject_record_t *record)
|
||||
|
||||
handler = kmem_alloc(sizeof (inject_handler_t), KM_SLEEP);
|
||||
|
||||
rw_enter(&inject_lock, RW_WRITER);
|
||||
|
||||
*id = handler->zi_id = inject_next_id++;
|
||||
handler->zi_spa = spa;
|
||||
handler->zi_record = *record;
|
||||
|
||||
if (handler->zi_record.zi_cmd == ZINJECT_DELAY_IO) {
|
||||
handler->zi_lanes = kmem_zalloc(
|
||||
sizeof (*handler->zi_lanes) *
|
||||
handler->zi_record.zi_nlanes, KM_SLEEP);
|
||||
handler->zi_next_lane = 0;
|
||||
} else {
|
||||
handler->zi_lanes = NULL;
|
||||
handler->zi_next_lane = 0;
|
||||
}
|
||||
|
||||
rw_enter(&inject_lock, RW_WRITER);
|
||||
|
||||
/*
|
||||
* We can't move this increment into the conditional
|
||||
* above because we need to hold the RW_WRITER lock of
|
||||
* inject_lock, and we don't want to hold that while
|
||||
* allocating the handler's zi_lanes array.
|
||||
*/
|
||||
if (handler->zi_record.zi_cmd == ZINJECT_DELAY_IO) {
|
||||
ASSERT3S(inject_delay_count, >=, 0);
|
||||
inject_delay_count++;
|
||||
ASSERT3S(inject_delay_count, >, 0);
|
||||
}
|
||||
|
||||
*id = handler->zi_id = inject_next_id++;
|
||||
list_insert_tail(&inject_handlers, handler);
|
||||
atomic_inc_32(&zio_injection_enabled);
|
||||
|
||||
@ -502,9 +713,23 @@ zio_clear_fault(int id)
|
||||
return (SET_ERROR(ENOENT));
|
||||
}
|
||||
|
||||
if (handler->zi_record.zi_cmd == ZINJECT_DELAY_IO) {
|
||||
ASSERT3S(inject_delay_count, >, 0);
|
||||
inject_delay_count--;
|
||||
ASSERT3S(inject_delay_count, >=, 0);
|
||||
}
|
||||
|
||||
list_remove(&inject_handlers, handler);
|
||||
rw_exit(&inject_lock);
|
||||
|
||||
if (handler->zi_record.zi_cmd == ZINJECT_DELAY_IO) {
|
||||
ASSERT3P(handler->zi_lanes, !=, NULL);
|
||||
kmem_free(handler->zi_lanes, sizeof (*handler->zi_lanes) *
|
||||
handler->zi_record.zi_nlanes);
|
||||
} else {
|
||||
ASSERT3P(handler->zi_lanes, ==, NULL);
|
||||
}
|
||||
|
||||
spa_inject_delref(handler->zi_spa);
|
||||
kmem_free(handler, sizeof (inject_handler_t));
|
||||
atomic_dec_32(&zio_injection_enabled);
|
||||
@ -516,6 +741,7 @@ void
|
||||
zio_inject_init(void)
|
||||
{
|
||||
rw_init(&inject_lock, NULL, RW_DEFAULT, NULL);
|
||||
mutex_init(&inject_delay_mtx, NULL, MUTEX_DEFAULT, NULL);
|
||||
list_create(&inject_handlers, sizeof (inject_handler_t),
|
||||
offsetof(inject_handler_t, zi_link));
|
||||
}
|
||||
@ -524,5 +750,6 @@ void
|
||||
zio_inject_fini(void)
|
||||
{
|
||||
list_destroy(&inject_handlers);
|
||||
mutex_destroy(&inject_delay_mtx);
|
||||
rw_destroy(&inject_lock);
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue
Block a user