+++ /dev/null
-From 8fc3662c0d81119ae3a7c3fc1c2cd441c3054905 Mon Sep 17 00:00:00 2001
-From: Sasha Levin <sashal@kernel.org>
-Date: Fri, 20 Oct 2023 12:46:05 +0100
-Subject: dm delay: for short delays, use kthread instead of timers and wq
-
-From: Christian Loehle <christian.loehle@arm.com>
-
-[ Upstream commit 70bbeb29fab09d6ea6cfe64109db60a97d84d739 ]
-
-DM delay's current design of using timers and wq to realize the delays
-is insufficient for delays below ~50ms.
-
-This commit enhances the design to use a kthread to flush the expired
-delays, trading some CPU time (in some cases) for better delay
-accuracy and delays closer to what the user requested for smaller
-delays. The new design is chosen as long as all the delays are below
-50ms.
-
-Since bios can't be completed in interrupt context using a kthread
-is probably the most reasonable way to approach this.
-
-Testing with
-echo "0 2097152 zero" | dmsetup create dm-zeros
-for i in $(seq 0 20);
-do
- echo "0 2097152 delay /dev/mapper/dm-zeros 0 $i" | dmsetup create dm-delay-${i}ms;
-done
-
-Some performance numbers for comparison, on beaglebone black (single
-core) CONFIG_HZ_1000=y:
-
-fio --name=1msread --rw=randread --bs=4k --runtime=60 --time_based \
- --filename=/dev/mapper/dm-delay-1ms
-Theoretical maximum: 1000 IOPS
-Previous: 250 IOPS
-Kthread: 500 IOPS
-
-fio --name=10msread --rw=randread --bs=4k --runtime=60 --time_based \
- --filename=/dev/mapper/dm-delay-10ms
-Theoretical maximum: 100 IOPS
-Previous: 45 IOPS
-Kthread: 50 IOPS
-
-fio --name=1mswrite --rw=randwrite --direct=1 --bs=4k --runtime=60 \
- --time_based --filename=/dev/mapper/dm-delay-1ms
-Theoretical maximum: 1000 IOPS
-Previous: 498 IOPS
-Kthread: 1000 IOPS
-
-fio --name=10mswrite --rw=randwrite --direct=1 --bs=4k --runtime=60 \
- --time_based --filename=/dev/mapper/dm-delay-10ms
-Theoretical maximum: 100 IOPS
-Previous: 90 IOPS
-Kthread: 100 IOPS
-
-(This one is just to prove the new design isn't impacting throughput,
-not really about delays):
-fio --name=10mswriteasync --rw=randwrite --direct=1 --bs=4k \
- --runtime=60 --time_based --filename=/dev/mapper/dm-delay-10ms \
- --numjobs=32 --iodepth=64 --ioengine=libaio --group_reporting
-Previous: 13.3k IOPS
-Kthread: 13.3k IOPS
-
-Signed-off-by: Christian Loehle <christian.loehle@arm.com>
-[Harshit: kthread_create error handling fix in delay_ctr]
-Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
-Signed-off-by: Mike Snitzer <snitzer@kernel.org>
-Stable-dep-of: 6fc45b6ed921 ("dm-delay: fix a race between delay_presuspend and delay_bio")
-Signed-off-by: Sasha Levin <sashal@kernel.org>
----
- drivers/md/dm-delay.c | 103 ++++++++++++++++++++++++++++++++++++------
- 1 file changed, 88 insertions(+), 15 deletions(-)
-
-diff --git a/drivers/md/dm-delay.c b/drivers/md/dm-delay.c
-index 02b8f4e818276..358e870a03a56 100644
---- a/drivers/md/dm-delay.c
-+++ b/drivers/md/dm-delay.c
-@@ -12,6 +12,7 @@
- #include <linux/blkdev.h>
- #include <linux/bio.h>
- #include <linux/slab.h>
-+#include <linux/kthread.h>
-
- #include <linux/device-mapper.h>
-
-@@ -30,6 +31,7 @@ struct delay_c {
- struct workqueue_struct *kdelayd_wq;
- struct work_struct flush_expired_bios;
- struct list_head delayed_bios;
-+ struct task_struct *worker;
- atomic_t may_delay;
-
- struct delay_class read;
-@@ -65,6 +67,44 @@ static void queue_timeout(struct delay_c *dc, unsigned long expires)
- mutex_unlock(&dc->timer_lock);
- }
-
-+static inline bool delay_is_fast(struct delay_c *dc)
-+{
-+ return !!dc->worker;
-+}
-+
-+static void flush_delayed_bios_fast(struct delay_c *dc, bool flush_all)
-+{
-+ struct dm_delay_info *delayed, *next;
-+
-+ mutex_lock(&delayed_bios_lock);
-+ list_for_each_entry_safe(delayed, next, &dc->delayed_bios, list) {
-+ if (flush_all || time_after_eq(jiffies, delayed->expires)) {
-+ struct bio *bio = dm_bio_from_per_bio_data(delayed,
-+ sizeof(struct dm_delay_info));
-+ list_del(&delayed->list);
-+ dm_submit_bio_remap(bio, NULL);
-+ delayed->class->ops--;
-+ }
-+ }
-+ mutex_unlock(&delayed_bios_lock);
-+}
-+
-+static int flush_worker_fn(void *data)
-+{
-+ struct delay_c *dc = data;
-+
-+ while (1) {
-+ flush_delayed_bios_fast(dc, false);
-+ if (unlikely(list_empty(&dc->delayed_bios))) {
-+ set_current_state(TASK_INTERRUPTIBLE);
-+ schedule();
-+ } else
-+ cond_resched();
-+ }
-+
-+ return 0;
-+}
-+
- static void flush_bios(struct bio *bio)
- {
- struct bio *n;
-@@ -77,7 +117,7 @@ static void flush_bios(struct bio *bio)
- }
- }
-
--static struct bio *flush_delayed_bios(struct delay_c *dc, int flush_all)
-+static struct bio *flush_delayed_bios(struct delay_c *dc, bool flush_all)
- {
- struct dm_delay_info *delayed, *next;
- unsigned long next_expires = 0;
-@@ -114,7 +154,10 @@ static void flush_expired_bios(struct work_struct *work)
- struct delay_c *dc;
-
- dc = container_of(work, struct delay_c, flush_expired_bios);
-- flush_bios(flush_delayed_bios(dc, 0));
-+ if (delay_is_fast(dc))
-+ flush_delayed_bios_fast(dc, false);
-+ else
-+ flush_bios(flush_delayed_bios(dc, false));
- }
-
- static void delay_dtr(struct dm_target *ti)
-@@ -130,8 +173,11 @@ static void delay_dtr(struct dm_target *ti)
- dm_put_device(ti, dc->write.dev);
- if (dc->flush.dev)
- dm_put_device(ti, dc->flush.dev);
-+ if (dc->worker)
-+ kthread_stop(dc->worker);
-
-- mutex_destroy(&dc->timer_lock);
-+ if (!delay_is_fast(dc))
-+ mutex_destroy(&dc->timer_lock);
-
- kfree(dc);
- }
-@@ -174,6 +220,7 @@ static int delay_ctr(struct dm_target *ti, unsigned int argc, char **argv)
- {
- struct delay_c *dc;
- int ret;
-+ unsigned int max_delay;
-
- if (argc != 3 && argc != 6 && argc != 9) {
- ti->error = "Requires exactly 3, 6 or 9 arguments";
-@@ -187,16 +234,14 @@ static int delay_ctr(struct dm_target *ti, unsigned int argc, char **argv)
- }
-
- ti->private = dc;
-- timer_setup(&dc->delay_timer, handle_delayed_timer, 0);
-- INIT_WORK(&dc->flush_expired_bios, flush_expired_bios);
- INIT_LIST_HEAD(&dc->delayed_bios);
-- mutex_init(&dc->timer_lock);
- atomic_set(&dc->may_delay, 1);
- dc->argc = argc;
-
- ret = delay_class_ctr(ti, &dc->read, argv);
- if (ret)
- goto bad;
-+ max_delay = dc->read.delay;
-
- if (argc == 3) {
- ret = delay_class_ctr(ti, &dc->write, argv);
-@@ -205,6 +250,8 @@ static int delay_ctr(struct dm_target *ti, unsigned int argc, char **argv)
- ret = delay_class_ctr(ti, &dc->flush, argv);
- if (ret)
- goto bad;
-+ max_delay = max(max_delay, dc->write.delay);
-+ max_delay = max(max_delay, dc->flush.delay);
- goto out;
- }
-
-@@ -215,19 +262,37 @@ static int delay_ctr(struct dm_target *ti, unsigned int argc, char **argv)
- ret = delay_class_ctr(ti, &dc->flush, argv + 3);
- if (ret)
- goto bad;
-+ max_delay = max(max_delay, dc->flush.delay);
- goto out;
- }
-
- ret = delay_class_ctr(ti, &dc->flush, argv + 6);
- if (ret)
- goto bad;
-+ max_delay = max(max_delay, dc->flush.delay);
-
- out:
-- dc->kdelayd_wq = alloc_workqueue("kdelayd", WQ_MEM_RECLAIM, 0);
-- if (!dc->kdelayd_wq) {
-- ret = -EINVAL;
-- DMERR("Couldn't start kdelayd");
-- goto bad;
-+ if (max_delay < 50) {
-+ /*
-+ * In case of small requested delays, use kthread instead of
-+ * timers and workqueue to achieve better latency.
-+ */
-+ dc->worker = kthread_create(&flush_worker_fn, dc,
-+ "dm-delay-flush-worker");
-+ if (IS_ERR(dc->worker)) {
-+ ret = PTR_ERR(dc->worker);
-+ goto bad;
-+ }
-+ } else {
-+ timer_setup(&dc->delay_timer, handle_delayed_timer, 0);
-+ INIT_WORK(&dc->flush_expired_bios, flush_expired_bios);
-+ mutex_init(&dc->timer_lock);
-+ dc->kdelayd_wq = alloc_workqueue("kdelayd", WQ_MEM_RECLAIM, 0);
-+ if (!dc->kdelayd_wq) {
-+ ret = -EINVAL;
-+ DMERR("Couldn't start kdelayd");
-+ goto bad;
-+ }
- }
-
- ti->num_flush_bios = 1;
-@@ -259,7 +324,10 @@ static int delay_bio(struct delay_c *dc, struct delay_class *c, struct bio *bio)
- list_add_tail(&delayed->list, &dc->delayed_bios);
- mutex_unlock(&delayed_bios_lock);
-
-- queue_timeout(dc, expires);
-+ if (delay_is_fast(dc))
-+ wake_up_process(dc->worker);
-+ else
-+ queue_timeout(dc, expires);
-
- return DM_MAPIO_SUBMITTED;
- }
-@@ -269,8 +337,13 @@ static void delay_presuspend(struct dm_target *ti)
- struct delay_c *dc = ti->private;
-
- atomic_set(&dc->may_delay, 0);
-- del_timer_sync(&dc->delay_timer);
-- flush_bios(flush_delayed_bios(dc, 1));
-+
-+ if (delay_is_fast(dc))
-+ flush_delayed_bios_fast(dc, true);
-+ else {
-+ del_timer_sync(&dc->delay_timer);
-+ flush_bios(flush_delayed_bios(dc, true));
-+ }
- }
-
- static void delay_resume(struct dm_target *ti)
-@@ -355,7 +428,7 @@ static int delay_iterate_devices(struct dm_target *ti,
-
- static struct target_type delay_target = {
- .name = "delay",
-- .version = {1, 3, 0},
-+ .version = {1, 4, 0},
- .features = DM_TARGET_PASSES_INTEGRITY,
- .module = THIS_MODULE,
- .ctr = delay_ctr,
---
-2.42.0
-
cifs-account-for-primary-channel-in-the-interface-li.patch
cifs-fix-leak-of-iface-for-primary-channel.patch
mips-kvm-fix-a-build-warning-about-variable-set-but-.patch
-dm-delay-for-short-delays-use-kthread-instead-of-tim.patch
dm-delay-fix-a-race-between-delay_presuspend-and-del.patch
media-camss-split-power-domain-management.patch
media-camss-convert-to-platform-remove-callback-retu.patch
+++ /dev/null
-From 976fd593415e170a8ed5db68683b280d5876982d Mon Sep 17 00:00:00 2001
-From: Sasha Levin <sashal@kernel.org>
-Date: Fri, 20 Oct 2023 12:46:05 +0100
-Subject: dm delay: for short delays, use kthread instead of timers and wq
-
-From: Christian Loehle <christian.loehle@arm.com>
-
-[ Upstream commit 70bbeb29fab09d6ea6cfe64109db60a97d84d739 ]
-
-DM delay's current design of using timers and wq to realize the delays
-is insufficient for delays below ~50ms.
-
-This commit enhances the design to use a kthread to flush the expired
-delays, trading some CPU time (in some cases) for better delay
-accuracy and delays closer to what the user requested for smaller
-delays. The new design is chosen as long as all the delays are below
-50ms.
-
-Since bios can't be completed in interrupt context using a kthread
-is probably the most reasonable way to approach this.
-
-Testing with
-echo "0 2097152 zero" | dmsetup create dm-zeros
-for i in $(seq 0 20);
-do
- echo "0 2097152 delay /dev/mapper/dm-zeros 0 $i" | dmsetup create dm-delay-${i}ms;
-done
-
-Some performance numbers for comparison, on beaglebone black (single
-core) CONFIG_HZ_1000=y:
-
-fio --name=1msread --rw=randread --bs=4k --runtime=60 --time_based \
- --filename=/dev/mapper/dm-delay-1ms
-Theoretical maximum: 1000 IOPS
-Previous: 250 IOPS
-Kthread: 500 IOPS
-
-fio --name=10msread --rw=randread --bs=4k --runtime=60 --time_based \
- --filename=/dev/mapper/dm-delay-10ms
-Theoretical maximum: 100 IOPS
-Previous: 45 IOPS
-Kthread: 50 IOPS
-
-fio --name=1mswrite --rw=randwrite --direct=1 --bs=4k --runtime=60 \
- --time_based --filename=/dev/mapper/dm-delay-1ms
-Theoretical maximum: 1000 IOPS
-Previous: 498 IOPS
-Kthread: 1000 IOPS
-
-fio --name=10mswrite --rw=randwrite --direct=1 --bs=4k --runtime=60 \
- --time_based --filename=/dev/mapper/dm-delay-10ms
-Theoretical maximum: 100 IOPS
-Previous: 90 IOPS
-Kthread: 100 IOPS
-
-(This one is just to prove the new design isn't impacting throughput,
-not really about delays):
-fio --name=10mswriteasync --rw=randwrite --direct=1 --bs=4k \
- --runtime=60 --time_based --filename=/dev/mapper/dm-delay-10ms \
- --numjobs=32 --iodepth=64 --ioengine=libaio --group_reporting
-Previous: 13.3k IOPS
-Kthread: 13.3k IOPS
-
-Signed-off-by: Christian Loehle <christian.loehle@arm.com>
-[Harshit: kthread_create error handling fix in delay_ctr]
-Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
-Signed-off-by: Mike Snitzer <snitzer@kernel.org>
-Stable-dep-of: 6fc45b6ed921 ("dm-delay: fix a race between delay_presuspend and delay_bio")
-Signed-off-by: Sasha Levin <sashal@kernel.org>
----
- drivers/md/dm-delay.c | 103 ++++++++++++++++++++++++++++++++++++------
- 1 file changed, 88 insertions(+), 15 deletions(-)
-
-diff --git a/drivers/md/dm-delay.c b/drivers/md/dm-delay.c
-index 7433525e59856..efd510984e259 100644
---- a/drivers/md/dm-delay.c
-+++ b/drivers/md/dm-delay.c
-@@ -13,6 +13,7 @@
- #include <linux/blkdev.h>
- #include <linux/bio.h>
- #include <linux/slab.h>
-+#include <linux/kthread.h>
-
- #include <linux/device-mapper.h>
-
-@@ -31,6 +32,7 @@ struct delay_c {
- struct workqueue_struct *kdelayd_wq;
- struct work_struct flush_expired_bios;
- struct list_head delayed_bios;
-+ struct task_struct *worker;
- atomic_t may_delay;
-
- struct delay_class read;
-@@ -66,6 +68,44 @@ static void queue_timeout(struct delay_c *dc, unsigned long expires)
- mutex_unlock(&dc->timer_lock);
- }
-
-+static inline bool delay_is_fast(struct delay_c *dc)
-+{
-+ return !!dc->worker;
-+}
-+
-+static void flush_delayed_bios_fast(struct delay_c *dc, bool flush_all)
-+{
-+ struct dm_delay_info *delayed, *next;
-+
-+ mutex_lock(&delayed_bios_lock);
-+ list_for_each_entry_safe(delayed, next, &dc->delayed_bios, list) {
-+ if (flush_all || time_after_eq(jiffies, delayed->expires)) {
-+ struct bio *bio = dm_bio_from_per_bio_data(delayed,
-+ sizeof(struct dm_delay_info));
-+ list_del(&delayed->list);
-+ dm_submit_bio_remap(bio, NULL);
-+ delayed->class->ops--;
-+ }
-+ }
-+ mutex_unlock(&delayed_bios_lock);
-+}
-+
-+static int flush_worker_fn(void *data)
-+{
-+ struct delay_c *dc = data;
-+
-+ while (1) {
-+ flush_delayed_bios_fast(dc, false);
-+ if (unlikely(list_empty(&dc->delayed_bios))) {
-+ set_current_state(TASK_INTERRUPTIBLE);
-+ schedule();
-+ } else
-+ cond_resched();
-+ }
-+
-+ return 0;
-+}
-+
- static void flush_bios(struct bio *bio)
- {
- struct bio *n;
-@@ -78,7 +118,7 @@ static void flush_bios(struct bio *bio)
- }
- }
-
--static struct bio *flush_delayed_bios(struct delay_c *dc, int flush_all)
-+static struct bio *flush_delayed_bios(struct delay_c *dc, bool flush_all)
- {
- struct dm_delay_info *delayed, *next;
- unsigned long next_expires = 0;
-@@ -115,7 +155,10 @@ static void flush_expired_bios(struct work_struct *work)
- struct delay_c *dc;
-
- dc = container_of(work, struct delay_c, flush_expired_bios);
-- flush_bios(flush_delayed_bios(dc, 0));
-+ if (delay_is_fast(dc))
-+ flush_delayed_bios_fast(dc, false);
-+ else
-+ flush_bios(flush_delayed_bios(dc, false));
- }
-
- static void delay_dtr(struct dm_target *ti)
-@@ -131,8 +174,11 @@ static void delay_dtr(struct dm_target *ti)
- dm_put_device(ti, dc->write.dev);
- if (dc->flush.dev)
- dm_put_device(ti, dc->flush.dev);
-+ if (dc->worker)
-+ kthread_stop(dc->worker);
-
-- mutex_destroy(&dc->timer_lock);
-+ if (!delay_is_fast(dc))
-+ mutex_destroy(&dc->timer_lock);
-
- kfree(dc);
- }
-@@ -175,6 +221,7 @@ static int delay_ctr(struct dm_target *ti, unsigned int argc, char **argv)
- {
- struct delay_c *dc;
- int ret;
-+ unsigned int max_delay;
-
- if (argc != 3 && argc != 6 && argc != 9) {
- ti->error = "Requires exactly 3, 6 or 9 arguments";
-@@ -188,16 +235,14 @@ static int delay_ctr(struct dm_target *ti, unsigned int argc, char **argv)
- }
-
- ti->private = dc;
-- timer_setup(&dc->delay_timer, handle_delayed_timer, 0);
-- INIT_WORK(&dc->flush_expired_bios, flush_expired_bios);
- INIT_LIST_HEAD(&dc->delayed_bios);
-- mutex_init(&dc->timer_lock);
- atomic_set(&dc->may_delay, 1);
- dc->argc = argc;
-
- ret = delay_class_ctr(ti, &dc->read, argv);
- if (ret)
- goto bad;
-+ max_delay = dc->read.delay;
-
- if (argc == 3) {
- ret = delay_class_ctr(ti, &dc->write, argv);
-@@ -206,6 +251,8 @@ static int delay_ctr(struct dm_target *ti, unsigned int argc, char **argv)
- ret = delay_class_ctr(ti, &dc->flush, argv);
- if (ret)
- goto bad;
-+ max_delay = max(max_delay, dc->write.delay);
-+ max_delay = max(max_delay, dc->flush.delay);
- goto out;
- }
-
-@@ -216,19 +263,37 @@ static int delay_ctr(struct dm_target *ti, unsigned int argc, char **argv)
- ret = delay_class_ctr(ti, &dc->flush, argv + 3);
- if (ret)
- goto bad;
-+ max_delay = max(max_delay, dc->flush.delay);
- goto out;
- }
-
- ret = delay_class_ctr(ti, &dc->flush, argv + 6);
- if (ret)
- goto bad;
-+ max_delay = max(max_delay, dc->flush.delay);
-
- out:
-- dc->kdelayd_wq = alloc_workqueue("kdelayd", WQ_MEM_RECLAIM, 0);
-- if (!dc->kdelayd_wq) {
-- ret = -EINVAL;
-- DMERR("Couldn't start kdelayd");
-- goto bad;
-+ if (max_delay < 50) {
-+ /*
-+ * In case of small requested delays, use kthread instead of
-+ * timers and workqueue to achieve better latency.
-+ */
-+ dc->worker = kthread_create(&flush_worker_fn, dc,
-+ "dm-delay-flush-worker");
-+ if (IS_ERR(dc->worker)) {
-+ ret = PTR_ERR(dc->worker);
-+ goto bad;
-+ }
-+ } else {
-+ timer_setup(&dc->delay_timer, handle_delayed_timer, 0);
-+ INIT_WORK(&dc->flush_expired_bios, flush_expired_bios);
-+ mutex_init(&dc->timer_lock);
-+ dc->kdelayd_wq = alloc_workqueue("kdelayd", WQ_MEM_RECLAIM, 0);
-+ if (!dc->kdelayd_wq) {
-+ ret = -EINVAL;
-+ DMERR("Couldn't start kdelayd");
-+ goto bad;
-+ }
- }
-
- ti->num_flush_bios = 1;
-@@ -260,7 +325,10 @@ static int delay_bio(struct delay_c *dc, struct delay_class *c, struct bio *bio)
- list_add_tail(&delayed->list, &dc->delayed_bios);
- mutex_unlock(&delayed_bios_lock);
-
-- queue_timeout(dc, expires);
-+ if (delay_is_fast(dc))
-+ wake_up_process(dc->worker);
-+ else
-+ queue_timeout(dc, expires);
-
- return DM_MAPIO_SUBMITTED;
- }
-@@ -270,8 +338,13 @@ static void delay_presuspend(struct dm_target *ti)
- struct delay_c *dc = ti->private;
-
- atomic_set(&dc->may_delay, 0);
-- del_timer_sync(&dc->delay_timer);
-- flush_bios(flush_delayed_bios(dc, 1));
-+
-+ if (delay_is_fast(dc))
-+ flush_delayed_bios_fast(dc, true);
-+ else {
-+ del_timer_sync(&dc->delay_timer);
-+ flush_bios(flush_delayed_bios(dc, true));
-+ }
- }
-
- static void delay_resume(struct dm_target *ti)
-@@ -356,7 +429,7 @@ static int delay_iterate_devices(struct dm_target *ti,
-
- static struct target_type delay_target = {
- .name = "delay",
-- .version = {1, 3, 0},
-+ .version = {1, 4, 0},
- .features = DM_TARGET_PASSES_INTEGRITY,
- .module = THIS_MODULE,
- .ctr = delay_ctr,
---
-2.42.0
-
cifs-fix-leak-of-iface-for-primary-channel.patch
alsa-hda-asus-um5302la-added-quirks-for-cs35l41-1043.patch
alsa-hda-realtek-add-quirks-for-asus-2024-zenbooks.patch
-dm-delay-for-short-delays-use-kthread-instead-of-tim.patch
dm-delay-fix-a-race-between-delay_presuspend-and-del.patch
projects / thirdparty / kernel / stable-queue.git / commitdiff
