+++ /dev/null
-From 8a796565cec3601071cbbd27d6304e202019d014 Mon Sep 17 00:00:00 2001
-From: Andres Freund <andres@anarazel.de>
-Date: Fri, 7 Jul 2023 09:20:07 -0700
-Subject: io_uring: Use io_schedule* in cqring wait
-
-From: Andres Freund <andres@anarazel.de>
-
-commit 8a796565cec3601071cbbd27d6304e202019d014 upstream.
-
-I observed poor performance of io_uring compared to synchronous IO. That
-turns out to be caused by deeper CPU idle states entered with io_uring,
-due to io_uring using plain schedule(), whereas synchronous IO uses
-io_schedule().
-
-The losses due to this are substantial. On my cascade lake workstation,
-t/io_uring from the fio repository e.g. yields regressions between 20%
-and 40% with the following command:
-./t/io_uring -r 5 -X0 -d 1 -s 1 -c 1 -p 0 -S$use_sync -R 0 /mnt/t2/fio/write.0.0
-
-This is repeatable with different filesystems, using raw block devices
-and using different block devices.
-
-Use io_schedule_prepare() / io_schedule_finish() in
-io_cqring_wait_schedule() to address the difference.
-
-After that using io_uring is on par or surpassing synchronous IO (using
-registered files etc makes it reliably win, but arguably is a less fair
-comparison).
-
-There are other calls to schedule() in io_uring/, but none immediately
-jump out to be similarly situated, so I did not touch them. Similarly,
-it's possible that mutex_lock_io() should be used, but it's not clear if
-there are cases where that matters.
-
-Cc: stable@vger.kernel.org # 5.10+
-Cc: Pavel Begunkov <asml.silence@gmail.com>
-Cc: io-uring@vger.kernel.org
-Cc: linux-kernel@vger.kernel.org
-Signed-off-by: Andres Freund <andres@anarazel.de>
-Link: https://lore.kernel.org/r/20230707162007.194068-1-andres@anarazel.de
-[axboe: minor style fixup]
-Signed-off-by: Jens Axboe <axboe@kernel.dk>
-Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
----
- io_uring/io_uring.c | 14 +++++++++++---
- 1 file changed, 11 insertions(+), 3 deletions(-)
-
---- a/io_uring/io_uring.c
-+++ b/io_uring/io_uring.c
-@@ -7625,7 +7625,7 @@ static inline int io_cqring_wait_schedul
- struct io_wait_queue *iowq,
- ktime_t *timeout)
- {
-- int ret;
-+ int token, ret;
-
- /* make sure we run task_work before checking for signals */
- ret = io_run_task_work_sig();
-@@ -7635,9 +7635,17 @@ static inline int io_cqring_wait_schedul
- if (test_bit(0, &ctx->check_cq_overflow))
- return 1;
-
-+ /*
-+ * Use io_schedule_prepare/finish, so cpufreq can take into account
-+ * that the task is waiting for IO - turns out to be important for low
-+ * QD IO.
-+ */
-+ token = io_schedule_prepare();
-+ ret = 0;
- if (!schedule_hrtimeout(timeout, HRTIMER_MODE_ABS))
-- return -ETIME;
-- return 1;
-+ ret = -ETIME;
-+ io_schedule_finish(token);
-+ return ret;
- }
-
- /*
selftests-bpf-add-verifier-test-for-ptr_to_mem-spill.patch
block-add-overflow-checks-for-amiga-partition-support.patch
mips-dts-ci20-raise-vddcore-voltage-to-1.125-volts.patch
-io_uring-use-io_schedule-in-cqring-wait.patch
sh-pgtable-3level-fix-cast-to-pointer-from-integer-of-different-size.patch
netfilter-nf_tables-use-net_generic-infra-for-transaction-data.patch
netfilter-nf_tables-add-rescheduling-points-during-loop-detection-walks.patch
+++ /dev/null
-From 8a796565cec3601071cbbd27d6304e202019d014 Mon Sep 17 00:00:00 2001
-From: Andres Freund <andres@anarazel.de>
-Date: Fri, 7 Jul 2023 09:20:07 -0700
-Subject: io_uring: Use io_schedule* in cqring wait
-
-From: Andres Freund <andres@anarazel.de>
-
-commit 8a796565cec3601071cbbd27d6304e202019d014 upstream.
-
-I observed poor performance of io_uring compared to synchronous IO. That
-turns out to be caused by deeper CPU idle states entered with io_uring,
-due to io_uring using plain schedule(), whereas synchronous IO uses
-io_schedule().
-
-The losses due to this are substantial. On my cascade lake workstation,
-t/io_uring from the fio repository e.g. yields regressions between 20%
-and 40% with the following command:
-./t/io_uring -r 5 -X0 -d 1 -s 1 -c 1 -p 0 -S$use_sync -R 0 /mnt/t2/fio/write.0.0
-
-This is repeatable with different filesystems, using raw block devices
-and using different block devices.
-
-Use io_schedule_prepare() / io_schedule_finish() in
-io_cqring_wait_schedule() to address the difference.
-
-After that using io_uring is on par or surpassing synchronous IO (using
-registered files etc makes it reliably win, but arguably is a less fair
-comparison).
-
-There are other calls to schedule() in io_uring/, but none immediately
-jump out to be similarly situated, so I did not touch them. Similarly,
-it's possible that mutex_lock_io() should be used, but it's not clear if
-there are cases where that matters.
-
-Cc: stable@vger.kernel.org # 5.10+
-Cc: Pavel Begunkov <asml.silence@gmail.com>
-Cc: io-uring@vger.kernel.org
-Cc: linux-kernel@vger.kernel.org
-Signed-off-by: Andres Freund <andres@anarazel.de>
-Link: https://lore.kernel.org/r/20230707162007.194068-1-andres@anarazel.de
-[axboe: minor style fixup]
-Signed-off-by: Jens Axboe <axboe@kernel.dk>
-Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
----
- io_uring/io_uring.c | 14 +++++++++++---
- 1 file changed, 11 insertions(+), 3 deletions(-)
-
---- a/io_uring/io_uring.c
-+++ b/io_uring/io_uring.c
-@@ -7796,7 +7796,7 @@ static inline int io_cqring_wait_schedul
- struct io_wait_queue *iowq,
- ktime_t *timeout)
- {
-- int ret;
-+ int token, ret;
-
- /* make sure we run task_work before checking for signals */
- ret = io_run_task_work_sig();
-@@ -7806,9 +7806,17 @@ static inline int io_cqring_wait_schedul
- if (test_bit(0, &ctx->check_cq_overflow))
- return 1;
-
-+ /*
-+ * Use io_schedule_prepare/finish, so cpufreq can take into account
-+ * that the task is waiting for IO - turns out to be important for low
-+ * QD IO.
-+ */
-+ token = io_schedule_prepare();
-+ ret = 0;
- if (!schedule_hrtimeout(timeout, HRTIMER_MODE_ABS))
-- return -ETIME;
-- return 1;
-+ ret = -ETIME;
-+ io_schedule_finish(token);
-+ return ret;
- }
-
- /*
fanotify-disallow-mount-sb-marks-on-kernel-internal-pseudo-fs.patch
netfilter-nf_tables-unbind-non-anonymous-set-if-rule-construction-fails.patch
mips-dts-ci20-raise-vddcore-voltage-to-1.125-volts.patch
-io_uring-use-io_schedule-in-cqring-wait.patch
netfilter-conntrack-avoid-nf_ct_helper_hash-uses-after-free.patch
netfilter-nf_tables-do-not-ignore-genmask-when-looking-up-chain-by-id.patch
netfilter-nf_tables-prevent-oob-access-in-nft_byteorder_eval.patch
+++ /dev/null
-From 8a796565cec3601071cbbd27d6304e202019d014 Mon Sep 17 00:00:00 2001
-From: Andres Freund <andres@anarazel.de>
-Date: Fri, 7 Jul 2023 09:20:07 -0700
-Subject: io_uring: Use io_schedule* in cqring wait
-
-From: Andres Freund <andres@anarazel.de>
-
-commit 8a796565cec3601071cbbd27d6304e202019d014 upstream.
-
-I observed poor performance of io_uring compared to synchronous IO. That
-turns out to be caused by deeper CPU idle states entered with io_uring,
-due to io_uring using plain schedule(), whereas synchronous IO uses
-io_schedule().
-
-The losses due to this are substantial. On my cascade lake workstation,
-t/io_uring from the fio repository e.g. yields regressions between 20%
-and 40% with the following command:
-./t/io_uring -r 5 -X0 -d 1 -s 1 -c 1 -p 0 -S$use_sync -R 0 /mnt/t2/fio/write.0.0
-
-This is repeatable with different filesystems, using raw block devices
-and using different block devices.
-
-Use io_schedule_prepare() / io_schedule_finish() in
-io_cqring_wait_schedule() to address the difference.
-
-After that using io_uring is on par or surpassing synchronous IO (using
-registered files etc makes it reliably win, but arguably is a less fair
-comparison).
-
-There are other calls to schedule() in io_uring/, but none immediately
-jump out to be similarly situated, so I did not touch them. Similarly,
-it's possible that mutex_lock_io() should be used, but it's not clear if
-there are cases where that matters.
-
-Cc: stable@vger.kernel.org # 5.10+
-Cc: Pavel Begunkov <asml.silence@gmail.com>
-Cc: io-uring@vger.kernel.org
-Cc: linux-kernel@vger.kernel.org
-Signed-off-by: Andres Freund <andres@anarazel.de>
-Link: https://lore.kernel.org/r/20230707162007.194068-1-andres@anarazel.de
-[axboe: minor style fixup]
-Signed-off-by: Jens Axboe <axboe@kernel.dk>
-Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
----
- io_uring/io_uring.c | 15 ++++++++++++---
- 1 file changed, 12 insertions(+), 3 deletions(-)
-
---- a/io_uring/io_uring.c
-+++ b/io_uring/io_uring.c
-@@ -2346,7 +2346,7 @@ static inline int io_cqring_wait_schedul
- struct io_wait_queue *iowq,
- ktime_t *timeout)
- {
-- int ret;
-+ int token, ret;
- unsigned long check_cq;
-
- /* make sure we run task_work before checking for signals */
-@@ -2362,9 +2362,18 @@ static inline int io_cqring_wait_schedul
- if (check_cq & BIT(IO_CHECK_CQ_DROPPED_BIT))
- return -EBADR;
- }
-+
-+ /*
-+ * Use io_schedule_prepare/finish, so cpufreq can take into account
-+ * that the task is waiting for IO - turns out to be important for low
-+ * QD IO.
-+ */
-+ token = io_schedule_prepare();
-+ ret = 0;
- if (!schedule_hrtimeout(timeout, HRTIMER_MODE_ABS))
-- return -ETIME;
-- return 1;
-+ ret = -ETIME;
-+ io_schedule_finish(token);
-+ return ret;
- }
-
- /*
blk-cgroup-flush-stats-before-releasing-blkcg_gq.patch
mips-dts-ci20-raise-vddcore-voltage-to-1.125-volts.patch
block-make-sure-local-irq-is-disabled-when-calling-__blkcg_rstat_flush.patch
-io_uring-use-io_schedule-in-cqring-wait.patch
netfilter-conntrack-avoid-nf_ct_helper_hash-uses-after-free.patch
netfilter-nf_tables-do-not-ignore-genmask-when-looking-up-chain-by-id.patch
netfilter-nf_tables-prevent-oob-access-in-nft_byteorder_eval.patch
projects / thirdparty / kernel / stable-queue.git / commitdiff
