[PATCH v4 0/9] Misc fixes for throttle

[PATCH v4 0/9] Misc fixes for throttle

[zhenwei pi]

v3 -> v4:
- Hanna pointed out that 'throttle type' is not clear enough,
  'throttle direction' would be better in the v3.
  Use 'ThrottleDirection' instead, also rename 'ThrottleType throttle' to 'ThrottleDirection direction'.

- For patch 'throttle: support read-only and write-only', reduce codes by:
for (dir = THROTTLE_READ; dir < THROTTLE_MAX; dir++) {
    ...
}

- Add commit message for the removed 'FIXME' tag.

- Append 'throttle: use THROTTLE_MAX/ARRAY_SIZE for hard code'
- Append 'fsdev: Use ThrottleDirection instread of bool is_write'
- Append 'block/throttle-groups: Use ThrottleDirection instread of bool is_write'

Finally, 'bool is_write' has been fully removed from throttle related codes,
'type foo[2]' becomes 'type foo[THROTTLE_MAX]'.

v2 -> v3:
- patch 1 -> patch 5 are already reviewed by Alberto
- append patch 6: throttle: use enum ThrottleType instead of bool is_write

v1 -> v2:
- rename 'ThrottleTimerType' to 'ThrottleType'
- add assertion to throttle_schedule_timer

v1:
- introduce enum ThrottleTimerType instead of timers[0], timer[1]...
- support read-only and write-only for throttle
- adapt related test codes
- cryptodev uses a write-only throttle timer

Zhenwei Pi (9):
  throttle: introduce enum ThrottleDirection
  test-throttle: use enum ThrottleDirection
  throttle: support read-only and write-only
  test-throttle: test read only and write only
  cryptodev: use NULL throttle timer cb for read direction
  throttle: use enum ThrottleDirection instead of bool is_write
  throttle: use THROTTLE_MAX/ARRAY_SIZE for hard code
  fsdev: Use ThrottleDirection instread of bool is_write
  block/throttle-groups: Use ThrottleDirection instread of bool is_write

 backends/cryptodev.c            |  12 ++--
 block/throttle-groups.c         | 107 ++++++++++++++++----------------
 block/throttle.c                |   8 +--
 fsdev/qemu-fsdev-throttle.c     |  18 +++---
 fsdev/qemu-fsdev-throttle.h     |   4 +-
 hw/9pfs/cofile.c                |   4 +-
 include/block/throttle-groups.h |   6 +-
 include/qemu/throttle.h         |  16 +++--
 tests/unit/test-throttle.c      |  76 +++++++++++++++++++++--
 util/throttle.c                 |  84 +++++++++++++++----------
 10 files changed, 216 insertions(+), 119 deletions(-)

-- 
2.34.1

[PATCH v4 1/9] throttle: introduce enum ThrottleDirection

[zhenwei pi]

Use enum ThrottleDirection instead of number index.

Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
---
 include/qemu/throttle.h | 11 ++++++++---
 util/throttle.c         | 16 +++++++++-------
 2 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/include/qemu/throttle.h b/include/qemu/throttle.h
index 05f6346137..9ca5ab8197 100644
--- a/include/qemu/throttle.h
+++ b/include/qemu/throttle.h
@@ -99,13 +99,18 @@ typedef struct ThrottleState {
     int64_t previous_leak;    /* timestamp of the last leak done */
 } ThrottleState;
 
+typedef enum {
+    THROTTLE_READ = 0,
+    THROTTLE_WRITE,
+    THROTTLE_MAX
+} ThrottleDirection;
+
 typedef struct ThrottleTimers {
-    QEMUTimer *timers[2];     /* timers used to do the throttling */
+    QEMUTimer *timers[THROTTLE_MAX];    /* timers used to do the throttling */
     QEMUClockType clock_type; /* the clock used */
 
     /* Callbacks */
-    QEMUTimerCB *read_timer_cb;
-    QEMUTimerCB *write_timer_cb;
+    QEMUTimerCB *timer_cb[THROTTLE_MAX];
     void *timer_opaque;
 } ThrottleTimers;
 
diff --git a/util/throttle.c b/util/throttle.c
index 81f247a8d1..5642e61763 100644
--- a/util/throttle.c
+++ b/util/throttle.c
@@ -199,10 +199,12 @@ static bool throttle_compute_timer(ThrottleState *ts,
 void throttle_timers_attach_aio_context(ThrottleTimers *tt,
                                         AioContext *new_context)
 {
-    tt->timers[0] = aio_timer_new(new_context, tt->clock_type, SCALE_NS,
-                                  tt->read_timer_cb, tt->timer_opaque);
-    tt->timers[1] = aio_timer_new(new_context, tt->clock_type, SCALE_NS,
-                                  tt->write_timer_cb, tt->timer_opaque);
+    tt->timers[THROTTLE_READ] =
+        aio_timer_new(new_context, tt->clock_type, SCALE_NS,
+                      tt->timer_cb[THROTTLE_READ], tt->timer_opaque);
+    tt->timers[THROTTLE_WRITE] =
+        aio_timer_new(new_context, tt->clock_type, SCALE_NS,
+                      tt->timer_cb[THROTTLE_WRITE], tt->timer_opaque);
 }
 
 /*
@@ -236,8 +238,8 @@ void throttle_timers_init(ThrottleTimers *tt,
     memset(tt, 0, sizeof(ThrottleTimers));
 
     tt->clock_type = clock_type;
-    tt->read_timer_cb = read_timer_cb;
-    tt->write_timer_cb = write_timer_cb;
+    tt->timer_cb[THROTTLE_READ] = read_timer_cb;
+    tt->timer_cb[THROTTLE_WRITE] = write_timer_cb;
     tt->timer_opaque = timer_opaque;
     throttle_timers_attach_aio_context(tt, aio_context);
 }
@@ -256,7 +258,7 @@ void throttle_timers_detach_aio_context(ThrottleTimers *tt)
 {
     int i;
 
-    for (i = 0; i < 2; i++) {
+    for (i = 0; i < THROTTLE_MAX; i++) {
         throttle_timer_destroy(&tt->timers[i]);
     }
 }
-- 
2.34.1

[PATCH v4 2/9] test-throttle: use enum ThrottleDirection

[zhenwei pi]

Use enum ThrottleDirection instead in the throttle test codes.

Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
---
 tests/unit/test-throttle.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tests/unit/test-throttle.c b/tests/unit/test-throttle.c
index 7adb5e6652..a60b5fe22e 100644
--- a/tests/unit/test-throttle.c
+++ b/tests/unit/test-throttle.c
@@ -169,8 +169,8 @@ static void test_init(void)
 
     /* check initialized fields */
     g_assert(tt->clock_type == QEMU_CLOCK_VIRTUAL);
-    g_assert(tt->timers[0]);
-    g_assert(tt->timers[1]);
+    g_assert(tt->timers[THROTTLE_READ]);
+    g_assert(tt->timers[THROTTLE_WRITE]);
 
     /* check other fields where cleared */
     g_assert(!ts.previous_leak);
@@ -191,7 +191,7 @@ static void test_destroy(void)
     throttle_timers_init(tt, ctx, QEMU_CLOCK_VIRTUAL,
                          read_timer_cb, write_timer_cb, &ts);
     throttle_timers_destroy(tt);
-    for (i = 0; i < 2; i++) {
+    for (i = 0; i < THROTTLE_MAX; i++) {
         g_assert(!tt->timers[i]);
     }
 }
-- 
2.34.1

[PATCH v4 3/9] throttle: support read-only and write-only

[zhenwei pi]

Only one direction is necessary in several scenarios:
- a read-only disk
- operations on a device are considered as *write* only. For example,
  encrypt/decrypt/sign/verify operations on a cryptodev use a single
  *write* timer(read timer callback is defined, but never invoked).

Allow a single direction in throttle, this reduces memory, and uplayer
does not need a dummy callback any more.

Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
---
 util/throttle.c | 42 ++++++++++++++++++++++++++++--------------
 1 file changed, 28 insertions(+), 14 deletions(-)

diff --git a/util/throttle.c b/util/throttle.c
index 5642e61763..0439028d21 100644
--- a/util/throttle.c
+++ b/util/throttle.c
@@ -199,12 +199,15 @@ static bool throttle_compute_timer(ThrottleState *ts,
 void throttle_timers_attach_aio_context(ThrottleTimers *tt,
                                         AioContext *new_context)
 {
-    tt->timers[THROTTLE_READ] =
-        aio_timer_new(new_context, tt->clock_type, SCALE_NS,
-                      tt->timer_cb[THROTTLE_READ], tt->timer_opaque);
-    tt->timers[THROTTLE_WRITE] =
-        aio_timer_new(new_context, tt->clock_type, SCALE_NS,
-                      tt->timer_cb[THROTTLE_WRITE], tt->timer_opaque);
+    ThrottleDirection dir;
+
+    for (dir = THROTTLE_READ; dir < THROTTLE_MAX; dir++) {
+        if (tt->timer_cb[dir]) {
+            tt->timers[dir] =
+                aio_timer_new(new_context, tt->clock_type, SCALE_NS,
+                              tt->timer_cb[dir], tt->timer_opaque);
+        }
+    }
 }
 
 /*
@@ -235,6 +238,7 @@ void throttle_timers_init(ThrottleTimers *tt,
                           QEMUTimerCB *write_timer_cb,
                           void *timer_opaque)
 {
+    assert(read_timer_cb || write_timer_cb);
     memset(tt, 0, sizeof(ThrottleTimers));
 
     tt->clock_type = clock_type;
@@ -247,7 +251,9 @@ void throttle_timers_init(ThrottleTimers *tt,
 /* destroy a timer */
 static void throttle_timer_destroy(QEMUTimer **timer)
 {
-    assert(*timer != NULL);
+    if (*timer == NULL) {
+        return;
+    }
 
     timer_free(*timer);
     *timer = NULL;
@@ -256,10 +262,10 @@ static void throttle_timer_destroy(QEMUTimer **timer)
 /* Remove timers from event loop */
 void throttle_timers_detach_aio_context(ThrottleTimers *tt)
 {
-    int i;
+    ThrottleDirection dir;
 
-    for (i = 0; i < THROTTLE_MAX; i++) {
-        throttle_timer_destroy(&tt->timers[i]);
+    for (dir = THROTTLE_READ; dir < THROTTLE_MAX; dir++) {
+        throttle_timer_destroy(&tt->timers[dir]);
     }
 }
 
@@ -272,8 +278,12 @@ void throttle_timers_destroy(ThrottleTimers *tt)
 /* is any throttling timer configured */
 bool throttle_timers_are_initialized(ThrottleTimers *tt)
 {
-    if (tt->timers[0]) {
-        return true;
+    ThrottleDirection dir;
+
+    for (dir = THROTTLE_READ; dir < THROTTLE_MAX; dir++) {
+        if (tt->timers[dir]) {
+            return true;
+        }
     }
 
     return false;
@@ -424,8 +434,12 @@ bool throttle_schedule_timer(ThrottleState *ts,
 {
     int64_t now = qemu_clock_get_ns(tt->clock_type);
     int64_t next_timestamp;
+    QEMUTimer *timer;
     bool must_wait;
 
+    timer = is_write ? tt->timers[THROTTLE_WRITE] : tt->timers[THROTTLE_READ];
+    assert(timer);
+
     must_wait = throttle_compute_timer(ts,
                                        is_write,
                                        now,
@@ -437,12 +451,12 @@ bool throttle_schedule_timer(ThrottleState *ts,
     }
 
     /* request throttled and timer pending -> do nothing */
-    if (timer_pending(tt->timers[is_write])) {
+    if (timer_pending(timer)) {
         return true;
     }
 
     /* request throttled and timer not pending -> arm timer */
-    timer_mod(tt->timers[is_write], next_timestamp);
+    timer_mod(timer, next_timestamp);
     return true;
 }
 
-- 
2.34.1

[PATCH v4 4/9] test-throttle: test read only and write only

[zhenwei pi]

Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
---
 tests/unit/test-throttle.c | 66 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 66 insertions(+)

diff --git a/tests/unit/test-throttle.c b/tests/unit/test-throttle.c
index a60b5fe22e..5547837a58 100644
--- a/tests/unit/test-throttle.c
+++ b/tests/unit/test-throttle.c
@@ -184,6 +184,70 @@ static void test_init(void)
     throttle_timers_destroy(tt);
 }
 
+static void test_init_readonly(void)
+{
+    int i;
+
+    tt = &tgm.throttle_timers;
+
+    /* fill the structures with crap */
+    memset(&ts, 1, sizeof(ts));
+    memset(tt, 1, sizeof(*tt));
+
+    /* init structures */
+    throttle_init(&ts);
+    throttle_timers_init(tt, ctx, QEMU_CLOCK_VIRTUAL,
+                         read_timer_cb, NULL, &ts);
+
+    /* check initialized fields */
+    g_assert(tt->clock_type == QEMU_CLOCK_VIRTUAL);
+    g_assert(tt->timers[THROTTLE_READ]);
+    g_assert(!tt->timers[THROTTLE_WRITE]);
+
+    /* check other fields where cleared */
+    g_assert(!ts.previous_leak);
+    g_assert(!ts.cfg.op_size);
+    for (i = 0; i < BUCKETS_COUNT; i++) {
+        g_assert(!ts.cfg.buckets[i].avg);
+        g_assert(!ts.cfg.buckets[i].max);
+        g_assert(!ts.cfg.buckets[i].level);
+    }
+
+    throttle_timers_destroy(tt);
+}
+
+static void test_init_writeonly(void)
+{
+    int i;
+
+    tt = &tgm.throttle_timers;
+
+    /* fill the structures with crap */
+    memset(&ts, 1, sizeof(ts));
+    memset(tt, 1, sizeof(*tt));
+
+    /* init structures */
+    throttle_init(&ts);
+    throttle_timers_init(tt, ctx, QEMU_CLOCK_VIRTUAL,
+                         NULL, write_timer_cb, &ts);
+
+    /* check initialized fields */
+    g_assert(tt->clock_type == QEMU_CLOCK_VIRTUAL);
+    g_assert(!tt->timers[THROTTLE_READ]);
+    g_assert(tt->timers[THROTTLE_WRITE]);
+
+    /* check other fields where cleared */
+    g_assert(!ts.previous_leak);
+    g_assert(!ts.cfg.op_size);
+    for (i = 0; i < BUCKETS_COUNT; i++) {
+        g_assert(!ts.cfg.buckets[i].avg);
+        g_assert(!ts.cfg.buckets[i].max);
+        g_assert(!ts.cfg.buckets[i].level);
+    }
+
+    throttle_timers_destroy(tt);
+}
+
 static void test_destroy(void)
 {
     int i;
@@ -752,6 +816,8 @@ int main(int argc, char **argv)
     g_test_add_func("/throttle/leak_bucket",        test_leak_bucket);
     g_test_add_func("/throttle/compute_wait",       test_compute_wait);
     g_test_add_func("/throttle/init",               test_init);
+    g_test_add_func("/throttle/init_readonly",      test_init_readonly);
+    g_test_add_func("/throttle/init_writeonly",     test_init_writeonly);
     g_test_add_func("/throttle/destroy",            test_destroy);
     g_test_add_func("/throttle/have_timer",         test_have_timer);
     g_test_add_func("/throttle/detach_attach",      test_detach_attach);
-- 
2.34.1

[PATCH v4 5/9] cryptodev: use NULL throttle timer cb for read direction

[zhenwei pi]

Operations on a cryptodev are considered as *write* only, the callback
of read direction is never invoked. Use NULL instead of an unreachable
path(cryptodev_backend_throttle_timer_cb on read direction).

The dummy read timer(never invoked) is already removed here, it means
that the 'FIXME' tag is no longer needed.

Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Cc: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
---
 backends/cryptodev.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/backends/cryptodev.c b/backends/cryptodev.c
index 7d29517843..5cfa25c61c 100644
--- a/backends/cryptodev.c
+++ b/backends/cryptodev.c
@@ -331,8 +331,7 @@ static void cryptodev_backend_set_throttle(CryptoDevBackend *backend, int field,
     if (!enabled) {
         throttle_init(&backend->ts);
         throttle_timers_init(&backend->tt, qemu_get_aio_context(),
-                             QEMU_CLOCK_REALTIME,
-                             cryptodev_backend_throttle_timer_cb, /* FIXME */
+                             QEMU_CLOCK_REALTIME, NULL,
                              cryptodev_backend_throttle_timer_cb, backend);
     }
 
-- 
2.34.1

[PATCH v4 6/9] throttle: use enum ThrottleDirection instead of bool is_write

[zhenwei pi]

enum ThrottleDirection is already there, use ThrottleDirection instead
of 'bool is_write' for throttle API, also modify related codes from
block, fsdev, cryptodev and tests.

Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
---
 backends/cryptodev.c        |  9 +++++----
 block/throttle-groups.c     |  6 ++++--
 fsdev/qemu-fsdev-throttle.c |  8 +++++---
 include/qemu/throttle.h     |  5 +++--
 tests/unit/test-throttle.c  |  4 ++--
 util/throttle.c             | 31 +++++++++++++++++--------------
 6 files changed, 36 insertions(+), 27 deletions(-)

diff --git a/backends/cryptodev.c b/backends/cryptodev.c
index 5cfa25c61c..06142eae57 100644
--- a/backends/cryptodev.c
+++ b/backends/cryptodev.c
@@ -242,10 +242,11 @@ static void cryptodev_backend_throttle_timer_cb(void *opaque)
             continue;
         }
 
-        throttle_account(&backend->ts, true, ret);
+        throttle_account(&backend->ts, THROTTLE_WRITE, ret);
         cryptodev_backend_operation(backend, op_info);
         if (throttle_enabled(&backend->tc) &&
-            throttle_schedule_timer(&backend->ts, &backend->tt, true)) {
+            throttle_schedule_timer(&backend->ts, &backend->tt,
+                                    THROTTLE_WRITE)) {
             break;
         }
     }
@@ -261,7 +262,7 @@ int cryptodev_backend_crypto_operation(
         goto do_account;
     }
 
-    if (throttle_schedule_timer(&backend->ts, &backend->tt, true) ||
+    if (throttle_schedule_timer(&backend->ts, &backend->tt, THROTTLE_WRITE) ||
         !QTAILQ_EMPTY(&backend->opinfos)) {
         QTAILQ_INSERT_TAIL(&backend->opinfos, op_info, next);
         return 0;
@@ -273,7 +274,7 @@ do_account:
         return ret;
     }
 
-    throttle_account(&backend->ts, true, ret);
+    throttle_account(&backend->ts, THROTTLE_WRITE, ret);
 
     return cryptodev_backend_operation(backend, op_info);
 }
diff --git a/block/throttle-groups.c b/block/throttle-groups.c
index fb203c3ced..3847d27801 100644
--- a/block/throttle-groups.c
+++ b/block/throttle-groups.c
@@ -270,6 +270,7 @@ static bool throttle_group_schedule_timer(ThrottleGroupMember *tgm,
     ThrottleState *ts = tgm->throttle_state;
     ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
     ThrottleTimers *tt = &tgm->throttle_timers;
+    ThrottleDirection direction = is_write ? THROTTLE_WRITE : THROTTLE_READ;
     bool must_wait;
 
     if (qatomic_read(&tgm->io_limits_disabled)) {
@@ -281,7 +282,7 @@ static bool throttle_group_schedule_timer(ThrottleGroupMember *tgm,
         return true;
     }
 
-    must_wait = throttle_schedule_timer(ts, tt, is_write);
+    must_wait = throttle_schedule_timer(ts, tt, direction);
 
     /* If a timer just got armed, set tgm as the current token */
     if (must_wait) {
@@ -364,6 +365,7 @@ void coroutine_fn throttle_group_co_io_limits_intercept(ThrottleGroupMember *tgm
     bool must_wait;
     ThrottleGroupMember *token;
     ThrottleGroup *tg = container_of(tgm->throttle_state, ThrottleGroup, ts);
+    ThrottleDirection direction = is_write ? THROTTLE_WRITE : THROTTLE_READ;
 
     assert(bytes >= 0);
 
@@ -386,7 +388,7 @@ void coroutine_fn throttle_group_co_io_limits_intercept(ThrottleGroupMember *tgm
     }
 
     /* The I/O will be executed, so do the accounting */
-    throttle_account(tgm->throttle_state, is_write, bytes);
+    throttle_account(tgm->throttle_state, direction, bytes);
 
     /* Schedule the next request */
     schedule_next_request(tgm, is_write);
diff --git a/fsdev/qemu-fsdev-throttle.c b/fsdev/qemu-fsdev-throttle.c
index 5c83a1cc09..1c137d6f0f 100644
--- a/fsdev/qemu-fsdev-throttle.c
+++ b/fsdev/qemu-fsdev-throttle.c
@@ -97,16 +97,18 @@ void fsdev_throttle_init(FsThrottle *fst)
 void coroutine_fn fsdev_co_throttle_request(FsThrottle *fst, bool is_write,
                                             struct iovec *iov, int iovcnt)
 {
+    ThrottleDirection direction = is_write ? THROTTLE_WRITE : THROTTLE_READ;
+
     if (throttle_enabled(&fst->cfg)) {
-        if (throttle_schedule_timer(&fst->ts, &fst->tt, is_write) ||
+        if (throttle_schedule_timer(&fst->ts, &fst->tt, direction) ||
             !qemu_co_queue_empty(&fst->throttled_reqs[is_write])) {
             qemu_co_queue_wait(&fst->throttled_reqs[is_write], NULL);
         }
 
-        throttle_account(&fst->ts, is_write, iov_size(iov, iovcnt));
+        throttle_account(&fst->ts, direction, iov_size(iov, iovcnt));
 
         if (!qemu_co_queue_empty(&fst->throttled_reqs[is_write]) &&
-            !throttle_schedule_timer(&fst->ts, &fst->tt, is_write)) {
+            !throttle_schedule_timer(&fst->ts, &fst->tt, direction)) {
             qemu_co_queue_next(&fst->throttled_reqs[is_write]);
         }
     }
diff --git a/include/qemu/throttle.h b/include/qemu/throttle.h
index 9ca5ab8197..181245d29b 100644
--- a/include/qemu/throttle.h
+++ b/include/qemu/throttle.h
@@ -154,9 +154,10 @@ void throttle_config_init(ThrottleConfig *cfg);
 /* usage */
 bool throttle_schedule_timer(ThrottleState *ts,
                              ThrottleTimers *tt,
-                             bool is_write);
+                             ThrottleDirection direction);
 
-void throttle_account(ThrottleState *ts, bool is_write, uint64_t size);
+void throttle_account(ThrottleState *ts, ThrottleDirection direction,
+                      uint64_t size);
 void throttle_limits_to_config(ThrottleLimits *arg, ThrottleConfig *cfg,
                                Error **errp);
 void throttle_config_to_limits(ThrottleConfig *cfg, ThrottleLimits *var);
diff --git a/tests/unit/test-throttle.c b/tests/unit/test-throttle.c
index 5547837a58..2c4754fb8a 100644
--- a/tests/unit/test-throttle.c
+++ b/tests/unit/test-throttle.c
@@ -637,9 +637,9 @@ static bool do_test_accounting(bool is_ops, /* are we testing bps or ops */
     throttle_config(&ts, QEMU_CLOCK_VIRTUAL, &cfg);
 
     /* account a read */
-    throttle_account(&ts, false, size);
+    throttle_account(&ts, THROTTLE_READ, size);
     /* account a write */
-    throttle_account(&ts, true, size);
+    throttle_account(&ts, THROTTLE_WRITE, size);
 
     /* check total result */
     index = to_test[is_ops][0];
diff --git a/util/throttle.c b/util/throttle.c
index 0439028d21..9a37209bb8 100644
--- a/util/throttle.c
+++ b/util/throttle.c
@@ -136,11 +136,11 @@ int64_t throttle_compute_wait(LeakyBucket *bkt)
 
 /* This function compute the time that must be waited while this IO
  *
- * @is_write:   true if the current IO is a write, false if it's a read
+ * @throttle:   throttle direction
  * @ret:        time to wait
  */
 static int64_t throttle_compute_wait_for(ThrottleState *ts,
-                                         bool is_write)
+                                         ThrottleDirection direction)
 {
     BucketType to_check[2][4] = { {THROTTLE_BPS_TOTAL,
                                    THROTTLE_OPS_TOTAL,
@@ -154,7 +154,7 @@ static int64_t throttle_compute_wait_for(ThrottleState *ts,
     int i;
 
     for (i = 0; i < 4; i++) {
-        BucketType index = to_check[is_write][i];
+        BucketType index = to_check[direction][i];
         wait = throttle_compute_wait(&ts->cfg.buckets[index]);
         if (wait > max_wait) {
             max_wait = wait;
@@ -166,13 +166,13 @@ static int64_t throttle_compute_wait_for(ThrottleState *ts,
 
 /* compute the timer for this type of operation
  *
- * @is_write:   the type of operation
+ * @throttle:   throttle direction
  * @now:        the current clock timestamp
  * @next_timestamp: the resulting timer
  * @ret:        true if a timer must be set
  */
 static bool throttle_compute_timer(ThrottleState *ts,
-                                   bool is_write,
+                                   ThrottleDirection direction,
                                    int64_t now,
                                    int64_t *next_timestamp)
 {
@@ -182,7 +182,7 @@ static bool throttle_compute_timer(ThrottleState *ts,
     throttle_do_leak(ts, now);
 
     /* compute the wait time if any */
-    wait = throttle_compute_wait_for(ts, is_write);
+    wait = throttle_compute_wait_for(ts, direction);
 
     /* if the code must wait compute when the next timer should fire */
     if (wait) {
@@ -425,23 +425,24 @@ void throttle_get_config(ThrottleState *ts, ThrottleConfig *cfg)
  * NOTE: this function is not unit tested due to it's usage of timer_mod
  *
  * @tt:       the timers structure
- * @is_write: the type of operation (read/write)
+ * @throttle: throttle direction
  * @ret:      true if the timer has been scheduled else false
  */
 bool throttle_schedule_timer(ThrottleState *ts,
                              ThrottleTimers *tt,
-                             bool is_write)
+                             ThrottleDirection direction)
 {
     int64_t now = qemu_clock_get_ns(tt->clock_type);
     int64_t next_timestamp;
     QEMUTimer *timer;
     bool must_wait;
 
-    timer = is_write ? tt->timers[THROTTLE_WRITE] : tt->timers[THROTTLE_READ];
+    assert(direction < THROTTLE_MAX);
+    timer = tt->timers[direction];
     assert(timer);
 
     must_wait = throttle_compute_timer(ts,
-                                       is_write,
+                                       direction,
                                        now,
                                        &next_timestamp);
 
@@ -462,10 +463,11 @@ bool throttle_schedule_timer(ThrottleState *ts,
 
 /* do the accounting for this operation
  *
- * @is_write: the type of operation (read/write)
+ * @throttle: throttle direction
  * @size:     the size of the operation
  */
-void throttle_account(ThrottleState *ts, bool is_write, uint64_t size)
+void throttle_account(ThrottleState *ts, ThrottleDirection direction,
+                      uint64_t size)
 {
     const BucketType bucket_types_size[2][2] = {
         { THROTTLE_BPS_TOTAL, THROTTLE_BPS_READ },
@@ -478,6 +480,7 @@ void throttle_account(ThrottleState *ts, bool is_write, uint64_t size)
     double units = 1.0;
     unsigned i;
 
+    assert(direction < THROTTLE_MAX);
     /* if cfg.op_size is defined and smaller than size we compute unit count */
     if (ts->cfg.op_size && size > ts->cfg.op_size) {
         units = (double) size / ts->cfg.op_size;
@@ -486,13 +489,13 @@ void throttle_account(ThrottleState *ts, bool is_write, uint64_t size)
     for (i = 0; i < 2; i++) {
         LeakyBucket *bkt;
 
-        bkt = &ts->cfg.buckets[bucket_types_size[is_write][i]];
+        bkt = &ts->cfg.buckets[bucket_types_size[direction][i]];
         bkt->level += size;
         if (bkt->burst_length > 1) {
             bkt->burst_level += size;
         }
 
-        bkt = &ts->cfg.buckets[bucket_types_units[is_write][i]];
+        bkt = &ts->cfg.buckets[bucket_types_units[direction][i]];
         bkt->level += units;
         if (bkt->burst_length > 1) {
             bkt->burst_level += units;
-- 
2.34.1

[PATCH v4 7/9] throttle: use THROTTLE_MAX/ARRAY_SIZE for hard code

[zhenwei pi]

The first dimension of both to_check and
bucket_types_size/bucket_types_units is used as throttle direction,
use THROTTLE_MAX instead of hard coded number. Also use ARRAY_SIZE()
to avoid hard coded number for the second dimension.

Hanna noticed that the two array should be static. Yes, turn them
into static variables.

Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
---
 util/throttle.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/util/throttle.c b/util/throttle.c
index 9a37209bb8..9baa6b8a3a 100644
--- a/util/throttle.c
+++ b/util/throttle.c
@@ -142,7 +142,8 @@ int64_t throttle_compute_wait(LeakyBucket *bkt)
 static int64_t throttle_compute_wait_for(ThrottleState *ts,
                                          ThrottleDirection direction)
 {
-    BucketType to_check[2][4] = { {THROTTLE_BPS_TOTAL,
+    static const BucketType to_check[THROTTLE_MAX][4] = {
+                                  {THROTTLE_BPS_TOTAL,
                                    THROTTLE_OPS_TOTAL,
                                    THROTTLE_BPS_READ,
                                    THROTTLE_OPS_READ},
@@ -153,7 +154,7 @@ static int64_t throttle_compute_wait_for(ThrottleState *ts,
     int64_t wait, max_wait = 0;
     int i;
 
-    for (i = 0; i < 4; i++) {
+    for (i = 0; i < ARRAY_SIZE(to_check[THROTTLE_READ]); i++) {
         BucketType index = to_check[direction][i];
         wait = throttle_compute_wait(&ts->cfg.buckets[index]);
         if (wait > max_wait) {
@@ -469,11 +470,11 @@ bool throttle_schedule_timer(ThrottleState *ts,
 void throttle_account(ThrottleState *ts, ThrottleDirection direction,
                       uint64_t size)
 {
-    const BucketType bucket_types_size[2][2] = {
+    static const BucketType bucket_types_size[THROTTLE_MAX][2] = {
         { THROTTLE_BPS_TOTAL, THROTTLE_BPS_READ },
         { THROTTLE_BPS_TOTAL, THROTTLE_BPS_WRITE }
     };
-    const BucketType bucket_types_units[2][2] = {
+    static const BucketType bucket_types_units[THROTTLE_MAX][2] = {
         { THROTTLE_OPS_TOTAL, THROTTLE_OPS_READ },
         { THROTTLE_OPS_TOTAL, THROTTLE_OPS_WRITE }
     };
@@ -486,7 +487,7 @@ void throttle_account(ThrottleState *ts, ThrottleDirection direction,
         units = (double) size / ts->cfg.op_size;
     }
 
-    for (i = 0; i < 2; i++) {
+    for (i = 0; i < ARRAY_SIZE(bucket_types_size[THROTTLE_READ]); i++) {
         LeakyBucket *bkt;
 
         bkt = &ts->cfg.buckets[bucket_types_size[direction][i]];
-- 
2.34.1

[PATCH v4 8/9] fsdev: Use ThrottleDirection instread of bool is_write

[zhenwei pi]

'bool is_write' style is obsolete from throttle framework, adapt
fsdev to the new style.

Cc: Greg Kurz <groug@kaod.org>
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
---
 fsdev/qemu-fsdev-throttle.c | 14 +++++++-------
 fsdev/qemu-fsdev-throttle.h |  4 ++--
 hw/9pfs/cofile.c            |  4 ++--
 3 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/fsdev/qemu-fsdev-throttle.c b/fsdev/qemu-fsdev-throttle.c
index 1c137d6f0f..d912da906d 100644
--- a/fsdev/qemu-fsdev-throttle.c
+++ b/fsdev/qemu-fsdev-throttle.c
@@ -94,22 +94,22 @@ void fsdev_throttle_init(FsThrottle *fst)
     }
 }
 
-void coroutine_fn fsdev_co_throttle_request(FsThrottle *fst, bool is_write,
+void coroutine_fn fsdev_co_throttle_request(FsThrottle *fst,
+                                            ThrottleDirection direction,
                                             struct iovec *iov, int iovcnt)
 {
-    ThrottleDirection direction = is_write ? THROTTLE_WRITE : THROTTLE_READ;
-
+    assert(direction < THROTTLE_MAX);
     if (throttle_enabled(&fst->cfg)) {
         if (throttle_schedule_timer(&fst->ts, &fst->tt, direction) ||
-            !qemu_co_queue_empty(&fst->throttled_reqs[is_write])) {
-            qemu_co_queue_wait(&fst->throttled_reqs[is_write], NULL);
+            !qemu_co_queue_empty(&fst->throttled_reqs[direction])) {
+            qemu_co_queue_wait(&fst->throttled_reqs[direction], NULL);
         }
 
         throttle_account(&fst->ts, direction, iov_size(iov, iovcnt));
 
-        if (!qemu_co_queue_empty(&fst->throttled_reqs[is_write]) &&
+        if (!qemu_co_queue_empty(&fst->throttled_reqs[direction]) &&
             !throttle_schedule_timer(&fst->ts, &fst->tt, direction)) {
-            qemu_co_queue_next(&fst->throttled_reqs[is_write]);
+            qemu_co_queue_next(&fst->throttled_reqs[direction]);
         }
     }
 }
diff --git a/fsdev/qemu-fsdev-throttle.h b/fsdev/qemu-fsdev-throttle.h
index a21aecddc7..daa8ca2494 100644
--- a/fsdev/qemu-fsdev-throttle.h
+++ b/fsdev/qemu-fsdev-throttle.h
@@ -23,14 +23,14 @@ typedef struct FsThrottle {
     ThrottleState ts;
     ThrottleTimers tt;
     ThrottleConfig cfg;
-    CoQueue      throttled_reqs[2];
+    CoQueue      throttled_reqs[THROTTLE_MAX];
 } FsThrottle;
 
 int fsdev_throttle_parse_opts(QemuOpts *, FsThrottle *, Error **);
 
 void fsdev_throttle_init(FsThrottle *);
 
-void coroutine_fn fsdev_co_throttle_request(FsThrottle *, bool ,
+void coroutine_fn fsdev_co_throttle_request(FsThrottle *, ThrottleDirection ,
                                             struct iovec *, int);
 
 void fsdev_throttle_cleanup(FsThrottle *);
diff --git a/hw/9pfs/cofile.c b/hw/9pfs/cofile.c
index 9c5344039e..71174c3e4a 100644
--- a/hw/9pfs/cofile.c
+++ b/hw/9pfs/cofile.c
@@ -252,7 +252,7 @@ int coroutine_fn v9fs_co_pwritev(V9fsPDU *pdu, V9fsFidState *fidp,
     if (v9fs_request_cancelled(pdu)) {
         return -EINTR;
     }
-    fsdev_co_throttle_request(s->ctx.fst, true, iov, iovcnt);
+    fsdev_co_throttle_request(s->ctx.fst, THROTTLE_WRITE, iov, iovcnt);
     v9fs_co_run_in_worker(
         {
             err = s->ops->pwritev(&s->ctx, &fidp->fs, iov, iovcnt, offset);
@@ -272,7 +272,7 @@ int coroutine_fn v9fs_co_preadv(V9fsPDU *pdu, V9fsFidState *fidp,
     if (v9fs_request_cancelled(pdu)) {
         return -EINTR;
     }
-    fsdev_co_throttle_request(s->ctx.fst, false, iov, iovcnt);
+    fsdev_co_throttle_request(s->ctx.fst, THROTTLE_READ, iov, iovcnt);
     v9fs_co_run_in_worker(
         {
             err = s->ops->preadv(&s->ctx, &fidp->fs, iov, iovcnt, offset);
-- 
2.34.1

[PATCH v4 9/9] block/throttle-groups: Use ThrottleDirection instread of bool is_write

[zhenwei pi]

'bool is_write' style is obsolete from throttle framework, adapt
block throttle groups to the new style.

Use a simple python script to test the new style:
 #!/usr/bin/python3
import subprocess
import random
import time

commands = ['virsh blkdeviotune jammy vda --write-bytes-sec ', \
            'virsh blkdeviotune jammy vda --write-iops-sec ', \
            'virsh blkdeviotune jammy vda --read-bytes-sec ', \
            'virsh blkdeviotune jammy vda --read-iops-sec ']

for loop in range(1, 1000):
    time.sleep(random.randrange(3, 5))
    command = commands[random.randrange(0, 3)] + str(random.randrange(0, 1000000))
    subprocess.run(command, shell=True, check=True)

This works fine.

Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
---
 block/throttle-groups.c         | 105 ++++++++++++++++----------------
 block/throttle.c                |   8 +--
 include/block/throttle-groups.h |   6 +-
 3 files changed, 60 insertions(+), 59 deletions(-)

diff --git a/block/throttle-groups.c b/block/throttle-groups.c
index 3847d27801..c7c700fdb6 100644
--- a/block/throttle-groups.c
+++ b/block/throttle-groups.c
@@ -37,7 +37,7 @@
 
 static void throttle_group_obj_init(Object *obj);
 static void throttle_group_obj_complete(UserCreatable *obj, Error **errp);
-static void timer_cb(ThrottleGroupMember *tgm, bool is_write);
+static void timer_cb(ThrottleGroupMember *tgm, ThrottleDirection direction);
 
 /* The ThrottleGroup structure (with its ThrottleState) is shared
  * among different ThrottleGroupMembers and it's independent from
@@ -73,8 +73,8 @@ struct ThrottleGroup {
     QemuMutex lock; /* This lock protects the following four fields */
     ThrottleState ts;
     QLIST_HEAD(, ThrottleGroupMember) head;
-    ThrottleGroupMember *tokens[2];
-    bool any_timer_armed[2];
+    ThrottleGroupMember *tokens[THROTTLE_MAX];
+    bool any_timer_armed[THROTTLE_MAX];
     QEMUClockType clock_type;
 
     /* This field is protected by the global QEMU mutex */
@@ -197,13 +197,13 @@ static ThrottleGroupMember *throttle_group_next_tgm(ThrottleGroupMember *tgm)
  * This assumes that tg->lock is held.
  *
  * @tgm:        the ThrottleGroupMember
- * @is_write:   the type of operation (read/write)
+ * @direction:  the ThrottleDirection
  * @ret:        whether the ThrottleGroupMember has pending requests.
  */
 static inline bool tgm_has_pending_reqs(ThrottleGroupMember *tgm,
-                                        bool is_write)
+                                        ThrottleDirection direction)
 {
-    return tgm->pending_reqs[is_write];
+    return tgm->pending_reqs[direction];
 }
 
 /* Return the next ThrottleGroupMember in the round-robin sequence with pending
@@ -212,12 +212,12 @@ static inline bool tgm_has_pending_reqs(ThrottleGroupMember *tgm,
  * This assumes that tg->lock is held.
  *
  * @tgm:       the current ThrottleGroupMember
- * @is_write:  the type of operation (read/write)
+ * @direction: the ThrottleDirection
  * @ret:       the next ThrottleGroupMember with pending requests, or tgm if
  *             there is none.
  */
 static ThrottleGroupMember *next_throttle_token(ThrottleGroupMember *tgm,
-                                                bool is_write)
+                                                ThrottleDirection direction)
 {
     ThrottleState *ts = tgm->throttle_state;
     ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
@@ -227,16 +227,16 @@ static ThrottleGroupMember *next_throttle_token(ThrottleGroupMember *tgm,
      * it's being drained. Skip the round-robin search and return tgm
      * immediately if it has pending requests. Otherwise we could be
      * forcing it to wait for other member's throttled requests. */
-    if (tgm_has_pending_reqs(tgm, is_write) &&
+    if (tgm_has_pending_reqs(tgm, direction) &&
         qatomic_read(&tgm->io_limits_disabled)) {
         return tgm;
     }
 
-    start = token = tg->tokens[is_write];
+    start = token = tg->tokens[direction];
 
     /* get next bs round in round robin style */
     token = throttle_group_next_tgm(token);
-    while (token != start && !tgm_has_pending_reqs(token, is_write)) {
+    while (token != start && !tgm_has_pending_reqs(token, direction)) {
         token = throttle_group_next_tgm(token);
     }
 
@@ -244,12 +244,12 @@ static ThrottleGroupMember *next_throttle_token(ThrottleGroupMember *tgm,
      * then decide the token is the current tgm because chances are
      * the current tgm got the current request queued.
      */
-    if (token == start && !tgm_has_pending_reqs(token, is_write)) {
+    if (token == start && !tgm_has_pending_reqs(token, direction)) {
         token = tgm;
     }
 
     /* Either we return the original TGM, or one with pending requests */
-    assert(token == tgm || tgm_has_pending_reqs(token, is_write));
+    assert(token == tgm || tgm_has_pending_reqs(token, direction));
 
     return token;
 }
@@ -261,16 +261,15 @@ static ThrottleGroupMember *next_throttle_token(ThrottleGroupMember *tgm,
  * This assumes that tg->lock is held.
  *
  * @tgm:        the current ThrottleGroupMember
- * @is_write:   the type of operation (read/write)
+ * @direction:  the ThrottleDirection
  * @ret:        whether the I/O request needs to be throttled or not
  */
 static bool throttle_group_schedule_timer(ThrottleGroupMember *tgm,
-                                          bool is_write)
+                                          ThrottleDirection direction)
 {
     ThrottleState *ts = tgm->throttle_state;
     ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
     ThrottleTimers *tt = &tgm->throttle_timers;
-    ThrottleDirection direction = is_write ? THROTTLE_WRITE : THROTTLE_READ;
     bool must_wait;
 
     if (qatomic_read(&tgm->io_limits_disabled)) {
@@ -278,7 +277,7 @@ static bool throttle_group_schedule_timer(ThrottleGroupMember *tgm,
     }
 
     /* Check if any of the timers in this group is already armed */
-    if (tg->any_timer_armed[is_write]) {
+    if (tg->any_timer_armed[direction]) {
         return true;
     }
 
@@ -286,8 +285,8 @@ static bool throttle_group_schedule_timer(ThrottleGroupMember *tgm,
 
     /* If a timer just got armed, set tgm as the current token */
     if (must_wait) {
-        tg->tokens[is_write] = tgm;
-        tg->any_timer_armed[is_write] = true;
+        tg->tokens[direction] = tgm;
+        tg->any_timer_armed[direction] = true;
     }
 
     return must_wait;
@@ -297,15 +296,15 @@ static bool throttle_group_schedule_timer(ThrottleGroupMember *tgm,
  * any request was actually pending.
  *
  * @tgm:       the current ThrottleGroupMember
- * @is_write:  the type of operation (read/write)
+ * @direction: the ThrottleDirection
  */
 static bool coroutine_fn throttle_group_co_restart_queue(ThrottleGroupMember *tgm,
-                                                         bool is_write)
+                                                         ThrottleDirection direction)
 {
     bool ret;
 
     qemu_co_mutex_lock(&tgm->throttled_reqs_lock);
-    ret = qemu_co_queue_next(&tgm->throttled_reqs[is_write]);
+    ret = qemu_co_queue_next(&tgm->throttled_reqs[direction]);
     qemu_co_mutex_unlock(&tgm->throttled_reqs_lock);
 
     return ret;
@@ -316,9 +315,10 @@ static bool coroutine_fn throttle_group_co_restart_queue(ThrottleGroupMember *tg
  * This assumes that tg->lock is held.
  *
  * @tgm:       the current ThrottleGroupMember
- * @is_write:  the type of operation (read/write)
+ * @direction: the ThrottleDirection
  */
-static void schedule_next_request(ThrottleGroupMember *tgm, bool is_write)
+static void schedule_next_request(ThrottleGroupMember *tgm,
+                                  ThrottleDirection direction)
 {
     ThrottleState *ts = tgm->throttle_state;
     ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
@@ -326,27 +326,27 @@ static void schedule_next_request(ThrottleGroupMember *tgm, bool is_write)
     ThrottleGroupMember *token;
 
     /* Check if there's any pending request to schedule next */
-    token = next_throttle_token(tgm, is_write);
-    if (!tgm_has_pending_reqs(token, is_write)) {
+    token = next_throttle_token(tgm, direction);
+    if (!tgm_has_pending_reqs(token, direction)) {
         return;
     }
 
     /* Set a timer for the request if it needs to be throttled */
-    must_wait = throttle_group_schedule_timer(token, is_write);
+    must_wait = throttle_group_schedule_timer(token, direction);
 
     /* If it doesn't have to wait, queue it for immediate execution */
     if (!must_wait) {
         /* Give preference to requests from the current tgm */
         if (qemu_in_coroutine() &&
-            throttle_group_co_restart_queue(tgm, is_write)) {
+            throttle_group_co_restart_queue(tgm, direction)) {
             token = tgm;
         } else {
             ThrottleTimers *tt = &token->throttle_timers;
             int64_t now = qemu_clock_get_ns(tg->clock_type);
-            timer_mod(tt->timers[is_write], now);
-            tg->any_timer_armed[is_write] = true;
+            timer_mod(tt->timers[direction], now);
+            tg->any_timer_armed[direction] = true;
         }
-        tg->tokens[is_write] = token;
+        tg->tokens[direction] = token;
     }
 }
 
@@ -356,49 +356,49 @@ static void schedule_next_request(ThrottleGroupMember *tgm, bool is_write)
  *
  * @tgm:       the current ThrottleGroupMember
  * @bytes:     the number of bytes for this I/O
- * @is_write:  the type of operation (read/write)
+ * @direction: the ThrottleDirection
  */
 void coroutine_fn throttle_group_co_io_limits_intercept(ThrottleGroupMember *tgm,
                                                         int64_t bytes,
-                                                        bool is_write)
+                                                        ThrottleDirection direction)
 {
     bool must_wait;
     ThrottleGroupMember *token;
     ThrottleGroup *tg = container_of(tgm->throttle_state, ThrottleGroup, ts);
-    ThrottleDirection direction = is_write ? THROTTLE_WRITE : THROTTLE_READ;
 
     assert(bytes >= 0);
+    assert(direction < THROTTLE_MAX);
 
     qemu_mutex_lock(&tg->lock);
 
     /* First we check if this I/O has to be throttled. */
-    token = next_throttle_token(tgm, is_write);
-    must_wait = throttle_group_schedule_timer(token, is_write);
+    token = next_throttle_token(tgm, direction);
+    must_wait = throttle_group_schedule_timer(token, direction);
 
     /* Wait if there's a timer set or queued requests of this type */
-    if (must_wait || tgm->pending_reqs[is_write]) {
-        tgm->pending_reqs[is_write]++;
+    if (must_wait || tgm->pending_reqs[direction]) {
+        tgm->pending_reqs[direction]++;
         qemu_mutex_unlock(&tg->lock);
         qemu_co_mutex_lock(&tgm->throttled_reqs_lock);
-        qemu_co_queue_wait(&tgm->throttled_reqs[is_write],
+        qemu_co_queue_wait(&tgm->throttled_reqs[direction],
                            &tgm->throttled_reqs_lock);
         qemu_co_mutex_unlock(&tgm->throttled_reqs_lock);
         qemu_mutex_lock(&tg->lock);
-        tgm->pending_reqs[is_write]--;
+        tgm->pending_reqs[direction]--;
     }
 
     /* The I/O will be executed, so do the accounting */
     throttle_account(tgm->throttle_state, direction, bytes);
 
     /* Schedule the next request */
-    schedule_next_request(tgm, is_write);
+    schedule_next_request(tgm, direction);
 
     qemu_mutex_unlock(&tg->lock);
 }
 
 typedef struct {
     ThrottleGroupMember *tgm;
-    bool is_write;
+    ThrottleDirection direction;
 } RestartData;
 
 static void coroutine_fn throttle_group_restart_queue_entry(void *opaque)
@@ -407,16 +407,16 @@ static void coroutine_fn throttle_group_restart_queue_entry(void *opaque)
     ThrottleGroupMember *tgm = data->tgm;
     ThrottleState *ts = tgm->throttle_state;
     ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
-    bool is_write = data->is_write;
+    ThrottleDirection direction = data->direction;
     bool empty_queue;
 
-    empty_queue = !throttle_group_co_restart_queue(tgm, is_write);
+    empty_queue = !throttle_group_co_restart_queue(tgm, direction);
 
     /* If the request queue was empty then we have to take care of
      * scheduling the next one */
     if (empty_queue) {
         qemu_mutex_lock(&tg->lock);
-        schedule_next_request(tgm, is_write);
+        schedule_next_request(tgm, direction);
         qemu_mutex_unlock(&tg->lock);
     }
 
@@ -426,18 +426,19 @@ static void coroutine_fn throttle_group_restart_queue_entry(void *opaque)
     aio_wait_kick();
 }
 
-static void throttle_group_restart_queue(ThrottleGroupMember *tgm, bool is_write)
+static void throttle_group_restart_queue(ThrottleGroupMember *tgm,
+                                        ThrottleDirection direction)
 {
     Coroutine *co;
     RestartData *rd = g_new0(RestartData, 1);
 
     rd->tgm = tgm;
-    rd->is_write = is_write;
+    rd->direction = direction;
 
     /* This function is called when a timer is fired or when
      * throttle_group_restart_tgm() is called. Either way, there can
      * be no timer pending on this tgm at this point */
-    assert(!timer_pending(tgm->throttle_timers.timers[is_write]));
+    assert(!timer_pending(tgm->throttle_timers.timers[direction]));
 
     qatomic_inc(&tgm->restart_pending);
 
@@ -502,20 +503,20 @@ void throttle_group_get_config(ThrottleGroupMember *tgm, ThrottleConfig *cfg)
  * because it had been throttled.
  *
  * @tgm:       the ThrottleGroupMember whose request had been throttled
- * @is_write:  the type of operation (read/write)
+ * @direction: the ThrottleDirection
  */
-static void timer_cb(ThrottleGroupMember *tgm, bool is_write)
+static void timer_cb(ThrottleGroupMember *tgm, ThrottleDirection direction)
 {
     ThrottleState *ts = tgm->throttle_state;
     ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
 
     /* The timer has just been fired, so we can update the flag */
     qemu_mutex_lock(&tg->lock);
-    tg->any_timer_armed[is_write] = false;
+    tg->any_timer_armed[direction] = false;
     qemu_mutex_unlock(&tg->lock);
 
     /* Run the request that was waiting for this timer */
-    throttle_group_restart_queue(tgm, is_write);
+    throttle_group_restart_queue(tgm, direction);
 }
 
 static void read_timer_cb(void *opaque)
diff --git a/block/throttle.c b/block/throttle.c
index 3aaef18d4e..1098a4ae9a 100644
--- a/block/throttle.c
+++ b/block/throttle.c
@@ -118,7 +118,7 @@ throttle_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes,
 {
 
     ThrottleGroupMember *tgm = bs->opaque;
-    throttle_group_co_io_limits_intercept(tgm, bytes, false);
+    throttle_group_co_io_limits_intercept(tgm, bytes, THROTTLE_READ);
 
     return bdrv_co_preadv(bs->file, offset, bytes, qiov, flags);
 }
@@ -128,7 +128,7 @@ throttle_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes,
                     QEMUIOVector *qiov, BdrvRequestFlags flags)
 {
     ThrottleGroupMember *tgm = bs->opaque;
-    throttle_group_co_io_limits_intercept(tgm, bytes, true);
+    throttle_group_co_io_limits_intercept(tgm, bytes, THROTTLE_WRITE);
 
     return bdrv_co_pwritev(bs->file, offset, bytes, qiov, flags);
 }
@@ -138,7 +138,7 @@ throttle_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int64_t bytes,
                           BdrvRequestFlags flags)
 {
     ThrottleGroupMember *tgm = bs->opaque;
-    throttle_group_co_io_limits_intercept(tgm, bytes, true);
+    throttle_group_co_io_limits_intercept(tgm, bytes, THROTTLE_WRITE);
 
     return bdrv_co_pwrite_zeroes(bs->file, offset, bytes, flags);
 }
@@ -147,7 +147,7 @@ static int coroutine_fn GRAPH_RDLOCK
 throttle_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes)
 {
     ThrottleGroupMember *tgm = bs->opaque;
-    throttle_group_co_io_limits_intercept(tgm, bytes, true);
+    throttle_group_co_io_limits_intercept(tgm, bytes, THROTTLE_WRITE);
 
     return bdrv_co_pdiscard(bs->file, offset, bytes);
 }
diff --git a/include/block/throttle-groups.h b/include/block/throttle-groups.h
index ff282fc0f8..2355e8d9de 100644
--- a/include/block/throttle-groups.h
+++ b/include/block/throttle-groups.h
@@ -37,7 +37,7 @@ typedef struct ThrottleGroupMember {
     AioContext   *aio_context;
     /* throttled_reqs_lock protects the CoQueues for throttled requests.  */
     CoMutex      throttled_reqs_lock;
-    CoQueue      throttled_reqs[2];
+    CoQueue      throttled_reqs[THROTTLE_MAX];
 
     /* Nonzero if the I/O limits are currently being ignored; generally
      * it is zero.  Accessed with atomic operations.
@@ -54,7 +54,7 @@ typedef struct ThrottleGroupMember {
      * throttle_state tells us if I/O limits are configured. */
     ThrottleState *throttle_state;
     ThrottleTimers throttle_timers;
-    unsigned       pending_reqs[2];
+    unsigned       pending_reqs[THROTTLE_MAX];
     QLIST_ENTRY(ThrottleGroupMember) round_robin;
 
 } ThrottleGroupMember;
@@ -78,7 +78,7 @@ void throttle_group_restart_tgm(ThrottleGroupMember *tgm);
 
 void coroutine_fn throttle_group_co_io_limits_intercept(ThrottleGroupMember *tgm,
                                                         int64_t bytes,
-                                                        bool is_write);
+                                                        ThrottleDirection direction);
 void throttle_group_attach_aio_context(ThrottleGroupMember *tgm,
                                        AioContext *new_context);
 void throttle_group_detach_aio_context(ThrottleGroupMember *tgm);
-- 
2.34.1

Re: [PATCH v4 6/9] throttle: use enum ThrottleDirection instead of bool is_write

[Hanna Czenczek]

On 24.07.23 12:09, zhenwei pi wrote:
> enum ThrottleDirection is already there, use ThrottleDirection instead
> of 'bool is_write' for throttle API, also modify related codes from
> block, fsdev, cryptodev and tests.
>
> Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
> ---
>   backends/cryptodev.c        |  9 +++++----
>   block/throttle-groups.c     |  6 ++++--
>   fsdev/qemu-fsdev-throttle.c |  8 +++++---
>   include/qemu/throttle.h     |  5 +++--
>   tests/unit/test-throttle.c  |  4 ++--
>   util/throttle.c             | 31 +++++++++++++++++--------------
>   6 files changed, 36 insertions(+), 27 deletions(-)

[...]

> diff --git a/util/throttle.c b/util/throttle.c
> index 0439028d21..9a37209bb8 100644
> --- a/util/throttle.c
> +++ b/util/throttle.c
> @@ -136,11 +136,11 @@ int64_t throttle_compute_wait(LeakyBucket *bkt)
>   
>   /* This function compute the time that must be waited while this IO
>    *
> - * @is_write:   true if the current IO is a write, false if it's a read
> + * @throttle:   throttle direction

The parameter is now named @direction, so this should be changed. (Same 
in all other comments describing functions in this patch.)

With that done (in all 4 places):

Reviewed-by: Hanna Czenczek <hreitz@redhat.com>

>    * @ret:        time to wait
>    */
>   static int64_t throttle_compute_wait_for(ThrottleState *ts,
> -                                         bool is_write)
> +                                         ThrottleDirection direction)
>   {
>       BucketType to_check[2][4] = { {THROTTLE_BPS_TOTAL,
>                                      THROTTLE_OPS_TOTAL,

Re: [PATCH v4 7/9] throttle: use THROTTLE_MAX/ARRAY_SIZE for hard code

[Hanna Czenczek]

On 24.07.23 12:09, zhenwei pi wrote:
> The first dimension of both to_check and
> bucket_types_size/bucket_types_units is used as throttle direction,
> use THROTTLE_MAX instead of hard coded number. Also use ARRAY_SIZE()
> to avoid hard coded number for the second dimension.
>
> Hanna noticed that the two array should be static. Yes, turn them
> into static variables.
>
> Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
> ---
>   util/throttle.c | 11 ++++++-----
>   1 file changed, 6 insertions(+), 5 deletions(-)

Using ARRAY_SIZE() for the other dimension is quite nice, too, indeed.  
Thanks!

Reviewed-by: Hanna Czenczek <hreitz@redhat.com>

Re: [PATCH v4 8/9] fsdev: Use ThrottleDirection instread of bool is_write

[Hanna Czenczek]

On 24.07.23 12:09, zhenwei pi wrote:
> 'bool is_write' style is obsolete from throttle framework, adapt
> fsdev to the new style.
>
> Cc: Greg Kurz <groug@kaod.org>
> Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
> ---
>   fsdev/qemu-fsdev-throttle.c | 14 +++++++-------
>   fsdev/qemu-fsdev-throttle.h |  4 ++--
>   hw/9pfs/cofile.c            |  4 ++--
>   3 files changed, 11 insertions(+), 11 deletions(-)

Reviewed-by: Hanna Czenczek <hreitz@redhat.com>

Re: [PATCH v4 9/9] block/throttle-groups: Use ThrottleDirection instread of bool is_write

[Hanna Czenczek]

On 24.07.23 12:09, zhenwei pi wrote:
> 'bool is_write' style is obsolete from throttle framework, adapt
> block throttle groups to the new style.
>
> Use a simple python script to test the new style:
>   #!/usr/bin/python3
> import subprocess
> import random
> import time
>
> commands = ['virsh blkdeviotune jammy vda --write-bytes-sec ', \
>              'virsh blkdeviotune jammy vda --write-iops-sec ', \
>              'virsh blkdeviotune jammy vda --read-bytes-sec ', \
>              'virsh blkdeviotune jammy vda --read-iops-sec ']
>
> for loop in range(1, 1000):
>      time.sleep(random.randrange(3, 5))
>      command = commands[random.randrange(0, 3)] + str(random.randrange(0, 1000000))
>      subprocess.run(command, shell=True, check=True)
>
> This works fine.
>
> Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
> ---
>   block/throttle-groups.c         | 105 ++++++++++++++++----------------
>   block/throttle.c                |   8 +--
>   include/block/throttle-groups.h |   6 +-
>   3 files changed, 60 insertions(+), 59 deletions(-)
>
> diff --git a/block/throttle-groups.c b/block/throttle-groups.c
> index 3847d27801..c7c700fdb6 100644
> --- a/block/throttle-groups.c
> +++ b/block/throttle-groups.c

Thanks a lot!  The changes done look good, and I think they’re nice.

There are some functions left untouched, though, which I think should 
use ThrottleDirection, too:

throttle_group_register_tgm() should use THROTTLE_READ/THROTTLE_WRITE to 
index tgm->throttled_reqs[] (instead of 0/1).  It also has a `for (i = 
0; i < 2; i++)` loop over tg->tokens[], which probably should use 
THROTTLE_MAX as the upper limit, or iterate over a ThrottleDirection 
variable altogether (as you’ve done it in patch 3 e.g. for 
throttle_timers_attach_aio_context()).

throttle_group_unregister_tgm() has such a loop, too (over 
tgm->pending_reqs[], tgm->throttled_reqs[], 
tgm->throttle_timers.timers[], and tg->tokens[], all of which are arrays 
over ThrottleDirection).

throttle_group_detach_aio_context() also has both the indexing “problem” 
(integers instead of THROTTLE_* for tgm->pending_reqs[] and 
tgm->throttled_reqs[]) and such a loop.  There, the loop probably really 
should be over a ThrottleDirection variable, because it passes that 
variable to schedule_next_request().

throttle_group_restart_tgm() also has such a loop, it uses that variable 
to index tgm->throttle_timers.timers[], and passes it to both timer_cb() 
and throttle_group_restart_queue().

read_timer_cb() and write_timer_cb() should call timer_cb() with 
THROTTLE_READ/THROTTLE_WRITE instead of false/true.

> diff --git a/include/block/throttle-groups.h b/include/block/throttle-groups.h
> index ff282fc0f8..2355e8d9de 100644
> --- a/include/block/throttle-groups.h
> +++ b/include/block/throttle-groups.h

[...]

> @@ -78,7 +78,7 @@ void throttle_group_restart_tgm(ThrottleGroupMember *tgm);
>   
>   void coroutine_fn throttle_group_co_io_limits_intercept(ThrottleGroupMember *tgm,
>                                                           int64_t bytes,
> -                                                        bool is_write);
> +                                                        ThrottleDirection direction);

block/block-backend.c calls this function in 
blk_co_do_p{read,write}v_part(), those calls need to be adjusted, too.

>   void throttle_group_attach_aio_context(ThrottleGroupMember *tgm,
>                                          AioContext *new_context);
>   void throttle_group_detach_aio_context(ThrottleGroupMember *tgm);

Re: Re: [PATCH v4 9/9] block/throttle-groups: Use ThrottleDirection instread of bool is_write

[zhenwei pi]

On 7/28/23 00:12, Hanna Czenczek wrote:
> On 24.07.23 12:09, zhenwei pi wrote:
>> 'bool is_write' style is obsolete from throttle framework, adapt
>> block throttle groups to the new style.
>>
>> Use a simple python script to test the new style:
>>   #!/usr/bin/python3
>> import subprocess
>> import random
>> import time
>>
>> commands = ['virsh blkdeviotune jammy vda --write-bytes-sec ', \
>>              'virsh blkdeviotune jammy vda --write-iops-sec ', \
>>              'virsh blkdeviotune jammy vda --read-bytes-sec ', \
>>              'virsh blkdeviotune jammy vda --read-iops-sec ']
>>
>> for loop in range(1, 1000):
>>      time.sleep(random.randrange(3, 5))
>>      command = commands[random.randrange(0, 3)] + 
>> str(random.randrange(0, 1000000))
>>      subprocess.run(command, shell=True, check=True)
>>
>> This works fine.
>>
>> Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
>> ---
>>   block/throttle-groups.c         | 105 ++++++++++++++++----------------
>>   block/throttle.c                |   8 +--
>>   include/block/throttle-groups.h |   6 +-
>>   3 files changed, 60 insertions(+), 59 deletions(-)
>>
>> diff --git a/block/throttle-groups.c b/block/throttle-groups.c
>> index 3847d27801..c7c700fdb6 100644
>> --- a/block/throttle-groups.c
>> +++ b/block/throttle-groups.c
> 
> Thanks a lot!  The changes done look good, and I think they’re nice.
> 
> There are some functions left untouched, though, which I think should 
> use ThrottleDirection, too:
> 
> throttle_group_register_tgm() should use THROTTLE_READ/THROTTLE_WRITE to 
> index tgm->throttled_reqs[] (instead of 0/1).  It also has a `for (i = 
> 0; i < 2; i++)` loop over tg->tokens[], which probably should use 
> THROTTLE_MAX as the upper limit, or iterate over a ThrottleDirection 
> variable altogether (as you’ve done it in patch 3 e.g. for 
> throttle_timers_attach_aio_context()).
> 
> throttle_group_unregister_tgm() has such a loop, too (over 
> tgm->pending_reqs[], tgm->throttled_reqs[], 
> tgm->throttle_timers.timers[], and tg->tokens[], all of which are arrays 
> over ThrottleDirection).
> 
> throttle_group_detach_aio_context() also has both the indexing “problem” 
> (integers instead of THROTTLE_* for tgm->pending_reqs[] and 
> tgm->throttled_reqs[]) and such a loop.  There, the loop probably really 
> should be over a ThrottleDirection variable, because it passes that 
> variable to schedule_next_request().
> 
> throttle_group_restart_tgm() also has such a loop, it uses that variable 
> to index tgm->throttle_timers.timers[], and passes it to both timer_cb() 
> and throttle_group_restart_queue().
> 
> read_timer_cb() and write_timer_cb() should call timer_cb() with 
> THROTTLE_READ/THROTTLE_WRITE instead of false/true.
> 
>> diff --git a/include/block/throttle-groups.h 
>> b/include/block/throttle-groups.h
>> index ff282fc0f8..2355e8d9de 100644
>> --- a/include/block/throttle-groups.h
>> +++ b/include/block/throttle-groups.h
> 
> [...]
> 
>> @@ -78,7 +78,7 @@ void throttle_group_restart_tgm(ThrottleGroupMember 
>> *tgm);
>>   void coroutine_fn 
>> throttle_group_co_io_limits_intercept(ThrottleGroupMember *tgm,
>>                                                           int64_t bytes,
>> -                                                        bool is_write);
>> +                                                        
>> ThrottleDirection direction);
> 
> block/block-backend.c calls this function in 
> blk_co_do_p{read,write}v_part(), those calls need to be adjusted, too.
> 
>>   void throttle_group_attach_aio_context(ThrottleGroupMember *tgm,
>>                                          AioContext *new_context);
>>   void throttle_group_detach_aio_context(ThrottleGroupMember *tgm);
> 

Sorry, I missed these. Please see the v5 version. Thanks!

-- 
zhenwei pi