block/throttle-groups: Use ThrottleDirection instread of bool is_write

'bool is_write' style is obsolete from throttle framework, adapt
block throttle groups to the new style:
- use ThrottleDirection instead of 'bool is_write'. Ex,
  schedule_next_request(ThrottleGroupMember *tgm, bool is_write)
  -> schedule_next_request(ThrottleGroupMember *tgm, ThrottleDirection direction)

- use THROTTLE_MAX instead of hard code. Ex, ThrottleGroupMember *tokens[2]
  -> ThrottleGroupMember *tokens[THROTTLE_MAX]

- use ThrottleDirection instead of hard code on iteration. Ex, (i = 0; i < 2; i++)
  -> for (dir = THROTTLE_READ; dir < THROTTLE_MAX; dir++)

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>
Message-Id: <20230728022006.1098509-10-pizhenwei@bytedance.com>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>

1 files changed, 3 insertions, 3 deletions

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);