git: 75447afca868 - main - rangelocks: extract the cheat mode drain code

[Konstantin Belousov]

The branch main has been updated by kib:

URL: 
https://cgit.FreeBSD.org/src/commit/?id=75447afca868f82f1c53c5be32dccd777813ec1a

commit 75447afca868f82f1c53c5be32dccd777813ec1a
Author:     Konstantin Belousov <k...@freebsd.org>
AuthorDate: 2024-08-27 21:32:51 +0000
Commit:     Konstantin Belousov <k...@freebsd.org>
CommitDate: 2024-08-28 14:33:46 +0000

    rangelocks: extract the cheat mode drain code
    
    Reviewed by:    markj
    Tested by:      lwhsu
    Sponsored by:   The FreeBSD Foundation
    Differential revision:  https://reviews.freebsd.org/D46465
---
 sys/kern/kern_rangelock.c | 30 +++++++++++++++++++-----------
 1 file changed, 19 insertions(+), 11 deletions(-)

diff --git a/sys/kern/kern_rangelock.c b/sys/kern/kern_rangelock.c
index 38449f71a8b7..0e62b91b4ee7 100644
--- a/sys/kern/kern_rangelock.c
+++ b/sys/kern/kern_rangelock.c
@@ -82,6 +82,24 @@ SYSCTL_INT(_debug, OID_AUTO, rangelock_cheat, CTLFLAG_RWTUN,
 #define        RL_RET_CHEAT_RLOCKED    0x1100
 #define        RL_RET_CHEAT_WLOCKED    0x2200
 
+static void
+rangelock_cheat_drain(struct rangelock *lock)
+{
+       uintptr_t v;
+
+       DROP_GIANT();
+       for (;;) {
+               v = (uintptr_t)atomic_load_ptr(&lock->head);
+               if ((v & RL_CHEAT_DRAINING) == 0)
+                       break;
+               sleepq_add(&lock->head, NULL, "ranged1", 0, 0);
+               sleepq_wait(&lock->head, PRI_USER);
+               sleepq_lock(&lock->head);
+       }
+       sleepq_release(&lock->head);
+       PICKUP_GIANT();
+}
+
 static bool
 rangelock_cheat_lock(struct rangelock *lock, int locktype, bool trylock,
     void **cookie)
@@ -99,17 +117,7 @@ drain:
                }
                sleepq_lock(&lock->head);
 drain1:
-               DROP_GIANT();
-               for (;;) {
-                       v = (uintptr_t)atomic_load_ptr(&lock->head);
-                       if ((v & RL_CHEAT_DRAINING) == 0)
-                               break;
-                       sleepq_add(&lock->head, NULL, "ranged1", 0, 0);
-                       sleepq_wait(&lock->head, PRI_USER);
-                       sleepq_lock(&lock->head);
-               }
-               sleepq_release(&lock->head);
-               PICKUP_GIANT();
+               rangelock_cheat_drain(lock);
                return (false);
        }