git: 75b03f73b4a0 - stable/14 - vfs cache: sanitize debug counters

[Mateusz Guzik]

The branch stable/14 has been updated by mjg:

URL: 
https://cgit.FreeBSD.org/src/commit/?id=75b03f73b4a0f94090aa9fd050e82089c83fe2bb

commit 75b03f73b4a0f94090aa9fd050e82089c83fe2bb
Author:     Mateusz Guzik <m...@freebsd.org>
AuthorDate: 2023-10-05 12:16:18 +0000
Commit:     Mateusz Guzik <m...@freebsd.org>
CommitDate: 2023-10-09 23:19:00 +0000

    vfs cache: sanitize debug counters
    
    They are very rarely triggered, so no need for per-cpu distribution.
    
    At the same time the non-cpu ones still should use atomics to not lose
    any updates.
    
    (cherry picked from commit 2749c222da8a6325d39c0571f72b1dbed2f7d583)
---
 sys/kern/vfs_cache.c | 21 +++++++++------------
 1 file changed, 9 insertions(+), 12 deletions(-)

diff --git a/sys/kern/vfs_cache.c b/sys/kern/vfs_cache.c
index 7e059d374c31..38a39331e237 100644
--- a/sys/kern/vfs_cache.c
+++ b/sys/kern/vfs_cache.c
@@ -553,17 +553,14 @@ static SYSCTL_NODE(_vfs_cache, OID_AUTO, debug, 
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
     "Name cache debugging");
 #define DEBUGNODE_ULONG(name, varname, descr)                                  
\
        SYSCTL_ULONG(_vfs_cache_debug, OID_AUTO, name, CTLFLAG_RD, &varname, 0, 
descr);
-#define DEBUGNODE_COUNTER(name, varname, descr)                                
        \
-       static COUNTER_U64_DEFINE_EARLY(varname);                               
\
-       SYSCTL_COUNTER_U64(_vfs_cache_debug, OID_AUTO, name, CTLFLAG_RD, 
&varname, \
-           descr);
-DEBUGNODE_COUNTER(zap_bucket_relock_success, zap_bucket_relock_success,
+static u_long zap_bucket_relock_success;
+DEBUGNODE_ULONG(zap_bucket_relock_success, zap_bucket_relock_success,
     "Number of successful removals after relocking");
-static long zap_bucket_fail;
+static u_long zap_bucket_fail;
 DEBUGNODE_ULONG(zap_bucket_fail, zap_bucket_fail, "");
-static long zap_bucket_fail2;
+static u_long zap_bucket_fail2;
 DEBUGNODE_ULONG(zap_bucket_fail2, zap_bucket_fail2, "");
-static long cache_lock_vnodes_cel_3_failures;
+static u_long cache_lock_vnodes_cel_3_failures;
 DEBUGNODE_ULONG(vnodes_cel_3_failures, cache_lock_vnodes_cel_3_failures,
     "Number of times 3-way vnode locking failed");
 
@@ -1664,7 +1661,7 @@ cache_zap_unlocked_bucket(struct namecache *ncp, struct 
componentname *cnp,
                cache_zap_locked(rncp);
                mtx_unlock(blp);
                cache_unlock_vnodes(dvlp, vlp);
-               counter_u64_add(zap_bucket_relock_success, 1);
+               atomic_add_long(&zap_bucket_relock_success, 1);
                return (0);
        }
 
@@ -1760,7 +1757,7 @@ retry:
 
        error = cache_zap_locked_bucket(ncp, cnp, hash, blp);
        if (__predict_false(error != 0)) {
-               zap_bucket_fail++;
+               atomic_add_long(&zap_bucket_fail, 1);
                goto retry;
        }
        counter_u64_add(numposzaps, 1);
@@ -1986,7 +1983,7 @@ negative_success:
                        counter_u64_add(numnegzaps, 1);
                        error = cache_zap_locked_bucket(ncp, cnp, hash, blp);
                        if (__predict_false(error != 0)) {
-                               zap_bucket_fail2++;
+                               atomic_add_long(&zap_bucket_fail2, 1);
                                goto retry;
                        }
                        cache_free(ncp);
@@ -2184,8 +2181,8 @@ cache_lock_vnodes_cel_3(struct celockstate *cel, struct 
vnode *vp)
        } else {
                if (mtx_trylock(vlp))
                        goto out;
-               cache_lock_vnodes_cel_3_failures++;
                cache_unlock_vnodes_cel(cel);
+               atomic_add_long(&cache_lock_vnodes_cel_3_failures, 1);
                if (vlp < cel->vlp[0]) {
                        mtx_lock(vlp);
                        mtx_lock(cel->vlp[0]);