git: 245767c2782e - main - vfs: flip deferred_inact to atomic

The branch main has been updated by mjg:

URL: https://cgit.FreeBSD.org/src/commit/?id=245767c2782ef2e29340be0a6755be817f16bad4

commit 245767c2782ef2e29340be0a6755be817f16bad4
Author:     Mateusz Guzik <mjg@FreeBSD.org>
AuthorDate: 2023-03-25 13:31:17 +0000
Commit:     Mateusz Guzik <mjg@FreeBSD.org>
CommitDate: 2023-03-25 13:42:27 +0000

    vfs: flip deferred_inact to atomic
    
    Turns out it is very rarely triggered, making a per-cpu
    counter a waste.
    
    Examples from real life boxes:
    uptime          counter
    135 days        847
    138 days        2190
    141 days        1
---
 sys/kern/vfs_subr.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c
index f8a871906e0f..72be478e310d 100644
--- a/sys/kern/vfs_subr.c
+++ b/sys/kern/vfs_subr.c
@@ -198,9 +198,9 @@ static counter_u64_t recycles_free_count;
 SYSCTL_COUNTER_U64(_vfs, OID_AUTO, recycles_free, CTLFLAG_RD, &recycles_free_count,
     "Number of free vnodes recycled to meet vnode cache targets");
 
-static counter_u64_t deferred_inact;
-SYSCTL_COUNTER_U64(_vfs, OID_AUTO, deferred_inact, CTLFLAG_RD, &deferred_inact,
-    "Number of times inactive processing was deferred");
+static u_long deferred_inact;
+SYSCTL_ULONG(_vfs, OID_AUTO, deferred_inact, CTLFLAG_RD,
+    &deferred_inact, 0, "Number of times inactive processing was deferred");
 
 /* To keep more than one thread at a time from running vfs_getnewfsid */
 static struct mtx mntid_mtx;
@@ -734,7 +734,6 @@ vntblinit(void *dummy __unused)
 	vnodes_created = counter_u64_alloc(M_WAITOK);
 	recycles_count = counter_u64_alloc(M_WAITOK);
 	recycles_free_count = counter_u64_alloc(M_WAITOK);
-	deferred_inact = counter_u64_alloc(M_WAITOK);
 
 	/*
 	 * Initialize the filesystem syncer.
@@ -3211,7 +3210,7 @@ vdefer_inactive(struct vnode *vp)
 	vlazy(vp);
 	vp->v_iflag |= VI_DEFINACT;
 	VI_UNLOCK(vp);
-	counter_u64_add(deferred_inact, 1);
+	atomic_add_long(&deferred_inact, 1);
 }
 
 static void