Module Name: src
Committed By: simonb
Date: Thu Apr 1 06:26:00 UTC 2021
Modified Files:
src/sys/kern: vfs_bio.c
Log Message:
Add a sysctl hashstat collector for bufhash.
To generate a diff of this commit:
cvs rdiff -u -r1.297 -r1.298 src/sys/kern/vfs_bio.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/vfs_bio.c
diff -u src/sys/kern/vfs_bio.c:1.297 src/sys/kern/vfs_bio.c:1.298
--- src/sys/kern/vfs_bio.c:1.297 Fri Jul 31 04:07:30 2020
+++ src/sys/kern/vfs_bio.c Thu Apr 1 06:25:59 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: vfs_bio.c,v 1.297 2020/07/31 04:07:30 chs Exp $ */
+/* $NetBSD: vfs_bio.c,v 1.298 2021/04/01 06:25:59 simonb Exp $ */
/*-
* Copyright (c) 2007, 2008, 2009, 2019, 2020 The NetBSD Foundation, Inc.
@@ -123,7 +123,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_bio.c,v 1.297 2020/07/31 04:07:30 chs Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_bio.c,v 1.298 2021/04/01 06:25:59 simonb Exp $");
#ifdef _KERNEL_OPT
#include "opt_bufcache.h"
@@ -252,6 +252,8 @@ biohist_init(void)
LIST_HEAD(bufhashhdr, buf) *bufhashtbl, invalhash;
u_long bufhash;
+static int bufhash_stats(struct hashstat_sysctl *, bool);
+
static kcondvar_t needbuffer_cv;
/*
@@ -536,6 +538,7 @@ bufinit(void)
sysctl_kern_buf_setup();
sysctl_vm_buf_setup();
+ hashstat_register("bufhash", bufhash_stats);
}
void
@@ -1953,6 +1956,40 @@ sysctl_vm_buf_setup(void)
CTL_VM, CTL_CREATE, CTL_EOL);
}
+static int
+bufhash_stats(struct hashstat_sysctl *hs, bool fill)
+{
+ buf_t *bp;
+ uint64_t chain;
+
+ strlcpy(hs->hash_name, "bufhash", sizeof(hs->hash_name));
+ strlcpy(hs->hash_desc, "buffer hash", sizeof(hs->hash_desc));
+ if (!fill)
+ return 0;
+
+ hs->hash_size = bufhash + 1;
+
+ for (size_t i = 0; i < hs->hash_size; i++) {
+ chain = 0;
+
+ mutex_enter(&bufcache_lock);
+ LIST_FOREACH(bp, &bufhashtbl[i], b_hash) {
+ chain++;
+ }
+ mutex_exit(&bufcache_lock);
+
+ if (chain > 0) {
+ hs->hash_used++;
+ hs->hash_items += chain;
+ if (chain > hs->hash_maxchain)
+ hs->hash_maxchain = chain;
+ }
+ preempt_point();
+ }
+
+ return 0;
+}
+
#ifdef DEBUG
/*
* Print out statistics on the current allocation of the buffer pool.
