From 0faa08a1442b9ebf0082dce5298b2f0a23604ba7 Mon Sep 17 00:00:00 2001
From: Matthew Dillon <dillon@apollo.backplane.com>
Date: Fri, 19 Jun 2009 10:25:12 -0700
Subject: [PATCH] HAMMER UTIL - Add -C cachesize option to improve the 'show'
 command.

* Allows the default in-memory cache size of 16m to be changed.
---
 sbin/hammer/cache.c       |  6 ++++++
 sbin/hammer/hammer.8      |  8 ++++++++
 sbin/hammer/hammer.c      | 24 +++++++++++++++++++++++-
 sbin/hammer/hammer_util.h |  1 +
 4 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/sbin/hammer/cache.c b/sbin/hammer/cache.c
index ee6637bada..1e9892e060 100644
--- a/sbin/hammer/cache.c
+++ b/sbin/hammer/cache.c
@@ -50,6 +50,12 @@ static int CacheMax = 16 * 1024 * 1024;
 static int NCache;
 static TAILQ_HEAD(, cache_info) CacheList = TAILQ_HEAD_INITIALIZER(CacheList);
 
+void
+hammer_cache_set(int bytes)
+{
+	CacheMax = bytes;
+}
+
 void
 hammer_cache_add(struct cache_info *cache, enum cache_type type)
 {
diff --git a/sbin/hammer/hammer.8 b/sbin/hammer/hammer.8
index 45efe14513..ec3ea86868 100644
--- a/sbin/hammer/hammer.8
+++ b/sbin/hammer/hammer.8
@@ -47,6 +47,7 @@
 .\" .Op Fl s Ar linkpath
 .Op Fl i Ar delay
 .Op Fl t Ar seconds
+.Op Fl C Ar cachesize
 .Ar command
 .Op Ar argument ...
 .Sh DESCRIPTION
@@ -123,6 +124,13 @@ Increase verboseness.
 May be specified multiple times.
 .It Fl y
 Force "yes" for any interactive question.
+.It Fl C Ar cachesize
+Set the memory cache size for any raw I/O.  The default is 16m.
+A suffix of 'k' for kilobytes and 'm' for megabytes is allowed,
+else the cache size is specified in bytes.
+.Pp
+This option is typically only used with diagnostic commands
+as kernel-supported commands will use the kernel's buffer cache.
 .El
 .Pp
 The commands are as follows:
diff --git a/sbin/hammer/hammer.c b/sbin/hammer/hammer.c
index fa127c8ba5..8b7e1d7b45 100644
--- a/sbin/hammer/hammer.c
+++ b/sbin/hammer/hammer.c
@@ -64,8 +64,9 @@ main(int ac, char **av)
 	char *ptr;
 	u_int32_t status;
 	int ch;
+	int cacheSize = 0;
 
-	while ((ch = getopt(ac, av, "b:c:dhf:i:qrs:t:v2y")) != -1) {
+	while ((ch = getopt(ac, av, "b:c:dhf:i:qrs:t:v2yC:")) != -1) {
 		switch(ch) {
 		case '2':
 			TwoWayPipeOpt = 1;
@@ -131,6 +132,27 @@ main(int ac, char **av)
 			else
 				++QuietOpt;
 			break;
+		case 'C':
+			cacheSize = strtol(optarg, &ptr, 0);
+			switch(*ptr) {
+			case 'm':
+			case 'M':
+				cacheSize *= 1024;
+				/* fall through */
+			case 'k':
+			case 'K':
+				cacheSize *= 1024;
+				break;
+			case '\0':
+				/* bytes if no suffix */
+				break;
+			default:
+				usage(1);
+			}
+			if (cacheSize < 1024 * 1024)
+				cacheSize = 1024 * 1024;
+			hammer_cache_set(cacheSize);
+			break;
 		default:
 			usage(1);
 			/* not reached */
diff --git a/sbin/hammer/hammer_util.h b/sbin/hammer/hammer_util.h
index f5499e80ac..b4c767bebf 100644
--- a/sbin/hammer/hammer_util.h
+++ b/sbin/hammer/hammer_util.h
@@ -143,6 +143,7 @@ void flush_all_volumes(void);
 void flush_volume(struct volume_info *vol);
 void flush_buffer(struct buffer_info *buf);
 
+void hammer_cache_set(int bytes);
 void hammer_cache_add(struct cache_info *cache, enum cache_type type);
 void hammer_cache_del(struct cache_info *cache);
 void hammer_cache_flush(void);
-- 
2.41.0