From 01b5ac14024a26f4f1771bc7027e146e86f9c2c3 Mon Sep 17 00:00:00 2001
From: cinap_lenrek <cinap_lenrek@felloff.net>
Date: Sun, 8 Jun 2014 18:54:36 +0200
Subject: [PATCH] iostats: add -C flag to enable mount cache

---
 sys/man/4/iostats             | 11 +++++++++--
 sys/src/cmd/iostats/iostats.c |  8 ++++++--
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/sys/man/4/iostats b/sys/man/4/iostats
index 9472f20b5..cfc77c945 100644
--- a/sys/man/4/iostats
+++ b/sys/man/4/iostats
@@ -5,8 +5,9 @@ iostats \- file system to measure I/O
 .B iostats
 [
 .B -d
-]
-[
+] [
+.B -C
+] [
 .B -f
 .I dbfile
 ]
@@ -55,6 +56,12 @@ is written to
 .I dbfile
 (default
 .BR iostats.out ).
+.PP
+The
+.B -C
+flag sets the MCACHE flag on the mount which allows
+the kernel to cache (see 
+.IR bind(1) ).
 .SH EXAMPLE
 Display summary of file I/O incurred by
 .IR ls (1):
diff --git a/sys/src/cmd/iostats/iostats.c b/sys/src/cmd/iostats/iostats.c
index e65c7c83b..b85e1d75e 100644
--- a/sys/src/cmd/iostats/iostats.c
+++ b/sys/src/cmd/iostats/iostats.c
@@ -48,8 +48,9 @@ main(int argc, char **argv)
 	char *dbfile, *s;
 	char buf[128];
 	float brpsec, bwpsec, bppsec;
-	int type, cpid, fspid, n;
+	int type, cpid, fspid, n, mflag;
 
+	mflag = MREPL;
 	dbfile = DEBUGFILE;
 
 	ARGBEGIN{
@@ -59,6 +60,9 @@ main(int argc, char **argv)
 	case 'f':
 		dbfile = ARGF();
 		break;
+	case 'C':
+		mflag |= MCACHE;
+		break;
 	default:
 		usage();
 	}ARGEND
@@ -83,7 +87,7 @@ main(int argc, char **argv)
 			fatal("no working directory");
 
 		rfork(RFENVG|RFNAMEG|RFNOTEG);
-		if(mount(p[0], -1, "/", MREPL, "") < 0)
+		if(mount(p[0], -1, "/", mflag, "") < 0)
 			fatal("mount /");
 
 		bind("#c/pid", "/dev/pid", MREPL);
-- 
2.44.0