Module Name: src
Committed By: riastradh
Date: Thu Feb 20 15:48:38 UTC 2020
Modified Files:
src/sys/kern: vfs_bio.c
Log Message:
Buffer cache SDT probes.
To generate a diff of this commit:
cvs rdiff -u -r1.287 -r1.288 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:1.287 src/sys/kern/vfs_bio.c:1.288
--- src/sys/kern/vfs_bio.c:1.287 Fri Jan 17 19:33:14 2020
+++ src/sys/kern/vfs_bio.c Thu Feb 20 15:48:38 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: vfs_bio.c,v 1.287 2020/01/17 19:33:14 ad Exp $ */
+/* $NetBSD: vfs_bio.c,v 1.288 2020/02/20 15:48:38 riastradh Exp $ */
/*-
* Copyright (c) 2007, 2008, 2009, 2019 The NetBSD Foundation, Inc.
@@ -123,7 +123,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_bio.c,v 1.287 2020/01/17 19:33:14 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_bio.c,v 1.288 2020/02/20 15:48:38 riastradh Exp $");
#ifdef _KERNEL_OPT
#include "opt_bufcache.h"
@@ -154,6 +154,28 @@ __KERNEL_RCSID(0, "$NetBSD: vfs_bio.c,v
#include <miscfs/specfs/specdev.h>
+SDT_PROVIDER_DEFINE(io);
+
+SDT_PROBE_DEFINE4(io, kernel, , bbusy__start,
+ "struct buf *"/*bp*/,
+ "bool"/*intr*/, "int"/*timo*/, "kmutex_t *"/*interlock*/);
+SDT_PROBE_DEFINE5(io, kernel, , bbusy__done,
+ "struct buf *"/*bp*/,
+ "bool"/*intr*/,
+ "int"/*timo*/,
+ "kmutex_t *"/*interlock*/,
+ "int"/*error*/);
+SDT_PROBE_DEFINE0(io, kernel, , getnewbuf__start);
+SDT_PROBE_DEFINE1(io, kernel, , getnewbuf__done, "struct buf *"/*bp*/);
+SDT_PROBE_DEFINE3(io, kernel, , getblk__start,
+ "struct vnode *"/*vp*/, "daddr_t"/*blkno*/, "int"/*size*/);
+SDT_PROBE_DEFINE4(io, kernel, , getblk__done,
+ "struct vnode *"/*vp*/, "daddr_t"/*blkno*/, "int"/*size*/,
+ "struct buf *"/*bp*/);
+SDT_PROBE_DEFINE2(io, kernel, , brelse, "struct buf *"/*bp*/, "int"/*set*/);
+SDT_PROBE_DEFINE1(io, kernel, , wait__start, "struct buf *"/*bp*/);
+SDT_PROBE_DEFINE1(io, kernel, , wait__done, "struct buf *"/*bp*/);
+
#ifndef BUFPAGES
# define BUFPAGES 0
#endif
@@ -1027,6 +1049,8 @@ brelsel(buf_t *bp, int set)
struct bqueue *bufq;
struct vnode *vp;
+ SDT_PROBE2(io, kernel, , brelse, bp, set);
+
KASSERT(bp != NULL);
KASSERT(mutex_owned(&bufcache_lock));
KASSERT(!cv_has_waiters(&bp->b_done));
@@ -1211,6 +1235,7 @@ getblk(struct vnode *vp, daddr_t blkno,
buf_t *bp;
mutex_enter(&bufcache_lock);
+ SDT_PROBE3(io, kernel, , getblk__start, vp, blkno, size);
loop:
bp = incore(vp, blkno);
if (bp != NULL) {
@@ -1219,6 +1244,8 @@ getblk(struct vnode *vp, daddr_t blkno,
if (err == EPASSTHROUGH)
goto loop;
mutex_exit(&bufcache_lock);
+ SDT_PROBE4(io, kernel, , getblk__done,
+ vp, blkno, size, NULL);
return (NULL);
}
KASSERT(!cv_has_waiters(&bp->b_done));
@@ -1260,10 +1287,13 @@ getblk(struct vnode *vp, daddr_t blkno,
LIST_REMOVE(bp, b_hash);
brelsel(bp, BC_INVAL);
mutex_exit(&bufcache_lock);
+ SDT_PROBE4(io, kernel, , getblk__done,
+ vp, blkno, size, NULL);
return NULL;
}
}
BIO_SETPRIO(bp, BPRIO_DEFAULT);
+ SDT_PROBE4(io, kernel, , getblk__done, vp, blkno, size, bp);
return (bp);
}
@@ -1382,6 +1412,8 @@ getnewbuf(int slpflag, int slptimeo, int
struct vnode *vp;
struct mount *transmp = NULL;
+ SDT_PROBE0(io, kernel, , getnewbuf__start);
+
start:
KASSERT(mutex_owned(&bufcache_lock));
@@ -1399,6 +1431,7 @@ getnewbuf(int slpflag, int slptimeo, int
#if defined(DIAGNOSTIC)
bp->b_freelistindex = -1;
#endif /* defined(DIAGNOSTIC) */
+ SDT_PROBE1(io, kernel, , getnewbuf__done, bp);
return (bp);
}
mutex_enter(&bufcache_lock);
@@ -1441,6 +1474,7 @@ getnewbuf(int slpflag, int slptimeo, int
(void)cv_timedwait(&needbuffer_cv,
&bufcache_lock, slptimeo);
}
+ SDT_PROBE1(io, kernel, , getnewbuf__done, NULL);
return (NULL);
}
@@ -1479,6 +1513,7 @@ getnewbuf(int slpflag, int slptimeo, int
KASSERT(transmp != NULL);
fstrans_done(transmp);
mutex_enter(&bufcache_lock);
+ SDT_PROBE1(io, kernel, , getnewbuf__done, NULL);
return (NULL);
}
@@ -1508,6 +1543,7 @@ getnewbuf(int slpflag, int slptimeo, int
mutex_exit(vp->v_interlock);
}
+ SDT_PROBE1(io, kernel, , getnewbuf__done, bp);
return (bp);
}
@@ -1557,11 +1593,6 @@ buf_drain(int n)
return size;
}
-SDT_PROVIDER_DEFINE(io);
-
-SDT_PROBE_DEFINE1(io, kernel, , wait__start, "struct buf *"/*bp*/);
-SDT_PROBE_DEFINE1(io, kernel, , wait__done, "struct buf *"/*bp*/);
-
/*
* Wait for operations on the buffer to complete.
* When they do, extract and return the I/O's error value.
@@ -2163,9 +2194,13 @@ bbusy(buf_t *bp, bool intr, int timo, km
KASSERT(mutex_owned(&bufcache_lock));
+ SDT_PROBE4(io, kernel, , bbusy__start, bp, intr, timo, interlock);
+
if ((bp->b_cflags & BC_BUSY) != 0) {
- if (curlwp == uvm.pagedaemon_lwp)
- return EDEADLK;
+ if (curlwp == uvm.pagedaemon_lwp) {
+ error = EDEADLK;
+ goto out;
+ }
bp->b_cflags |= BC_WANTED;
bref(bp);
if (interlock != NULL)
@@ -2181,11 +2216,15 @@ bbusy(buf_t *bp, bool intr, int timo, km
if (interlock != NULL)
mutex_enter(interlock);
if (error != 0)
- return error;
- return EPASSTHROUGH;
+ goto out;
+ error = EPASSTHROUGH;
+ goto out;
}
bp->b_cflags |= BC_BUSY;
+ error = 0;
+out: SDT_PROBE5(io, kernel, , bbusy__done,
+ bp, intr, timo, interlock, error);
return 0;
}
