Date: Mon, 28 Apr 2008 18:48:55 -0700 From: Julian Elischer <julian@elischer.org> To: FreeBSD Net <freebsd-net@freebsd.org> Subject: Re: mbuf usage in packets.. Message-ID: <48167E87.40100@elischer.org> In-Reply-To: <48166916.8090801@elischer.org> References: <48166916.8090801@elischer.org>
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Julian Elischer wrote:
>
> I wrote a cruddy little profiler to profile the packets being sent
> on my system..
> after a bit of a live session including things like "ls -lR /usr"
>
[...]
>
> profiling diff attached..
>
slightly imporved version that allows you to clear the stats without
rebooting
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filename="mbprofile.diff"
Index: kern/uipc_mbuf.c
===================================================================
RCS file: /usr/local/cvsroot/freebsd/src/sys/kern/uipc_mbuf.c,v
retrieving revision 1.177
diff -u -r1.177 uipc_mbuf.c
--- kern/uipc_mbuf.c 25 Mar 2008 09:38:59 -0000 1.177
+++ kern/uipc_mbuf.c 29 Apr 2008 01:45:06 -0000
@@ -35,6 +35,7 @@
#include "opt_mac.h"
#include "opt_param.h"
#include "opt_mbuf_stress_test.h"
+#include "opt_mbuf_profiling.h"
#include <sys/param.h>
#include <sys/systm.h>
@@ -1938,3 +1939,139 @@
}
return (m0);
}
+
+#ifdef MBUF_PROFILING
+
+#define MP_BUCKETS 32 /* don't just change this things may overflow.*/
+struct mbufprofile {
+ u_int64_t wasted[MP_BUCKETS];
+ u_int64_t used[MP_BUCKETS];
+ u_int64_t segments[MP_BUCKETS];
+} mbprof;
+
+#define MP_MAXDIGITS 21 /* strlen("16,000,000,000,000,000,000") == 21 */
+#define MP_NUMLINES 6
+#define MP_NUMSPERLINE 16
+#define MP_EXTRABYTES 64 /* > strlen("used:\nwasted:\nsegments:\n") */
+/* work out max space needed and add a bit of spare space too */
+#define MP_MAXLINE ((MP_MAXDIGITS+1) * MP_NUMSPERLINE)
+#define MP_BUFSIZE ((MP_MAXLINE * MP_NUMLINES) + 1 + MP_EXTRABYTES)
+
+char mbprofbuf[MP_BUFSIZE];
+
+void
+m_profile(struct mbuf *m)
+{
+ int segments = 0;
+ int used = 0;
+ int wasted = 0;
+
+ while (m) {
+ segments++;
+ used += m->m_len;
+ if (m->m_flags & M_EXT) {
+ wasted += MHLEN - sizeof(m->m_ext) +
+ m->m_ext.ext_size - m->m_len;
+ } else {
+ if (m->m_flags & M_PKTHDR)
+ wasted += MHLEN - m->m_len;
+ else
+ wasted += MLEN - m->m_len;
+ }
+ m = m->m_next;
+ }
+ /* be paranoid.. it helps */
+ if (segments > MP_BUCKETS - 1)
+ segments = MP_BUCKETS - 1;
+ if (used > 10000000)
+ used = 10000000;
+ if (wasted > 10000000)
+ wasted = 10000000;
+ /* store in the appropriate bucket */
+ /* don't bother locking. if it's slightly off, so what? */
+ mbprof.segments[segments]++;
+ mbprof.used[fls(used)]++;
+ mbprof.wasted[fls(wasted)]++;
+}
+
+static void
+mbprof_textify(void)
+{
+ int offset;
+ char *c;
+ u_int64_t *p;
+
+
+ p = &mbprof.wasted[0];
+ c = mbprofbuf;
+ offset = snprintf(c, MP_MAXLINE + 10,
+ "wasted:\n%lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld\n",
+ p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],
+ p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]);
+ p = &mbprof.wasted[16];
+ c += offset;
+ offset = snprintf(c, MP_MAXLINE,
+ "%lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld\n",
+ p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],
+ p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]);
+ p = &mbprof.used[0];
+ c += offset;
+ offset = snprintf(c, MP_MAXLINE + 10,
+ "used:\n%lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld\n",
+ p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],
+ p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]);
+ p = &mbprof.used[16];
+ c += offset;
+ offset = snprintf(c, MP_MAXLINE,
+ "%lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld\n",
+ p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],
+ p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]);
+ p = &mbprof.segments[0];
+ c += offset;
+ offset = snprintf(c, MP_MAXLINE + 10,
+ "segments:\n%lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld\n",
+ p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],
+ p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]);
+ p = &mbprof.segments[16];
+ c += offset;
+ offset = snprintf(c, MP_MAXLINE,
+ "%lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld\n",
+ p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],
+ p[8], p[9], p[10], p[11], p[12], p[13], p[14], p[15]);
+}
+
+static int
+mbprof_handler(SYSCTL_HANDLER_ARGS)
+{
+ int error;
+
+ mbprof_textify();
+ error = SYSCTL_OUT(req, mbprofbuf, strlen(mbprofbuf) + 1);
+ return (error);
+}
+
+static int
+mbprof_clr_handler(SYSCTL_HANDLER_ARGS)
+{
+ int clear, error;
+
+ clear = 0;
+ error = sysctl_handle_int(oidp, &clear, 0, req);
+ if (error || !req->newptr)
+ return (error);
+
+ if (clear) {
+ bzero(&mbprof, sizeof(mbprof));
+ }
+
+ return (error);
+}
+
+
+SYSCTL_PROC(_kern_ipc, OID_AUTO, mbufprofile, CTLTYPE_STRING|CTLFLAG_RD,
+ NULL, 0, mbprof_handler, "A", "mbuf profiling statistics");
+
+SYSCTL_PROC(_kern_ipc, OID_AUTO, mbufprofileclr, CTLTYPE_INT|CTLFLAG_RW,
+ NULL, 0, mbprof_clr_handler, "I", "clear mbuf profiling statistics");
+#endif
+
Index: sys/mbuf.h
===================================================================
RCS file: /usr/local/cvsroot/freebsd/src/sys/sys/mbuf.h,v
retrieving revision 1.224
diff -u -r1.224 mbuf.h
--- sys/mbuf.h 25 Mar 2008 09:39:02 -0000 1.224
+++ sys/mbuf.h 29 Apr 2008 01:45:06 -0000
@@ -959,4 +959,12 @@
#endif /* _KERNEL */
+#ifdef MBUF_PROFILING
+ void m_profile(struct mbuf *m);
+ #define M_PROFILE(m) m_profile(m)
+#else
+ #define M_PROFILE(m)
+#endif
+
+
#endif /* !_SYS_MBUF_H_ */
Index: net/if_ethersubr.c
===================================================================
RCS file: /usr/local/cvsroot/freebsd/src/sys/net/if_ethersubr.c,v
retrieving revision 1.244
diff -u -r1.244 if_ethersubr.c
--- net/if_ethersubr.c 20 Mar 2008 06:19:34 -0000 1.244
+++ net/if_ethersubr.c 29 Apr 2008 01:45:06 -0000
@@ -37,6 +37,7 @@
#include "opt_mac.h"
#include "opt_netgraph.h"
#include "opt_carp.h"
+#include "opt_mbuf_profiling.h"
#include <sys/param.h>
#include <sys/systm.h>
@@ -162,6 +163,7 @@
senderr(error);
#endif
+ M_PROFILE(m);
if (ifp->if_flags & IFF_MONITOR)
senderr(ENETDOWN);
if (!((ifp->if_flags & IFF_UP) &&
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