Date: 02 Apr 2002 16:45:05 +0200 From: Dag-Erling Smorgrav <des@ofug.org> To: Poul-Henning Kamp <phk@critter.freebsd.dk> Cc: Marcel Moolenaar <marcel@FreeBSD.org>, cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/ia64/ia64 ia64dump.c Message-ID: <xzp7knqupla.fsf@flood.ping.uio.no> In-Reply-To: <51854.1017754714@critter.freebsd.dk> References: <51854.1017754714@critter.freebsd.dk>
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[-- Attachment #1 --]
I *had* patches, but nuked them when you committed your code.
Remnants can be found in the attached garbage file. I even blew a
partition working on this (by setting dumplo too high).
DES
--
Dag-Erling Smorgrav - des@ofug.org
[-- Attachment #2 --]
Index: sys/alpha/alpha/machdep.c
===================================================================
RCS file: /home/ncvs/src/sys/alpha/alpha/machdep.c,v
retrieving revision 1.170
diff -u -r1.170 machdep.c
--- sys/alpha/alpha/machdep.c 27 Mar 2002 09:23:37 -0000 1.170
+++ sys/alpha/alpha/machdep.c 30 Mar 2002 15:05:25 -0000
@@ -192,7 +192,6 @@
struct msgbuf *msgbufp=0;
int Maxmem = 0;
-long dumplo;
int totalphysmem; /* total amount of physical memory in system */
int physmem; /* physical memory used by NetBSD + some rsvd */
Index: sys/conf/options.i386
===================================================================
RCS file: /home/ncvs/src/sys/conf/options.i386,v
retrieving revision 1.169
diff -u -r1.169 options.i386
--- sys/conf/options.i386 27 Feb 2002 09:51:31 -0000 1.169
+++ sys/conf/options.i386 23 Mar 2002 18:04:45 -0000
@@ -188,6 +188,9 @@
# SMB/CIFS filesystem
SMBFS
+# Mutex profiling
+TRACE_MUTEX_TIME opt_global.h
+
# -------------------------------
# EOF
# -------------------------------
Index: sys/i386/i386/machdep.c
===================================================================
RCS file: /home/ncvs/src/sys/i386/i386/machdep.c,v
retrieving revision 1.507
diff -u -r1.507 machdep.c
--- sys/i386/i386/machdep.c 27 Mar 2002 09:23:37 -0000 1.507
+++ sys/i386/i386/machdep.c 30 Mar 2002 15:06:12 -0000
@@ -196,7 +196,6 @@
0, 0, sysctl_hw_availpages, "I", "");
int Maxmem = 0;
-long dumplo;
vm_offset_t phys_avail[10];
Index: sys/ia64/ia64/machdep.c
===================================================================
RCS file: /home/ncvs/src/sys/ia64/ia64/machdep.c,v
retrieving revision 1.85
diff -u -r1.85 machdep.c
--- sys/ia64/ia64/machdep.c 30 Mar 2002 23:25:22 -0000 1.85
+++ sys/ia64/ia64/machdep.c 31 Mar 2002 00:36:27 -0000
@@ -142,7 +142,6 @@
struct msgbuf *msgbufp=0;
int Maxmem = 0;
-long dumplo;
int totalphysmem; /* total amount of physical memory in system */
int physmem; /* physical memory used by NetBSD + some rsvd */
Index: sys/kern/kern_mutex.c
===================================================================
RCS file: /home/ncvs/src/sys/kern/kern_mutex.c,v
retrieving revision 1.83
diff -u -r1.83 kern_mutex.c
--- sys/kern/kern_mutex.c 27 Mar 2002 09:23:38 -0000 1.83
+++ sys/kern/kern_mutex.c 30 Mar 2002 15:06:26 -0000
@@ -37,17 +37,19 @@
#include "opt_ddb.h"
#include <sys/param.h>
+#include <sys/systm.h>
#include <sys/bus.h>
+#include <sys/dump.h>
#include <sys/kernel.h>
+#include <sys/ktr.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/resourcevar.h>
+#include <sys/sbuf.h>
#include <sys/sysctl.h>
-#include <sys/systm.h>
#include <sys/vmmeter.h>
-#include <sys/ktr.h>
#include <machine/atomic.h>
#include <machine/bus.h>
@@ -196,6 +198,104 @@
}
}
+#ifdef TRACE_MUTEX_TIME
+#define TRACE_HASH_SIZE 1009
+SYSCTL_NODE(_kern, OID_AUTO, mtx, CTLFLAG_RD, NULL, "mutex manipulation");
+SYSCTL_NODE(_kern_mtx, OID_AUTO, trace, CTLFLAG_RD, NULL, "mutex tracing");
+static int kern_mtx_trace_enable = 0;
+SYSCTL_INT(_kern_mtx_trace, OID_AUTO, enable, CTLFLAG_RW,
+ &kern_mtx_trace_enable, 0, "Enable tracing of mutex holdtime");
+static int kern_mtx_trace_hashsize = TRACE_HASH_SIZE;
+SYSCTL_INT(_kern_mtx_trace, OID_AUTO, hashsize, CTLFLAG_RD,
+ &kern_mtx_trace_hashsize, 0, "Trace hash size");
+static int kern_mtx_trace_numtraced = 0;
+SYSCTL_INT(_kern_mtx_trace, OID_AUTO, numtraced, CTLFLAG_RD,
+ &kern_mtx_trace_numtraced, 0, "Number of traced mutices");
+static int kern_mtx_trace_collisions = 0;
+SYSCTL_INT(_kern_mtx_trace, OID_AUTO, collisions, CTLFLAG_RD,
+ &kern_mtx_trace_numtraced, 0, "Number of hash collisions");
+
+static struct mutex_trace {
+ char name[64];
+ u_int64_t count;
+ u_int64_t maxtsc;
+ u_int64_t totaltsc;
+ struct mutex_trace *next;
+} *mutex_traces[TRACE_HASH_SIZE];
+
+static struct mtx trace_mtx;
+
+/*
+ * tracebuf is the pool of trace records we have;
+ * we cannot (reliably) handle more than this number
+ * of places in the code where mutexes are aquired.
+ *
+ * We use a static allocation to avoid interacting
+ * with the rest of the system.
+ */
+#define NUM_TRACE_BUFFERS 1000
+static struct mutex_trace tracebuf[NUM_TRACE_BUFFERS];
+static int first_free_mutex_trace = 0;
+
+static const char *unknown = "(unknown)";
+
+/* Number of locks to show in the sysctl. MUST BE AN EVEN NUMBER. */
+#define NUM_LOCKS_TO_DUMP 10
+#define mutex_trace_cmp(a, b) (tracebuf[a].maxtsc - tracebuf[b].maxtsc)
+
+/*
+ * Output statistics of mutex holders that keep the mutex the longest.
+ */
+static int
+dump_mtx_trace(SYSCTL_HANDLER_ARGS)
+{
+ struct sbuf *sb;
+ struct mutex_trace *mtp;
+ int traces[NUM_LOCKS_TO_DUMP];
+ int error, i, j, k;
+
+ if (kern_mtx_trace_numtraced == 0)
+ return SYSCTL_OUT(req, "No locking recorded",
+ sizeof("No locking recorded"));
+
+ /*
+ * Find the 10 largest
+ */
+ mtx_lock_spin(&trace_mtx);
+ for (i = 0; i < NUM_LOCKS_TO_DUMP; ++i)
+ traces[i] = -1;
+ for (k = 0; k < first_free_mutex_trace; ++k) {
+ for (i = 0; i < NUM_LOCKS_TO_DUMP; ++i) {
+ if (traces[i] == -1) {
+ traces[i] = k;
+ break;
+ }
+ if (mutex_trace_cmp(k, traces[i]) < 0)
+ continue;
+ for (j = NUM_LOCKS_TO_DUMP - 1; j > i; --j)
+ traces[j] = traces[j - 1];
+ traces[i] = k;
+ break;
+ }
+ }
+
+ /* Now dump the garbage */
+ sb = sbuf_new(NULL, NULL, 256, SBUF_AUTOEXTEND);
+ for (i = 0; i < NUM_LOCKS_TO_DUMP && traces[i] != -1; ++i) {
+ mtp = &tracebuf[traces[i]];
+ sbuf_printf(sb, "%s: held %llu (%llu)\n",
+ mtp->name, mtp->maxtsc, mtp->totaltsc);
+ }
+ sbuf_finish(sb);
+ mtx_unlock_spin(&trace_mtx);
+ error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb));
+ sbuf_delete(sb);
+ return (error);
+}
+SYSCTL_PROC(_kern_mtx_trace, OID_AUTO, stats, CTLTYPE_STRING|CTLFLAG_RD,
+ NULL, 0, dump_mtx_trace, "A", "Statistics about how long mutexes are held");
+#endif /* TRACE_MUTEX_TIME */
+
/*
* Function versions of the inlined __mtx_* macros. These are used by
* modules and can also be called from assembly language if needed.
@@ -209,6 +309,22 @@
LOCK_LOG_LOCK("LOCK", &m->mtx_object, opts, m->mtx_recurse, file,
line);
WITNESS_LOCK(&m->mtx_object, opts | LOP_EXCLUSIVE, file, line);
+#ifdef TRACE_MUTEX_TIME
+ if (!(trace_mtx.mtx_object.lo_flags & LO_INITIALIZED))
+ mtx_init(&trace_mtx, "mutex trace lock", MTX_SPIN | MTX_QUIET);
+ mtx_lock_spin(&trace_mtx);
+ m->tsc = kern_mtx_trace_enable ? rdtsc() : 0;
+ if (m->name[0] == '\0') {
+ const char *p = file;
+
+ while (p && strncmp(p, "../", 3) == 0)
+ p += 3;
+ if (p == NULL || *p == '\0')
+ p = unknown;
+ snprintf(m->name, sizeof m->name, "%s:%d", p, line);
+ }
+ mtx_unlock_spin(&trace_mtx);
+#endif
}
void
@@ -217,6 +333,54 @@
MPASS(curthread != NULL);
mtx_assert(m, MA_OWNED);
+#ifdef TRACE_MUTEX_TIME
+ if (m->tsc != 0 && m->name[0] != '\0') {
+ struct mutex_trace *trace;
+ u_int64_t tsc, mtsc;
+ u_int hash;
+ char *p;
+
+ tsc = rdtsc();
+ mtsc = m->tsc;
+ m->tsc = 0;
+ if (tsc <= mtsc)
+ goto out;
+ for (hash = 0, p = m->name; *p; p++)
+ hash += (unsigned char)*p;
+ hash %= TRACE_HASH_SIZE;
+ hash = line % TRACE_HASH_SIZE;
+ mtx_lock_spin(&trace_mtx);
+ for (trace = mutex_traces[hash]; trace; trace = trace->next)
+ if (strcmp(trace->name, m->name) == 0)
+ break;
+ if (trace == NULL) {
+ /* Just exit if we cannot get a trace buffer */
+ if (first_free_mutex_trace >= NUM_TRACE_BUFFERS)
+ goto unlock_out;
+ trace = &tracebuf[first_free_mutex_trace++];
+ /* Race protection */
+ if (first_free_mutex_trace > NUM_TRACE_BUFFERS)
+ goto unlock_out;
+ strcpy(trace->name, m->name);
+ if (mutex_traces[hash] != NULL)
+ ++kern_mtx_trace_collisions;
+ trace->next = mutex_traces[hash];
+ mutex_traces[hash] = trace;
+ ++kern_mtx_trace_numtraced;
+ }
+ /*
+ * Record if the mutex has been held longer now than ever
+ * before
+ */
+ if ((tsc - mtsc) > trace->maxtsc)
+ trace->maxtsc = tsc - mtsc;
+ trace->totaltsc += tsc - mtsc;
+ trace->count += 1;
+ unlock_out:
+ mtx_unlock_spin(&trace_mtx);
+ }
+out:
+#endif
WITNESS_UNLOCK(&m->mtx_object, opts | LOP_EXCLUSIVE, file, line);
LOCK_LOG_LOCK("UNLOCK", &m->mtx_object, opts, m->mtx_recurse, file,
line);
Index: sys/kern/kern_shutdown.c
===================================================================
RCS file: /home/ncvs/src/sys/kern/kern_shutdown.c,v
retrieving revision 1.120
diff -u -r1.120 kern_shutdown.c
--- sys/kern/kern_shutdown.c 7 Mar 2002 04:43:51 -0000 1.120
+++ sys/kern/kern_shutdown.c 13 Mar 2002 00:52:56 -0000
@@ -51,6 +51,7 @@
#include <sys/conf.h>
#include <sys/cons.h>
#include <sys/disklabel.h>
+#include <sys/dump.h>
#include <sys/eventhandler.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
@@ -59,9 +60,11 @@
#include <sys/proc.h>
#include <sys/reboot.h>
#include <sys/resourcevar.h>
+#include <sys/sbuf.h>
#include <sys/smp.h> /* smp_active */
#include <sys/sysctl.h>
#include <sys/sysproto.h>
+#include <sys/timetc.h>
#include <sys/vnode.h>
#include <machine/pcb.h>
@@ -116,7 +119,9 @@
*/
const char *panicstr;
-int dumping; /* system is dumping */
+int dumping; /* System is dumping */
+long dumplo; /* Dump offset */
+char dumpinfo[DUMPINFO_SIZE]; /* Dump metadata */
static void boot(int) __dead2;
static void dumpsys(void);
@@ -207,7 +212,7 @@
}
/*
- * Go through the rigmarole of shutting down..
+ * Go through the rigmarole of shutting down..
* this used to be in machdep.c but I'll be dammned if I could see
* anything machine dependant in it.
*/
@@ -444,9 +449,15 @@
if (psize == -1)
return (ENXIO); /* XXX should be ENODEV ? */
/*
- * XXX should clean up checking in dumpsys() to be more like this.
+ * Determine the dump offset. Place it as high as possible on the
+ * dump device, so it will survive a certain amount of swapping
+ * before savecore(1) runs, and reserve enough space for all
+ * physical memory, plus an extra page for metadata.
*/
- newdumplo = psize - Maxmem * (PAGE_SIZE / DEV_BSIZE);
+ /*
+ * XXX what happens if the device's sector size != DEV_BSIZE?
+ */
+ newdumplo = psize - DUMP_SECS(DEV_BSIZE);
if (newdumplo <= LABELSECTOR)
return (ENOSPC);
dumpdev = dev;
@@ -490,6 +501,7 @@
SYSCTL_PROC(_kern, KERN_DUMPDEV, dumpdev, CTLTYPE_OPAQUE|CTLFLAG_RW,
0, sizeof dumpdev, sysctl_kern_dumpdev, "T,dev_t", "");
+extern void *kernbase;
/*
* Doadump comes here after turning off memory management and
@@ -499,7 +511,22 @@
static void
dumpsys(void)
{
- int error;
+ struct sbuf sb;
+ int error;
+
+ sbuf_new(&sb, dumpinfo, DUMPINFO_SIZE, SBUF_FIXEDLEN);
+ /* magic + length of dump metadata */
+ sbuf_printf(&sb, "DUMPINFO 0x%x\n", DUMPINFO_SIZE);
+ sbuf_printf(&sb, "dumpinfo_version=%d\n", DUMPINFO_VERSION);
+ sbuf_printf(&sb, "dumpinfo_size=0x%x\n", DUMPINFO_SIZE);
+ sbuf_printf(&sb, "page_size=0x%x\n", PAGE_SIZE);
+ sbuf_printf(&sb, "dev_bsize=0x%x\n", DEV_BSIZE);
+ sbuf_printf(&sb, "dumplo=0x%lx\n", dumplo);
+ sbuf_printf(&sb, "kernbase=0x%p\n", kernbase);
+ sbuf_printf(&sb, "dumptime=0x%lx\n", timecounter->tc_microtime.tv_sec);
+ sbuf_printf(&sb, "@0x0 0x%x\n", Maxmem);
+ sbuf_finish(&sb);
+ printf(dumpinfo);
savectx(&dumppcb);
if (!dodump)
Index: sys/kern/subr_disk.c
===================================================================
RCS file: /home/ncvs/src/sys/kern/subr_disk.c,v
retrieving revision 1.52
diff -u -r1.52 subr_disk.c
--- sys/kern/subr_disk.c 11 Mar 2002 08:08:02 -0000 1.52
+++ sys/kern/subr_disk.c 15 Mar 2002 20:35:43 -0000
@@ -15,6 +15,7 @@
#include <sys/param.h>
#include <sys/systm.h>
+#include <sys/dump.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <sys/bio.h>
@@ -213,7 +214,7 @@
dl = dsgetlabel(dev, dp->d_slice);
if (!dl)
return (ENXIO);
- *count = Maxmem * (PAGE_SIZE / dl->d_secsize);
+ *count = DUMP_SECS(dl->d_secsize);
if (dumplo <= LABELSECTOR ||
(dumplo + *count > dl->d_partitions[dkpart(dev)].p_size))
return (EINVAL);
Index: sys/kern/subr_witness.c
===================================================================
RCS file: /home/ncvs/src/sys/kern/subr_witness.c,v
retrieving revision 1.103
diff -u -r1.103 subr_witness.c
--- sys/kern/subr_witness.c 27 Mar 2002 09:23:38 -0000 1.103
+++ sys/kern/subr_witness.c 30 Mar 2002 15:06:27 -0000
@@ -214,6 +214,7 @@
{ "ithread table lock", &lock_class_mtx_spin },
{ "sched lock", &lock_class_mtx_spin },
{ "callout", &lock_class_mtx_spin },
+ { "bio queue", &lock_class_mtx_spin },
/*
* leaf locks
*/
Index: sys/pc98/i386/machdep.c
===================================================================
RCS file: /home/ncvs/src/sys/pc98/i386/machdep.c,v
retrieving revision 1.270
diff -u -r1.270 machdep.c
--- sys/pc98/i386/machdep.c 30 Mar 2002 11:14:52 -0000 1.270
+++ sys/pc98/i386/machdep.c 30 Mar 2002 15:07:00 -0000
@@ -209,7 +209,6 @@
#ifdef PC98
int Maxmem_under16M = 0;
#endif
-long dumplo;
vm_offset_t phys_avail[10];
Index: sys/sparc64/sparc64/machdep.c
===================================================================
RCS file: /home/ncvs/src/sys/sparc64/sparc64/machdep.c,v
retrieving revision 1.44
diff -u -r1.44 machdep.c
--- sys/sparc64/sparc64/machdep.c 30 Mar 2002 20:58:08 -0000 1.44
+++ sys/sparc64/sparc64/machdep.c 31 Mar 2002 00:37:10 -0000
@@ -112,7 +112,6 @@
int physmem;
int cold = 1;
-long dumplo;
int Maxmem;
struct mtx Giant;
Index: sys/sys/_mutex.h
===================================================================
RCS file: /home/ncvs/src/sys/sys/_mutex.h,v
retrieving revision 1.4
diff -u -r1.4 _mutex.h
--- sys/sys/_mutex.h 18 Dec 2001 00:27:18 -0000 1.4
+++ sys/sys/_mutex.h 23 Mar 2002 17:41:05 -0000
@@ -41,6 +41,10 @@
volatile u_int mtx_recurse; /* number of recursive holds */
TAILQ_HEAD(, thread) mtx_blocked; /* threads blocked on this lock */
LIST_ENTRY(mtx) mtx_contested; /* list of all contested locks */
+#ifdef TRACE_MUTEX_TIME
+ u_int64_t tsc;
+ char name[64];
+#endif
};
#endif /* !_SYS_MUTEX_TYPES_H_ */
Index: sys/sys/systm.h
===================================================================
RCS file: /home/ncvs/src/sys/sys/systm.h,v
retrieving revision 1.167
diff -u -r1.167 systm.h
--- sys/sys/systm.h 30 Mar 2002 19:58:31 -0000 1.167
+++ sys/sys/systm.h 31 Mar 2002 00:37:12 -0000
@@ -62,9 +62,6 @@
extern int physmem; /* physical memory */
-extern dev_t dumpdev; /* dump device */
-extern long dumplo; /* offset into dumpdev */
-
extern dev_t rootdev; /* root device */
extern dev_t rootdevs[2]; /* possible root devices */
extern char *rootdevnames[2]; /* names of possible root devices */
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