The next 8 patches change the following files :
arch/alpha/oprofile/Makefile | 3 +
arch/alpha/oprofile/common.c | 2 -
arch/i386/oprofile/Makefile | 5 +-
arch/i386/oprofile/init.c | 11 ++----
arch/i386/oprofile/nmi_int.c | 14 +++----
arch/i386/oprofile/timer_int.c | 58
--------------------------------
arch/parisc/oprofile/Makefile | 5 +-
arch/parisc/oprofile/init.c | 3 -
arch/parisc/oprofile/timer_int.c | 58
--------------------------------
arch/ppc64/oprofile/Makefile | 5 +-
arch/ppc64/oprofile/init.c | 3 -
arch/ppc64/oprofile/timer_int.c | 59
---------------------------------
arch/sparc64/oprofile/Makefile | 5 +-
arch/sparc64/oprofile/init.c | 3 -
arch/sparc64/oprofile/timer_int.c | 59
---------------------------------
arch/x86_64/oprofile/Makefile | 9 ++---
drivers/oprofile/buffer_sync.c | 67
+++++++++++++++++++++++++-------------
drivers/oprofile/event_buffer.c | 6 ++-
drivers/oprofile/oprof.c | 23 +++++++++----
drivers/oprofile/oprofile_stats.c | 6 +--
drivers/oprofile/oprofile_stats.h | 2 -
drivers/oprofile/timer_int.c | 56
+++++++++++++++++++++++++++++++
22 files changed, 159 insertions(+), 303 deletions(-)
Convention is that error returns are negative.
diff -Naur -X dontdiff linux-cvs/arch/alpha/oprofile/common.c linux-me/arch/alpha/oprofile/common.c
--- linux-cvs/arch/alpha/oprofile/common.c 2003-04-05 18:44:20.000000000 +0100
+++ linux-me/arch/alpha/oprofile/common.c 2003-04-29 01:18:48.000000000 +0100
@@ -175,7 +175,7 @@
}
if (!lmodel)
- return ENODEV;
+ return -ENODEV;
model = lmodel;
oprof_axp_ops.cpu_type = lmodel->cpu_type;
Schedule work away on an unmap, instead of calling it directly. Should result
in less lost samples, and it fixes a lock ordering problem buffer_sem <-> mmap_sem
diff -Naur -X dontdiff linux-cvs/drivers/oprofile/buffer_sync.c linux-me/drivers/oprofile/buffer_sync.c
--- linux-cvs/drivers/oprofile/buffer_sync.c 2003-04-05 18:44:49.000000000 +0100
+++ linux-me/drivers/oprofile/buffer_sync.c 2003-05-03 20:10:44.000000000 +0100
@@ -58,8 +58,8 @@
* must concern ourselves with. First, when a task is about to
* exit (exit_mmap()), we should process the buffer to deal with
* any samples in the CPU buffer, before we lose the ->mmap information
- * we need. Second, a task may unmap (part of) an executable mmap,
- * so we want to process samples before that happens too
+ * we need. It is vital to get this case correct, otherwise we can
+ * end up trying to access a freed task_struct.
*/
static int mm_notify(struct notifier_block * self, unsigned long val, void * data)
{
@@ -67,6 +67,29 @@
return 0;
}
+
+/* Second, a task may unmap (part of) an executable mmap,
+ * so we want to process samples before that happens too. This is merely
+ * a QOI issue not a correctness one.
+ */
+static int munmap_notify(struct notifier_block * self, unsigned long val, void * data)
+{
+ /* Note that we cannot sync the buffers directly, because we might end up
+ * taking the the mmap_sem that we hold now inside of event_buffer_read()
+ * on a page fault, whilst holding buffer_sem - deadlock.
+ *
+ * This would mean a threaded reader of the event buffer, but we should
+ * prevent it anyway.
+ *
+ * Delaying the work in a context that doesn't hold the mmap_sem means
+ * that we won't lose samples from other mappings that current() may
+ * have. Note that either way, we lose any pending samples for what is
+ * being unmapped.
+ */
+ schedule_work(&sync_wq);
+ return 0;
+}
+
/* We need to be told about new modules so we don't attribute to a previously
* loaded module, or drop the samples on the floor.
@@ -92,7 +115,7 @@
};
static struct notifier_block exec_unmap_nb = {
- .notifier_call = mm_notify,
+ .notifier_call = munmap_notify,
};
static struct notifier_block exit_mmap_nb = {
Consolidate all the arch copies of timer_int.c into one place. Also fixes
a problem with PA-RISC not using instruction_pointer() when it should.
diff -Naur -X dontdiff linux-cvs/arch/alpha/oprofile/Makefile linux-me/arch/alpha/oprofile/Makefile
--- linux-cvs/arch/alpha/oprofile/Makefile 2003-02-23 18:27:21.000000000 +0000
+++ linux-me/arch/alpha/oprofile/Makefile 2003-04-29 01:17:51.000000000 +0100
@@ -5,7 +5,8 @@
DRIVER_OBJS = $(addprefix ../../../drivers/oprofile/, \
oprof.o cpu_buffer.o buffer_sync.o \
event_buffer.o oprofile_files.o \
- oprofilefs.o oprofile_stats.o )
+ oprofilefs.o oprofile_stats.o \
+ timer_int.o )
oprofile-y := $(DRIVER_OBJS) common.o
oprofile-$(CONFIG_ALPHA_GENERIC) += op_model_ev4.o \
diff -Naur -X dontdiff linux-cvs/arch/i386/oprofile/init.c linux-me/arch/i386/oprofile/init.c
--- linux-cvs/arch/i386/oprofile/init.c 2003-04-05 18:44:23.000000000 +0100
+++ linux-me/arch/i386/oprofile/init.c 2003-04-29 01:17:00.000000000 +0100
@@ -11,22 +11,19 @@
#include <linux/init.h>
/* We support CPUs that have performance counters like the Pentium Pro
- * with NMI mode samples. Other x86 CPUs use a simple interrupt keyed
- * off the timer interrupt, which cannot profile interrupts-disabled
- * code unlike the NMI-based code.
+ * with the NMI mode driver.
*/
extern int nmi_init(struct oprofile_operations ** ops);
extern void nmi_exit(void);
-extern void timer_init(struct oprofile_operations ** ops);
int __init oprofile_arch_init(struct oprofile_operations ** ops)
{
#ifdef CONFIG_X86_LOCAL_APIC
- if (!nmi_init(ops))
+ return nmi_init(ops);
+#else
+ return -ENODEV;
#endif
- timer_init(ops);
- return 0;
}
diff -Naur -X dontdiff linux-cvs/arch/i386/oprofile/Makefile linux-me/arch/i386/oprofile/Makefile
--- linux-cvs/arch/i386/oprofile/Makefile 2003-02-11 20:25:24.000000000 +0000
+++ linux-me/arch/i386/oprofile/Makefile 2003-04-29 01:11:32.000000000 +0100
@@ -3,8 +3,9 @@
DRIVER_OBJS = $(addprefix ../../../drivers/oprofile/, \
oprof.o cpu_buffer.o buffer_sync.o \
event_buffer.o oprofile_files.o \
- oprofilefs.o oprofile_stats.o )
+ oprofilefs.o oprofile_stats.o \
+ timer_int.o )
-oprofile-y := $(DRIVER_OBJS) init.o timer_int.o
+oprofile-y := $(DRIVER_OBJS) init.o
oprofile-$(CONFIG_X86_LOCAL_APIC) += nmi_int.o op_model_athlon.o \
op_model_ppro.o op_model_p4.o
diff -Naur -X dontdiff linux-cvs/arch/i386/oprofile/nmi_int.c linux-me/arch/i386/oprofile/nmi_int.c
--- linux-cvs/arch/i386/oprofile/nmi_int.c 2003-04-05 18:44:23.000000000 +0100
+++ linux-me/arch/i386/oprofile/nmi_int.c 2003-04-29 01:16:50.000000000 +0100
@@ -314,13 +314,13 @@
__u8 family = current_cpu_data.x86;
if (!cpu_has_apic)
- return 0;
+ return -ENODEV;
switch (vendor) {
case X86_VENDOR_AMD:
/* Needs to be at least an Athlon (or hammer in 32bit mode) */
if (family < 6)
- return 0;
+ return -ENODEV;
model = &op_athlon_spec;
nmi_ops.cpu_type = "i386/athlon";
break;
@@ -331,30 +331,30 @@
/* Pentium IV */
case 0xf:
if (!p4_init())
- return 0;
+ return -ENODEV;
break;
/* A P6-class processor */
case 6:
if (!ppro_init())
- return 0;
+ return -ENODEV;
break;
default:
- return 0;
+ return -ENODEV;
}
break;
#endif /* !CONFIG_X86_64 */
default:
- return 0;
+ return -ENODEV;
}
init_driverfs();
using_nmi = 1;
*ops = &nmi_ops;
printk(KERN_INFO "oprofile: using NMI interrupt.\n");
- return 1;
+ return 0;
}
diff -Naur -X dontdiff linux-cvs/arch/i386/oprofile/timer_int.c linux-me/arch/i386/oprofile/timer_int.c
--- linux-cvs/arch/i386/oprofile/timer_int.c 2003-02-11 20:26:06.000000000 +0000
+++ linux-me/arch/i386/oprofile/timer_int.c 1970-01-01 01:00:00.000000000 +0100
@@ -1,58 +0,0 @@
-/**
- * @file timer_int.c
- *
- * @remark Copyright 2002 OProfile authors
- * @remark Read the file COPYING
- *
- * @author John Levon <[email protected]>
- */
-
-#include <linux/kernel.h>
-#include <linux/notifier.h>
-#include <linux/smp.h>
-#include <linux/irq.h>
-#include <linux/oprofile.h>
-#include <asm/ptrace.h>
-
-#include "op_counter.h"
-
-static int timer_notify(struct notifier_block * self, unsigned long val, void * data)
-{
- struct pt_regs * regs = (struct pt_regs *)data;
- int cpu = smp_processor_id();
- unsigned long eip = instruction_pointer(regs);
-
- oprofile_add_sample(eip, !user_mode(regs), 0, cpu);
- return 0;
-}
-
-
-static struct notifier_block timer_notifier = {
- .notifier_call = timer_notify,
-};
-
-
-static int timer_start(void)
-{
- return register_profile_notifier(&timer_notifier);
-}
-
-
-static void timer_stop(void)
-{
- unregister_profile_notifier(&timer_notifier);
-}
-
-
-static struct oprofile_operations timer_ops = {
- .start = timer_start,
- .stop = timer_stop,
- .cpu_type = "timer"
-};
-
-
-void __init timer_init(struct oprofile_operations ** ops)
-{
- *ops = &timer_ops;
- printk(KERN_INFO "oprofile: using timer interrupt.\n");
-}
diff -Naur -X dontdiff linux-cvs/arch/parisc/oprofile/init.c linux-me/arch/parisc/oprofile/init.c
--- linux-cvs/arch/parisc/oprofile/init.c 2003-04-05 18:44:29.000000000 +0100
+++ linux-me/arch/parisc/oprofile/init.c 2003-04-29 01:24:09.000000000 +0100
@@ -15,8 +15,7 @@
int __init oprofile_arch_init(struct oprofile_operations ** ops)
{
- timer_init(ops);
- return 0;
+ return -ENODEV;
}
diff -Naur -X dontdiff linux-cvs/arch/parisc/oprofile/Makefile linux-me/arch/parisc/oprofile/Makefile
--- linux-cvs/arch/parisc/oprofile/Makefile 2003-01-13 21:24:33.000000000 +0000
+++ linux-me/arch/parisc/oprofile/Makefile 2003-04-29 01:24:18.000000000 +0100
@@ -3,6 +3,7 @@
DRIVER_OBJS = $(addprefix ../../../drivers/oprofile/, \
oprof.o cpu_buffer.o buffer_sync.o \
event_buffer.o oprofile_files.o \
- oprofilefs.o oprofile_stats.o )
+ oprofilefs.o oprofile_stats.o \
+ timer_int.o )
-oprofile-y := $(DRIVER_OBJS) init.o timer_int.o
+oprofile-y := $(DRIVER_OBJS) init.o
diff -Naur -X dontdiff linux-cvs/arch/parisc/oprofile/timer_int.c linux-me/arch/parisc/oprofile/timer_int.c
--- linux-cvs/arch/parisc/oprofile/timer_int.c 2003-02-11 20:26:06.000000000 +0000
+++ linux-me/arch/parisc/oprofile/timer_int.c 1970-01-01 01:00:00.000000000 +0100
@@ -1,58 +0,0 @@
-/**
- * @file timer_int.c
- *
- * @remark Copyright 2002 OProfile authors
- * @remark Read the file COPYING
- *
- * @author John Levon <[email protected]>
- */
-
-#include <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/notifier.h>
-#include <linux/smp.h>
-#include <linux/irq.h>
-#include <linux/oprofile.h>
-#include <asm/ptrace.h>
-
-static int timer_notify(struct notifier_block * self, unsigned long val, void * data)
-{
- struct pt_regs * regs = (struct pt_regs *)data;
- int cpu = smp_processor_id();
- unsigned long pc = regs->iaoq[0];
- int is_kernel = !user_mode(regs);
-
- oprofile_add_sample(pc, is_kernel, 0, cpu);
- return 0;
-}
-
-
-static struct notifier_block timer_notifier = {
- .notifier_call = timer_notify,
-};
-
-
-static int timer_start(void)
-{
- return register_profile_notifier(&timer_notifier);
-}
-
-
-static void timer_stop(void)
-{
- unregister_profile_notifier(&timer_notifier);
-}
-
-
-static struct oprofile_operations timer_ops = {
- .start = timer_start,
- .stop = timer_stop,
- .cpu_type = "timer"
-};
-
-
-void __init timer_init(struct oprofile_operations ** ops)
-{
- *ops = &timer_ops;
- printk(KERN_INFO "oprofile: using timer interrupt.\n");
-}
diff -Naur -X dontdiff linux-cvs/arch/ppc64/oprofile/init.c linux-me/arch/ppc64/oprofile/init.c
--- linux-cvs/arch/ppc64/oprofile/init.c 2003-04-05 18:44:32.000000000 +0100
+++ linux-me/arch/ppc64/oprofile/init.c 2003-04-29 01:23:33.000000000 +0100
@@ -15,8 +15,7 @@
int __init oprofile_arch_init(struct oprofile_operations ** ops)
{
- timer_init(ops);
- return 0;
+ return -ENODEV;
}
diff -Naur -X dontdiff linux-cvs/arch/ppc64/oprofile/Makefile linux-me/arch/ppc64/oprofile/Makefile
--- linux-cvs/arch/ppc64/oprofile/Makefile 2003-01-02 19:32:40.000000000 +0000
+++ linux-me/arch/ppc64/oprofile/Makefile 2003-04-29 01:24:29.000000000 +0100
@@ -3,6 +3,7 @@
DRIVER_OBJS := $(addprefix ../../../drivers/oprofile/, \
oprof.o cpu_buffer.o buffer_sync.o \
event_buffer.o oprofile_files.o \
- oprofilefs.o oprofile_stats.o )
+ oprofilefs.o oprofile_stats.o \
+ timer_int.o )
-oprofile-y := $(DRIVER_OBJS) init.o timer_int.o
+oprofile-y := $(DRIVER_OBJS) init.o
diff -Naur -X dontdiff linux-cvs/arch/ppc64/oprofile/timer_int.c linux-me/arch/ppc64/oprofile/timer_int.c
--- linux-cvs/arch/ppc64/oprofile/timer_int.c 2003-02-22 07:55:49.000000000 +0000
+++ linux-me/arch/ppc64/oprofile/timer_int.c 1970-01-01 01:00:00.000000000 +0100
@@ -1,59 +0,0 @@
-/**
- * @file timer_int.c
- *
- * @remark Copyright 2002 OProfile authors
- * @remark Read the file COPYING
- *
- * @author John Levon <[email protected]>
- */
-
-#include <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/notifier.h>
-#include <linux/smp.h>
-#include <linux/irq.h>
-#include <linux/oprofile.h>
-#include <linux/profile.h>
-#include <asm/ptrace.h>
-
-static int timer_notify(struct notifier_block * self, unsigned long val, void * data)
-{
- struct pt_regs * regs = (struct pt_regs *)data;
- int cpu = smp_processor_id();
- unsigned long pc = instruction_pointer(regs);
- int is_kernel = !user_mode(regs);
-
- oprofile_add_sample(pc, is_kernel, 0, cpu);
- return 0;
-}
-
-
-static struct notifier_block timer_notifier = {
- .notifier_call = timer_notify,
-};
-
-
-static int timer_start(void)
-{
- return register_profile_notifier(&timer_notifier);
-}
-
-
-static void timer_stop(void)
-{
- unregister_profile_notifier(&timer_notifier);
-}
-
-
-static struct oprofile_operations timer_ops = {
- .start = timer_start,
- .stop = timer_stop,
- .cpu_type = "timer"
-};
-
-
-void __init timer_init(struct oprofile_operations ** ops)
-{
- *ops = &timer_ops;
- printk(KERN_INFO "oprofile: using timer interrupt.\n");
-}
diff -Naur -X dontdiff linux-cvs/arch/sparc64/oprofile/init.c linux-me/arch/sparc64/oprofile/init.c
--- linux-cvs/arch/sparc64/oprofile/init.c 2003-04-05 18:44:34.000000000 +0100
+++ linux-me/arch/sparc64/oprofile/init.c 2003-04-29 01:23:09.000000000 +0100
@@ -15,8 +15,7 @@
int __init oprofile_arch_init(struct oprofile_operations ** ops)
{
- timer_init(ops);
- return 0;
+ return -ENODEV;
}
diff -Naur -X dontdiff linux-cvs/arch/sparc64/oprofile/Makefile linux-me/arch/sparc64/oprofile/Makefile
--- linux-cvs/arch/sparc64/oprofile/Makefile 2002-12-09 01:58:08.000000000 +0000
+++ linux-me/arch/sparc64/oprofile/Makefile 2003-04-29 01:20:27.000000000 +0100
@@ -3,6 +3,7 @@
DRIVER_OBJS = $(addprefix ../../../drivers/oprofile/, \
oprof.o cpu_buffer.o buffer_sync.o \
event_buffer.o oprofile_files.o \
- oprofilefs.o oprofile_stats.o )
+ oprofilefs.o oprofile_stats.o \
+ timer_int.o )
-oprofile-y := $(DRIVER_OBJS) init.o timer_int.o
+oprofile-y := $(DRIVER_OBJS) init.o
diff -Naur -X dontdiff linux-cvs/arch/sparc64/oprofile/timer_int.c linux-me/arch/sparc64/oprofile/timer_int.c
--- linux-cvs/arch/sparc64/oprofile/timer_int.c 2003-02-20 01:03:34.000000000 +0000
+++ linux-me/arch/sparc64/oprofile/timer_int.c 1970-01-01 01:00:00.000000000 +0100
@@ -1,59 +0,0 @@
-/**
- * @file timer_int.c
- *
- * @remark Copyright 2002 OProfile authors
- * @remark Read the file COPYING
- *
- * @author John Levon <[email protected]>
- */
-
-#include <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/notifier.h>
-#include <linux/smp.h>
-#include <linux/irq.h>
-#include <linux/oprofile.h>
-#include <linux/profile.h>
-#include <asm/ptrace.h>
-
-static int timer_notify(struct notifier_block * self, unsigned long val, void * data)
-{
- struct pt_regs * regs = (struct pt_regs *)data;
- int cpu = smp_processor_id();
- unsigned long pc = instruction_pointer(regs);
- int is_kernel = !user_mode(regs);
-
- oprofile_add_sample(pc, is_kernel, 0, cpu);
- return 0;
-}
-
-
-static struct notifier_block timer_notifier = {
- .notifier_call = timer_notify,
-};
-
-
-static int timer_start(void)
-{
- return register_profile_notifier(&timer_notifier);
-}
-
-
-static void timer_stop(void)
-{
- unregister_profile_notifier(&timer_notifier);
-}
-
-
-static struct oprofile_operations timer_ops = {
- .start = timer_start,
- .stop = timer_stop,
- .cpu_type = "timer"
-};
-
-
-void __init timer_init(struct oprofile_operations ** ops)
-{
- *ops = &timer_ops;
- printk(KERN_INFO "oprofile: using timer interrupt.\n");
-}
diff -Naur -X dontdiff linux-cvs/arch/x86_64/oprofile/Makefile linux-me/arch/x86_64/oprofile/Makefile
--- linux-cvs/arch/x86_64/oprofile/Makefile 2002-12-28 19:54:15.000000000 +0000
+++ linux-me/arch/x86_64/oprofile/Makefile 2003-04-29 01:19:24.000000000 +0100
@@ -9,9 +9,10 @@
DRIVER_OBJS = $(addprefix ../../../drivers/oprofile/, \
oprof.o cpu_buffer.o buffer_sync.o \
event_buffer.o oprofile_files.o \
- oprofilefs.o oprofile_stats.o )
+ oprofilefs.o oprofile_stats.o \
+ timer_int.o )
-oprofile-objs := $(DRIVER_OBJS) init.o timer_int.o
+oprofile-objs := $(DRIVER_OBJS) init.o
oprofile-$(CONFIG_X86_LOCAL_APIC) += nmi_int.o op_model_athlon.o
@@ -23,11 +24,9 @@
@ln -sf ../../i386/oprofile/op_model_athlon.c $(obj)/op_model_athlon.c
$(obj)/init.c: ${INCL}
@ln -sf ../../i386/oprofile/init.c $(obj)/init.c
-$(obj)/timer_int.c: ${INCL}
- @ln -sf ../../i386/oprofile/timer_int.c $(obj)/timer_int.c
$(obj)/op_counter.h:
@ln -sf ../../i386/oprofile/op_counter.h $(obj)/op_counter.h
$(obj)/op_x86_model.h:
@ln -sf ../../i386/oprofile/op_x86_model.h $(obj)/op_x86_model.h
-clean-files += op_x86_model.h op_counter.h timer_int.c init.c \
+clean-files += op_x86_model.h op_counter.h init.c \
op_model_athlon.c nmi_int.c
diff -Naur -X dontdiff linux-cvs/drivers/oprofile/timer_int.c linux-me/drivers/oprofile/timer_int.c
--- linux-cvs/drivers/oprofile/timer_int.c 1970-01-01 01:00:00.000000000 +0100
+++ linux-me/drivers/oprofile/timer_int.c 2003-04-29 01:25:24.000000000 +0100
@@ -0,0 +1,56 @@
+/**
+ * @file timer_int.c
+ *
+ * @remark Copyright 2002 OProfile authors
+ * @remark Read the file COPYING
+ *
+ * @author John Levon <[email protected]>
+ */
+
+#include <linux/kernel.h>
+#include <linux/notifier.h>
+#include <linux/smp.h>
+#include <linux/irq.h>
+#include <linux/oprofile.h>
+#include <asm/ptrace.h>
+
+static int timer_notify(struct notifier_block * self, unsigned long val, void * data)
+{
+ struct pt_regs * regs = (struct pt_regs *)data;
+ int cpu = smp_processor_id();
+ unsigned long eip = instruction_pointer(regs);
+
+ oprofile_add_sample(eip, !user_mode(regs), 0, cpu);
+ return 0;
+}
+
+
+static struct notifier_block timer_notifier = {
+ .notifier_call = timer_notify,
+};
+
+
+static int timer_start(void)
+{
+ return register_profile_notifier(&timer_notifier);
+}
+
+
+static void timer_stop(void)
+{
+ unregister_profile_notifier(&timer_notifier);
+}
+
+
+static struct oprofile_operations timer_ops = {
+ .start = timer_start,
+ .stop = timer_stop,
+ .cpu_type = "timer"
+};
+
+
+void __init timer_init(struct oprofile_operations ** ops)
+{
+ *ops = &timer_ops;
+ printk(KERN_INFO "oprofile: using timer interrupt.\n");
+}
diff -Naur -X dontdiff linux-cvs/drivers/oprofile/oprof.c linux-me/drivers/oprofile/oprof.c
--- linux-cvs/drivers/oprofile/oprof.c 2003-04-05 18:44:50.000000000 +0100
+++ linux-me/drivers/oprofile/oprof.c 2003-04-30 19:58:07.000000000 +0100
@@ -119,14 +119,23 @@
}
+extern void timer_init(struct oprofile_operations ** ops);
+
+
static int __init oprofile_init(void)
{
int err;
/* Architecture must fill in the interrupt ops and the
- * logical CPU type.
+ * logical CPU type, or we can fall back to the timer
+ * interrupt profiler.
*/
err = oprofile_arch_init(&oprofile_ops);
+ if (err == -ENODEV) {
+ timer_init(&oprofile_ops);
+ err = 0;
+ }
+
if (err)
goto out;
Clear up the code around start_sem so it's more obvious, and remove a pointless
down/up pair on buffer_sem (shutdown is already synchronised in sync_stop()).
diff -Naur -X dontdiff linux-cvs/drivers/oprofile/oprof.c linux-me/drivers/oprofile/oprof.c
--- linux/drivers/oprofile/oprof.c 2003-04-30 19:58:07.000000000 +0100
+++ linux-me/drivers/oprofile/oprof.c 2003-04-29 01:16:00.000000000 +0100
@@ -28,6 +28,8 @@
{
int err;
+ down(&start_sem);
+
if ((err = alloc_cpu_buffers()))
goto out;
@@ -45,7 +47,6 @@
if ((err = sync_start()))
goto out3;
- down(&start_sem);
is_setup = 1;
up(&start_sem);
return 0;
@@ -58,6 +59,7 @@
out1:
free_cpu_buffers();
out:
+ up(&start_sem);
return err;
}
@@ -106,22 +108,20 @@
void oprofile_shutdown(void)
{
+ down(&start_sem);
sync_stop();
if (oprofile_ops->shutdown)
oprofile_ops->shutdown();
- /* down() is also necessary to synchronise all pending events
- * before freeing */
- down(&buffer_sem);
is_setup = 0;
- up(&buffer_sem);
free_event_buffer();
free_cpu_buffers();
+ up(&start_sem);
}
-
+
extern void timer_init(struct oprofile_operations ** ops);
-
+
static int __init oprofile_init(void)
{
int err;
Now we don't do buffer syncs whilst holding current's mmap_sem ever,
we can wait to hold it. Also take task_lock and try to improve the docs a bit.
diff -Naur -X dontdiff linux-cvs/drivers/oprofile/buffer_sync.c linux-me/drivers/oprofile/buffer_sync.c
--- linux-cvs/drivers/oprofile/buffer_sync.c 2003-04-05 18:44:49.000000000 +0100
+++ linux-me/drivers/oprofile/buffer_sync.c 2003-05-03 20:10:44.000000000 +0100
@@ -310,26 +337,23 @@
/* Take the task's mmap_sem to protect ourselves from
* races when we do lookup_dcookie().
*/
-static struct mm_struct * take_task_mm(struct task_struct * task)
+static struct mm_struct * take_tasks_mm(struct task_struct * task)
{
- struct mm_struct * mm = task->mm;
-
- /* if task->mm !NULL, mm_count must be at least 1. It cannot
- * drop to 0 without the task exiting, which will have to sleep
- * on buffer_sem first. So we do not need to mark mm_count
- * ourselves.
+ struct mm_struct * mm;
+
+ /* Subtle. We don't need to keep a reference to this task's mm,
+ * because, for the mm to be freed on another CPU, that would have
+ * to go through the task exit notifier, which ends up sleeping
+ * on the buffer_sem we hold, so we end up with mutual exclusion
+ * anyway.
*/
+ task_lock(task);
+ mm = task->mm;
+ task_unlock(task);
+
if (mm) {
- /* More ugliness. If a task took its mmap
- * sem then came to sleep on buffer_sem we
- * will deadlock waiting for it. So we can
- * but try. This will lose samples :/
- */
- if (!down_read_trylock(&mm->mmap_sem)) {
- /* FIXME: this underestimates samples lost */
- atomic_inc(&oprofile_stats.sample_lost_mmap_sem);
- mm = NULL;
- }
+ /* needed to walk the task's VMAs */
+ down_read(&mm->mmap_sem);
}
return mm;
@@ -399,7 +423,7 @@
new = (struct task_struct *)s->event;
release_mm(mm);
- mm = take_task_mm(new);
+ mm = take_tasks_mm(new);
cookie = get_exec_dcookie(mm);
add_user_ctx_switch(new->pid, cookie);
@@ -460,4 +484,3 @@
schedule_work(&sync_wq);
/* timer is re-added by the scheduled task */
}
-
If there's are multiple tasks sleeping inside the read routine ever, this is necessary.
diff -Naur -X dontdiff linux-cvs/drivers/oprofile/event_buffer.c linux-me/drivers/oprofile/event_buffer.c
--- linux-cvs/drivers/oprofile/event_buffer.c 2002-12-21 19:18:20.000000000 +0000
+++ linux-me/drivers/oprofile/event_buffer.c 2003-04-29 01:09:35.000000000 +0100
@@ -151,11 +151,15 @@
if (count != max || *offset)
return -EINVAL;
- /* wait for the event buffer to fill up with some data */
wait_event_interruptible(buffer_wait, atomic_read(&buffer_ready));
+
if (signal_pending(current))
return -EINTR;
+ /* can't currently happen */
+ if (!atomic_read(&buffer_ready))
+ return -EAGAIN;
+
down(&buffer_sem);
atomic_set(&buffer_ready, 0);
Change the lost_mmap_sem stat to lost_no_mm, and account it.
diff -Naur -X dontdiff linux-cvs/drivers/oprofile/buffer_sync.c linux-me/drivers/oprofile/buffer_sync.c
--- linux-cvs/drivers/oprofile/buffer_sync.c 2003-04-05 18:44:49.000000000 +0100
+++ linux-me/drivers/oprofile/buffer_sync.c 2003-05-03 20:10:44.000000000 +0100
@@ -296,6 +321,8 @@
add_sample_entry(s->eip, s->event);
} else if (mm) {
add_us_sample(mm, s);
+ } else {
+ atomic_inc(&oprofile_stats.sample_lost_no_mm);
}
}
diff -Naur -X dontdiff linux-cvs/drivers/oprofile/oprofile_stats.c linux-me/drivers/oprofile/oprofile_stats.c
--- linux-cvs/drivers/oprofile/oprofile_stats.c 2003-03-07 15:39:16.000000000 +0000
+++ linux-me/drivers/oprofile/oprofile_stats.c 2003-05-01 14:40:18.000000000 +0100
@@ -31,7 +31,7 @@
cpu_buf->sample_lost_task_exit = 0;
}
- atomic_set(&oprofile_stats.sample_lost_mmap_sem, 0);
+ atomic_set(&oprofile_stats.sample_lost_no_mm, 0);
atomic_set(&oprofile_stats.event_lost_overflow, 0);
}
@@ -68,8 +68,8 @@
&cpu_buf->sample_lost_task_exit);
}
- oprofilefs_create_ro_atomic(sb, dir, "sample_lost_mmap_sem",
- &oprofile_stats.sample_lost_mmap_sem);
+ oprofilefs_create_ro_atomic(sb, dir, "sample_lost_no_mm",
+ &oprofile_stats.sample_lost_no_mm);
oprofilefs_create_ro_atomic(sb, dir, "event_lost_overflow",
&oprofile_stats.event_lost_overflow);
}
diff -Naur -X dontdiff linux-cvs/drivers/oprofile/oprofile_stats.h linux-me/drivers/oprofile/oprofile_stats.h
--- linux-cvs/drivers/oprofile/oprofile_stats.h 2002-10-16 03:26:30.000000000 +0100
+++ linux-me/drivers/oprofile/oprofile_stats.h 2003-05-01 14:36:12.000000000 +0100
@@ -13,7 +13,7 @@
#include <asm/atomic.h>
struct oprofile_stat_struct {
- atomic_t sample_lost_mmap_sem;
+ atomic_t sample_lost_no_mm;
atomic_t event_lost_overflow;
};
We were doing del_timer_sync() on shutdown, but not ensuring that any queued work
was done as well.
diff -Naur -X dontdiff linux-cvs/drivers/oprofile/buffer_sync.c linux-me/drivers/oprofile/buffer_sync.c
--- linux-cvs/drivers/oprofile/buffer_sync.c 2003-04-05 18:44:49.000000000 +0100
+++ linux-me/drivers/oprofile/buffer_sync.c 2003-05-03 20:10:44.000000000 +0100
@@ -147,6 +170,8 @@
profile_event_unregister(EXIT_MMAP, &exit_mmap_nb);
profile_event_unregister(EXEC_UNMAP, &exec_unmap_nb);
del_timer_sync(&sync_timer);
+ /* timer might have queued work, make sure it's completed. */
+ flush_scheduled_work();
}