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Reimplement mutexs for Linux lock profiling/analysis

Browse Source 
For a generic explanation of why mutexs needed to be reimplemented
to work with the kernel lock profiling see commits:
  e811949a57 and
  d28db80fd0

The specific changes made to the mutex implemetation are as follows.
The Linux mutex structure is now directly embedded in the kmutex_t.
This allows a kmutex_t to be directly case to a mutex struct and
passed directly to the Linux primative.

Just like with the rwlocks it is critical that these functions be
implemented as '#defines to ensure the location information is
preserved.  The preprocessor can then do a direct replacement of
the Solaris primative with the linux primative.

Just as with the rwlocks we need to track the lock owner.  Here
things get a little more interesting because depending on your
kernel version, and how you've built your kernel Linux may already
do this for you.  If your running a 2.6.29 or newer kernel on a
SMP system the lock owner will be tracked.  This was added to Linux
to support adaptive mutexs, more on that shortly.  Alternately, your
kernel might track the lock owner if you've set CONFIG_DEBUG_MUTEXES
in the kernel build.  If neither of the above things is true for
your kernel the kmutex_t type will include and track the lock owner
to ensure correct behavior.  This is all handled by a new autoconf
check called SPL_AC_MUTEX_OWNER.

Concerning adaptive mutexs these are a very recent development and
they did not make it in to either the latest FC11 of SLES11 kernels.
Ideally, I'd love to see this kernel change appear in one of these
distros because it does help performance.  From Linux kernel commit:
  0d66bf6d3514b35eb6897629059443132992dbd7
  "Testing with Ingo's test-mutex application...
  gave a 345% boost for VFS scalability on my testbox"
However, if you don't want to backport this change yourself you
can still simply export the task_curr() symbol.  The kmutex_t
implementation will use this symbol when it's available to
provide it's own adaptive mutexs.

Finally, DEBUG_MUTEX support was removed including the proc handlers.
This was done because now that we are cleanly integrated with the
kernel profiling all this information and much much more is available
in debug kernel builds.  This code was now redundant.

Update mutexs validated on:
    - SLES10   (ppc64)
    - SLES11   (x86_64)
    - CHAOS4.2 (x86_64)
    - RHEL5.3  (x86_64)
    - RHEL6    (x86_64)
    - FC11     (x86_64)
This commit is contained in:
Brian Behlendorf 2009-09-25 14:47:01 -07:00
parent d28db80fd0
commit 4d54fdee1d
8 changed files with 596 additions and 835 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

43
config/spl-build.m4
View File

@ -23,7 +23,6 @@ AC_DEFUN([SPL_AC_CONFIG_KERNEL], [
SPL_AC_DEBUG
SPL_AC_DEBUG_KMEM
SPL_AC_DEBUG_MUTEX
SPL_AC_DEBUG_KSTAT
SPL_AC_DEBUG_CALLB
SPL_AC_TYPE_UINTPTR_T
@ -48,6 +47,7 @@ AC_DEFUN([SPL_AC_CONFIG_KERNEL], [
SPL_AC_KMALLOC_NODE
SPL_AC_MONOTONIC_CLOCK
SPL_AC_INODE_I_MUTEX
SPL_AC_MUTEX_OWNER
SPL_AC_MUTEX_LOCK_NESTED
SPL_AC_DIV64_64
SPL_AC_DIV64_U64
@ -256,28 +256,6 @@ AC_DEFUN([SPL_AC_DEBUG_KMEM], [
fi
])
AC_DEFUN([SPL_AC_DEBUG_MUTEX], [
AC_MSG_CHECKING([whether mutex debugging is enabled])
AC_ARG_ENABLE( [debug-mutex],
AS_HELP_STRING([--enable-debug-mutex],
[Enable mutex debug support (default off)]),
[ case "$enableval" in
yes) spl_ac_debug_mutex=yes ;;
no) spl_ac_debug_mutex=no ;;
*) AC_MSG_RESULT([Error!])
AC_MSG_ERROR([Bad value "$enableval" for --enable-debug-mutex]) ;;
esac ]
)
if test "$spl_ac_debug_mutex" = yes; then
AC_MSG_RESULT([yes])
AC_DEFINE([DEBUG_MUTEX], [1],
[Define to 1 to enable mutex debugging])
KERNELCPPFLAGS="${KERNELCPPFLAGS} -DDEBUG_MUTEX"
else
AC_MSG_RESULT([no])
fi
])
AC_DEFUN([SPL_AC_DEBUG_KSTAT], [
AC_MSG_CHECKING([whether kstat debugging is enabled])
AC_ARG_ENABLE( [debug-kstat],
@ -825,6 +803,25 @@ AC_DEFUN([SPL_AC_INODE_I_MUTEX], [
])
])
dnl #
dnl # 2.6.29 API change,
dnl # Adaptive mutexs introduced.
dnl #
AC_DEFUN([SPL_AC_MUTEX_OWNER], [
AC_MSG_CHECKING([whether struct mutex has owner])
SPL_LINUX_TRY_COMPILE([
#include <linux/mutex.h>
],[
struct mutex mtx;
mtx.owner = NULL;
],[
AC_MSG_RESULT(yes)
AC_DEFINE(HAVE_MUTEX_OWNER, 1, [struct mutex has owner])
],[
AC_MSG_RESULT(no)
])
])
dnl #
dnl # 2.6.18 API change,
dnl # First introduced 'mutex_lock_nested()' in include/linux/mutex.h,

251
configure vendored
View File

@ -1036,7 +1036,6 @@ Optional Features:
--disable-libtool-lock avoid locking (might break parallel builds)
--enable-debug Enable generic debug support (default off)
--enable-debug-kmem Enable kmem debug support (default off)
--enable-debug-mutex Enable mutex debug support (default off)
--enable-debug-kstat Enable kstat debug support (default off)
--enable-debug-callb Enable callb debug support (default off)
@ -3987,7 +3986,7 @@ ia64-*-hpux*)
;;
*-*-irix6*)
# Find out which ABI we are using.
echo '#line 3990 "configure"' > conftest.$ac_ext
echo '#line 3989 "configure"' > conftest.$ac_ext
if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
(eval $ac_compile) 2>&5
ac_status=$?
@ -5586,7 +5585,7 @@ fi
# Provide some information about the compiler.
echo "$as_me:5589:" \
echo "$as_me:5588:" \
"checking for Fortran 77 compiler version" >&5
ac_compiler=`set X $ac_compile; echo $2`
{ (eval echo "$as_me:$LINENO: \"$ac_compiler --version </dev/null >&5\"") >&5
@ -6649,11 +6648,11 @@ else
-e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
-e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
-e 's:$: $lt_compiler_flag:'`
(eval echo "\"\$as_me:6652: $lt_compile\"" >&5)
(eval echo "\"\$as_me:6651: $lt_compile\"" >&5)
(eval "$lt_compile" 2>conftest.err)
ac_status=$?
cat conftest.err >&5
echo "$as_me:6656: \$? = $ac_status" >&5
echo "$as_me:6655: \$? = $ac_status" >&5
if (exit $ac_status) && test -s "$ac_outfile"; then
# The compiler can only warn and ignore the option if not recognized
# So say no if there are warnings other than the usual output.
@ -6917,11 +6916,11 @@ else
-e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
-e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
-e 's:$: $lt_compiler_flag:'`
(eval echo "\"\$as_me:6920: $lt_compile\"" >&5)
(eval echo "\"\$as_me:6919: $lt_compile\"" >&5)
(eval "$lt_compile" 2>conftest.err)
ac_status=$?
cat conftest.err >&5
echo "$as_me:6924: \$? = $ac_status" >&5
echo "$as_me:6923: \$? = $ac_status" >&5
if (exit $ac_status) && test -s "$ac_outfile"; then
# The compiler can only warn and ignore the option if not recognized
# So say no if there are warnings other than the usual output.
@ -7021,11 +7020,11 @@ else
-e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
-e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
-e 's:$: $lt_compiler_flag:'`
(eval echo "\"\$as_me:7024: $lt_compile\"" >&5)
(eval echo "\"\$as_me:7023: $lt_compile\"" >&5)
(eval "$lt_compile" 2>out/conftest.err)
ac_status=$?
cat out/conftest.err >&5
echo "$as_me:7028: \$? = $ac_status" >&5
echo "$as_me:7027: \$? = $ac_status" >&5
if (exit $ac_status) && test -s out/conftest2.$ac_objext
then
# The compiler can only warn and ignore the option if not recognized
@ -8490,7 +8489,7 @@ linux*)
libsuff=
case "$host_cpu" in
x86_64*|s390x*|powerpc64*)
echo '#line 8493 "configure"' > conftest.$ac_ext
echo '#line 8492 "configure"' > conftest.$ac_ext
if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
(eval $ac_compile) 2>&5
ac_status=$?
@ -9387,7 +9386,7 @@ else
lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
lt_status=$lt_dlunknown
cat > conftest.$ac_ext <<EOF
#line 9390 "configure"
#line 9389 "configure"
#include "confdefs.h"
#if HAVE_DLFCN_H
@ -9487,7 +9486,7 @@ else
lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
lt_status=$lt_dlunknown
cat > conftest.$ac_ext <<EOF
#line 9490 "configure"
#line 9489 "configure"
#include "confdefs.h"
#if HAVE_DLFCN_H
@ -11830,11 +11829,11 @@ else
-e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
-e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
-e 's:$: $lt_compiler_flag:'`
(eval echo "\"\$as_me:11833: $lt_compile\"" >&5)
(eval echo "\"\$as_me:11832: $lt_compile\"" >&5)
(eval "$lt_compile" 2>conftest.err)
ac_status=$?
cat conftest.err >&5
echo "$as_me:11837: \$? = $ac_status" >&5
echo "$as_me:11836: \$? = $ac_status" >&5
if (exit $ac_status) && test -s "$ac_outfile"; then
# The compiler can only warn and ignore the option if not recognized
# So say no if there are warnings other than the usual output.
@ -11934,11 +11933,11 @@ else
-e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
-e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
-e 's:$: $lt_compiler_flag:'`
(eval echo "\"\$as_me:11937: $lt_compile\"" >&5)
(eval echo "\"\$as_me:11936: $lt_compile\"" >&5)
(eval "$lt_compile" 2>out/conftest.err)
ac_status=$?
cat out/conftest.err >&5
echo "$as_me:11941: \$? = $ac_status" >&5
echo "$as_me:11940: \$? = $ac_status" >&5
if (exit $ac_status) && test -s out/conftest2.$ac_objext
then
# The compiler can only warn and ignore the option if not recognized
@ -12470,7 +12469,7 @@ linux*)
libsuff=
case "$host_cpu" in
x86_64*|s390x*|powerpc64*)
echo '#line 12473 "configure"' > conftest.$ac_ext
echo '#line 12472 "configure"' > conftest.$ac_ext
if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
(eval $ac_compile) 2>&5
ac_status=$?
@ -13528,11 +13527,11 @@ else
-e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
-e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
-e 's:$: $lt_compiler_flag:'`
(eval echo "\"\$as_me:13531: $lt_compile\"" >&5)
(eval echo "\"\$as_me:13530: $lt_compile\"" >&5)
(eval "$lt_compile" 2>conftest.err)
ac_status=$?
cat conftest.err >&5
echo "$as_me:13535: \$? = $ac_status" >&5
echo "$as_me:13534: \$? = $ac_status" >&5
if (exit $ac_status) && test -s "$ac_outfile"; then
# The compiler can only warn and ignore the option if not recognized
# So say no if there are warnings other than the usual output.
@ -13632,11 +13631,11 @@ else
-e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
-e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
-e 's:$: $lt_compiler_flag:'`
(eval echo "\"\$as_me:13635: $lt_compile\"" >&5)
(eval echo "\"\$as_me:13634: $lt_compile\"" >&5)
(eval "$lt_compile" 2>out/conftest.err)
ac_status=$?
cat out/conftest.err >&5
echo "$as_me:13639: \$? = $ac_status" >&5
echo "$as_me:13638: \$? = $ac_status" >&5
if (exit $ac_status) && test -s out/conftest2.$ac_objext
then
# The compiler can only warn and ignore the option if not recognized
@ -15081,7 +15080,7 @@ linux*)
libsuff=
case "$host_cpu" in
x86_64*|s390x*|powerpc64*)
echo '#line 15084 "configure"' > conftest.$ac_ext
echo '#line 15083 "configure"' > conftest.$ac_ext
if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
(eval $ac_compile) 2>&5
ac_status=$?
@ -15859,11 +15858,11 @@ else
-e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
-e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
-e 's:$: $lt_compiler_flag:'`
(eval echo "\"\$as_me:15862: $lt_compile\"" >&5)
(eval echo "\"\$as_me:15861: $lt_compile\"" >&5)
(eval "$lt_compile" 2>conftest.err)
ac_status=$?
cat conftest.err >&5
echo "$as_me:15866: \$? = $ac_status" >&5
echo "$as_me:15865: \$? = $ac_status" >&5
if (exit $ac_status) && test -s "$ac_outfile"; then
# The compiler can only warn and ignore the option if not recognized
# So say no if there are warnings other than the usual output.
@ -16127,11 +16126,11 @@ else
-e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
-e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
-e 's:$: $lt_compiler_flag:'`
(eval echo "\"\$as_me:16130: $lt_compile\"" >&5)
(eval echo "\"\$as_me:16129: $lt_compile\"" >&5)
(eval "$lt_compile" 2>conftest.err)
ac_status=$?
cat conftest.err >&5
echo "$as_me:16134: \$? = $ac_status" >&5
echo "$as_me:16133: \$? = $ac_status" >&5
if (exit $ac_status) && test -s "$ac_outfile"; then
# The compiler can only warn and ignore the option if not recognized
# So say no if there are warnings other than the usual output.
@ -16231,11 +16230,11 @@ else
-e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
-e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
-e 's:$: $lt_compiler_flag:'`
(eval echo "\"\$as_me:16234: $lt_compile\"" >&5)
(eval echo "\"\$as_me:16233: $lt_compile\"" >&5)
(eval "$lt_compile" 2>out/conftest.err)
ac_status=$?
cat out/conftest.err >&5
echo "$as_me:16238: \$? = $ac_status" >&5
echo "$as_me:16237: \$? = $ac_status" >&5
if (exit $ac_status) && test -s out/conftest2.$ac_objext
then
# The compiler can only warn and ignore the option if not recognized
@ -17700,7 +17699,7 @@ linux*)
libsuff=
case "$host_cpu" in
x86_64*|s390x*|powerpc64*)
echo '#line 17703 "configure"' > conftest.$ac_ext
echo '#line 17702 "configure"' > conftest.$ac_ext
if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
(eval $ac_compile) 2>&5
ac_status=$?
@ -19143,37 +19142,6 @@ echo "${ECHO_T}no" >&6
fi
echo "$as_me:$LINENO: checking whether mutex debugging is enabled" >&5
echo $ECHO_N "checking whether mutex debugging is enabled... $ECHO_C" >&6
# Check whether --enable-debug-mutex or --disable-debug-mutex was given.
if test "${enable_debug_mutex+set}" = set; then
enableval="$enable_debug_mutex"
case "$enableval" in
yes) spl_ac_debug_mutex=yes ;;
no) spl_ac_debug_mutex=no ;;
*) echo "$as_me:$LINENO: result: Error!" >&5
echo "${ECHO_T}Error!" >&6
{ { echo "$as_me:$LINENO: error: Bad value \"$enableval\" for --enable-debug-mutex" >&5
echo "$as_me: error: Bad value \"$enableval\" for --enable-debug-mutex" >&2;}
{ (exit 1); exit 1; }; } ;;
esac
fi;
if test "$spl_ac_debug_mutex" = yes; then
echo "$as_me:$LINENO: result: yes" >&5
echo "${ECHO_T}yes" >&6
cat >>confdefs.h <<\_ACEOF
#define DEBUG_MUTEX 1
_ACEOF
KERNELCPPFLAGS="${KERNELCPPFLAGS} -DDEBUG_MUTEX"
else
echo "$as_me:$LINENO: result: no" >&5
echo "${ECHO_T}no" >&6
fi
echo "$as_me:$LINENO: checking whether kstat debugging is enabled" >&5
echo $ECHO_N "checking whether kstat debugging is enabled... $ECHO_C" >&6
# Check whether --enable-debug-kstat or --disable-debug-kstat was given.
@ -20562,6 +20530,72 @@ fi
echo "$as_me:$LINENO: checking whether struct mutex has owner" >&5
echo $ECHO_N "checking whether struct mutex has owner... $ECHO_C" >&6
cat >conftest.c <<_ACEOF
/* confdefs.h. */
_ACEOF
cat confdefs.h >>conftest.$ac_ext
cat >>conftest.$ac_ext <<_ACEOF
/* end confdefs.h. */
#include <linux/mutex.h>
int
main (void)
{
struct mutex mtx;
mtx.owner = NULL;
;
return 0;
}
_ACEOF
rm -Rf build && mkdir -p build
echo "obj-m := conftest.o" >build/Makefile
if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
{ (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
(eval $ac_try) 2>&5
ac_status=$?
echo "$as_me:$LINENO: \$? = $ac_status" >&5
(exit $ac_status); }; } >/dev/null && { ac_try='test -s build/conftest.o'
{ (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
(eval $ac_try) 2>&5
ac_status=$?
echo "$as_me:$LINENO: \$? = $ac_status" >&5
(exit $ac_status); }; }; then
echo "$as_me:$LINENO: result: yes" >&5
echo "${ECHO_T}yes" >&6
cat >>confdefs.h <<\_ACEOF
#define HAVE_MUTEX_OWNER 1
_ACEOF
else
echo "$as_me: failed program was:" >&5
sed 's/^/| /' conftest.$ac_ext >&5
echo "$as_me:$LINENO: result: no" >&5
echo "${ECHO_T}no" >&6
fi
rm -Rf build
echo "$as_me:$LINENO: checking whether mutex_lock_nested() is available" >&5
echo $ECHO_N "checking whether mutex_lock_nested() is available... $ECHO_C" >&6
@ -22151,37 +22185,6 @@ echo "${ECHO_T}no" >&6
fi
echo "$as_me:$LINENO: checking whether mutex debugging is enabled" >&5
echo $ECHO_N "checking whether mutex debugging is enabled... $ECHO_C" >&6
# Check whether --enable-debug-mutex or --disable-debug-mutex was given.
if test "${enable_debug_mutex+set}" = set; then
enableval="$enable_debug_mutex"
case "$enableval" in
yes) spl_ac_debug_mutex=yes ;;
no) spl_ac_debug_mutex=no ;;
*) echo "$as_me:$LINENO: result: Error!" >&5
echo "${ECHO_T}Error!" >&6
{ { echo "$as_me:$LINENO: error: Bad value \"$enableval\" for --enable-debug-mutex" >&5
echo "$as_me: error: Bad value \"$enableval\" for --enable-debug-mutex" >&2;}
{ (exit 1); exit 1; }; } ;;
esac
fi;
if test "$spl_ac_debug_mutex" = yes; then
echo "$as_me:$LINENO: result: yes" >&5
echo "${ECHO_T}yes" >&6
cat >>confdefs.h <<\_ACEOF
#define DEBUG_MUTEX 1
_ACEOF
KERNELCPPFLAGS="${KERNELCPPFLAGS} -DDEBUG_MUTEX"
else
echo "$as_me:$LINENO: result: no" >&5
echo "${ECHO_T}no" >&6
fi
echo "$as_me:$LINENO: checking whether kstat debugging is enabled" >&5
echo $ECHO_N "checking whether kstat debugging is enabled... $ECHO_C" >&6
# Check whether --enable-debug-kstat or --disable-debug-kstat was given.
@ -23570,6 +23573,72 @@ fi
echo "$as_me:$LINENO: checking whether struct mutex has owner" >&5
echo $ECHO_N "checking whether struct mutex has owner... $ECHO_C" >&6
cat >conftest.c <<_ACEOF
/* confdefs.h. */
_ACEOF
cat confdefs.h >>conftest.$ac_ext
cat >>conftest.$ac_ext <<_ACEOF
/* end confdefs.h. */
#include <linux/mutex.h>
int
main (void)
{
struct mutex mtx;
mtx.owner = NULL;
;
return 0;
}
_ACEOF
rm -Rf build && mkdir -p build
echo "obj-m := conftest.o" >build/Makefile
if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
{ (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
(eval $ac_try) 2>&5
ac_status=$?
echo "$as_me:$LINENO: \$? = $ac_status" >&5
(exit $ac_status); }; } >/dev/null && { ac_try='test -s build/conftest.o'
{ (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
(eval $ac_try) 2>&5
ac_status=$?
echo "$as_me:$LINENO: \$? = $ac_status" >&5
(exit $ac_status); }; }; then
echo "$as_me:$LINENO: result: yes" >&5
echo "${ECHO_T}yes" >&6
cat >>confdefs.h <<\_ACEOF
#define HAVE_MUTEX_OWNER 1
_ACEOF
else
echo "$as_me: failed program was:" >&5
sed 's/^/| /' conftest.$ac_ext >&5
echo "$as_me:$LINENO: result: no" >&5
echo "${ECHO_T}no" >&6
fi
rm -Rf build
echo "$as_me:$LINENO: checking whether mutex_lock_nested() is available" >&5
echo $ECHO_N "checking whether mutex_lock_nested() is available... $ECHO_C" >&6

1
include/sys/condvar.h
View File

@ -33,6 +33,7 @@ extern "C" {
#include <linux/module.h>
#include <linux/wait.h>
#include <sys/kmem.h>
#include <sys/mutex.h>
/* The kcondvar_t struct is protected by mutex taken externally before

233
include/sys/mutex.h
View File

@ -1,7 +1,7 @@
/*
* This file is part of the SPL: Solaris Porting Layer.
*
* Copyright (c) 2008 Lawrence Livermore National Security, LLC.
* Copyright (c) 2009 Lawrence Livermore National Security, LLC.
* Produced at Lawrence Livermore National Laboratory
* Written by:
* Brian Behlendorf <behlendorf1@llnl.gov>,
@ -25,88 +25,177 @@
*/
#ifndef _SPL_MUTEX_H
#define _SPL_MUTEX_H
#define _SPL_MUTEX_H
#ifdef __cplusplus
extern "C" {
#endif
#include <linux/module.h>
#include <linux/hardirq.h>
#include <sys/types.h>
#include <sys/kmem.h>
#include <linux/mutex.h>
#define MUTEX_DEFAULT 0
#define MUTEX_SPIN 1
#define MUTEX_ADAPTIVE 2
typedef enum {
MUTEX_DEFAULT = 0,
MUTEX_SPIN = 1,
MUTEX_ADAPTIVE = 2
} kmutex_type_t;
#define MUTEX_ENTER_TOTAL 0
#define MUTEX_ENTER_NOT_HELD 1
#define MUTEX_ENTER_SPIN 2
#define MUTEX_ENTER_SLEEP 3
#define MUTEX_TRYENTER_TOTAL 4
#define MUTEX_TRYENTER_NOT_HELD 5
#define MUTEX_STATS_SIZE 6
#ifdef HAVE_MUTEX_OWNER
#define KM_MAGIC 0x42424242
#define KM_POISON 0x84
typedef struct mutex kmutex_t;
static inline kthread_t *
mutex_owner(kmutex_t *mp)
{
if (mp->owner)
return (mp->owner)->task;
return NULL;
}
#define mutex_owned(mp) (mutex_owner(mp) == current)
#define MUTEX_HELD(mp) mutex_owned(mp)
#undef mutex_init
#define mutex_init(mp, name, type, ibc) \
({ \
static struct lock_class_key __key; \
ASSERT(type == MUTEX_DEFAULT); \
\
__mutex_init((mp), #mp, &__key); \
})
/* #define mutex_destroy(mp) ((void)0) */
#define mutex_tryenter(mp) mutex_trylock(mp)
#define mutex_enter(mp) mutex_lock(mp)
#define mutex_exit(mp) mutex_unlock(mp)
#else /* HAVE_MUTEX_OWNER */
typedef struct {
int32_t km_magic;
int16_t km_type;
int16_t km_name_size;
char *km_name;
struct task_struct *km_owner;
struct semaphore *km_sem;
#ifdef DEBUG_MUTEX
int *km_stats;
struct list_head km_list;
#endif
struct mutex m_mutex;
kthread_t *m_owner;
} kmutex_t;
extern int mutex_spin_max;
#ifdef HAVE_TASK_CURR
extern int spl_mutex_spin_max(void);
#else /* HAVE_TASK_CURR */
# define task_curr(owner) 0
# define spl_mutex_spin_max() 0
#endif /* HAVE_TASK_CURR */
#ifdef DEBUG_MUTEX
extern int mutex_stats[MUTEX_STATS_SIZE];
extern spinlock_t mutex_stats_lock;
extern struct list_head mutex_stats_list;
#define MUTEX_STAT_INC(stats, stat) ((stats)[stat]++)
#else
#define MUTEX_STAT_INC(stats, stat)
#endif
#define MUTEX(mp) ((struct mutex *)(mp))
static inline kthread_t *
spl_mutex_get_owner(kmutex_t *mp)
{
return mp->m_owner;
}
static inline void
spl_mutex_set_owner(kmutex_t *mp)
{
unsigned long flags;
spin_lock_irqsave(&MUTEX(mp)->wait_lock, flags);
mp->m_owner = current;
spin_unlock_irqrestore(&MUTEX(mp)->wait_lock, flags);
}
static inline void
spl_mutex_clear_owner(kmutex_t *mp)
{
unsigned long flags;
spin_lock_irqsave(&MUTEX(mp)->wait_lock, flags);
mp->m_owner = NULL;
spin_unlock_irqrestore(&MUTEX(mp)->wait_lock, flags);
}
static inline kthread_t *
mutex_owner(kmutex_t *mp)
{
unsigned long flags;
kthread_t *owner;
spin_lock_irqsave(&MUTEX(mp)->wait_lock, flags);
owner = spl_mutex_get_owner(mp);
spin_unlock_irqrestore(&MUTEX(mp)->wait_lock, flags);
return owner;
}
#define mutex_owned(mp) (mutex_owner(mp) == current)
#define MUTEX_HELD(mp) mutex_owned(mp)
/*
* The following functions must be a #define and not static inline.
* This ensures that the native linux mutex functions (lock/unlock)
* will be correctly located in the users code which is important
* for the built in kernel lock analysis tools
*/
#undef mutex_init
#define mutex_init(mp, name, type, ibc) \
({ \
static struct lock_class_key __key; \
ASSERT(type == MUTEX_DEFAULT); \
\
__mutex_init(MUTEX(mp), #mp, &__key); \
spl_mutex_clear_owner(mp); \
})
#undef mutex_destroy
#define mutex_destroy(mp) \
({ \
VERIFY(!MUTEX_HELD(mp)); \
})
#define mutex_tryenter(mp) \
({ \
int _rc_; \
\
if ((_rc_ = mutex_trylock(MUTEX(mp))) == 1) \
spl_mutex_set_owner(mp); \
\
_rc_; \
})
/*
* Adaptive mutexs assume that the lock may be held by a task running
* on a different cpu. The expectation is that the task will drop the
* lock before leaving the head of the run queue. So the ideal thing
* to do is spin until we acquire the lock and avoid a context switch.
* However it is also possible the task holding the lock yields the
* processor with out dropping lock. In this case, we know it's going
* to be a while so we stop spinning and go to sleep waiting for the
* lock to be available. This should strike the optimum balance
* between spinning and sleeping waiting for a lock.
*/
#define mutex_enter(mp) \
({ \
kthread_t *_owner_; \
int _rc_, _count_; \
\
_rc_ = 0; \
_count_ = 0; \
_owner_ = mutex_owner(mp); \
\
while (_owner_ && task_curr(_owner_) && \
_count_ <= spl_mutex_spin_max()) { \
if ((_rc_ = mutex_trylock(MUTEX(mp)))) \
break; \
\
_count_++; \
} \
\
if (!_rc_) \
mutex_lock(MUTEX(mp)); \
\
spl_mutex_set_owner(mp); \
})
#define mutex_exit(mp) \
({ \
spl_mutex_clear_owner(mp); \
mutex_unlock(MUTEX(mp)); \
})
#endif /* HAVE_MUTEX_OWNER */
int spl_mutex_init(void);
void spl_mutex_fini(void);
extern int __spl_mutex_init(kmutex_t *mp, char *name, int type, void *ibc);
extern void __spl_mutex_destroy(kmutex_t *mp);
extern int __mutex_tryenter(kmutex_t *mp);
extern void __mutex_enter(kmutex_t *mp);
extern void __mutex_exit(kmutex_t *mp);
extern int __mutex_owned(kmutex_t *mp);
extern kthread_t *__spl_mutex_owner(kmutex_t *mp);
#undef mutex_init
#undef mutex_destroy
#define mutex_init(mp, name, type, ibc) \
({ \
/* May never fail or all subsequent mutex_* calls will ASSERT */\
if ((name) == NULL) \
while(__spl_mutex_init(mp, #mp, type, ibc)); \
else \
while(__spl_mutex_init(mp, name, type, ibc)); \
})
#define mutex_destroy(mp) __spl_mutex_destroy(mp)
#define mutex_tryenter(mp) __mutex_tryenter(mp)
#define mutex_enter(mp) __mutex_enter(mp)
#define mutex_exit(mp) __mutex_exit(mp)
#define mutex_owned(mp) __mutex_owned(mp)
#define mutex_owner(mp) __spl_mutex_owner(mp)
#define MUTEX_HELD(mp) mutex_owned(mp)
#ifdef __cplusplus
}
#endif
#endif /* _SPL_MUTEX_H */
#endif /* _SPL_MUTEX_H */

305
module/spl/spl-mutex.c
View File

@ -1,7 +1,7 @@
/*
* This file is part of the SPL: Solaris Porting Layer.
*
* Copyright (c) 2008 Lawrence Livermore National Security, LLC.
* Copyright (c) 2009 Lawrence Livermore National Security, LLC.
* Produced at Lawrence Livermore National Laboratory
* Written by:
* Brian Behlendorf <behlendorf1@llnl.gov>,
@ -32,277 +32,46 @@
#define DEBUG_SUBSYSTEM S_MUTEX
/* Mutex implementation based on those found in Solaris. This means
* they the MUTEX_DEFAULT type is an adaptive mutex. When calling
* mutex_enter() your process will spin waiting for the lock if it's
* likely the lock will be free'd shortly. If it looks like the
* lock will be held for a longer time we schedule and sleep waiting
* for it. This determination is made by checking if the holder of
* the lock is currently running on cpu or sleeping waiting to be
* scheduled. If the holder is currently running it's likely the
* lock will be shortly dropped.
/*
* While a standard mutex implementation has been available in the kernel
* for quite some time. It was not until 2.6.29 and latter kernels that
* adaptive mutexs were embraced and integrated with the scheduler. This
* brought a significant performance improvement, but just as importantly
* it added a lock owner to the generic mutex outside CONFIG_DEBUG_MUTEXES
* builds. This is critical for correctly supporting the mutex_owner()
* Solaris primitive. When the owner is available we use a pure Linux
* mutex implementation. When the owner is not available we still use
* Linux mutexs as a base but also reserve space for an owner field right
* after the mutex structure.
*
* XXX: This is basically a rough implementation to see if this
* helps our performance. If it does a more careful implementation
* should be done, perhaps in assembly.
* In the case when HAVE_MUTEX_OWNER is not defined your code may
* still me able to leverage adaptive mutexs. As long as the task_curr()
* symbol is exported this code will provide a poor mans adaptive mutex
* implementation. However, this is not required and if the symbol is
* unavailable we provide a standard mutex.
*/
/* 0: Never spin when trying to aquire lock
* -1: Spin until aquired or holder yeilds without dropping lock
#ifndef HAVE_MUTEX_OWNER
#ifdef HAVE_TASK_CURR
/*
* mutex_spin_max = { 0, -1, 1-MAX_INT }
* 0: Never spin when trying to acquire lock
* -1: Spin until acquired or holder yields without dropping lock
* 1-MAX_INT: Spin for N attempts before sleeping for lock
*/
int mutex_spin_max = 0;
#ifdef DEBUG_MUTEX
int mutex_stats[MUTEX_STATS_SIZE] = { 0 };
spinlock_t mutex_stats_lock;
struct list_head mutex_stats_list;
#endif
int
__spl_mutex_init(kmutex_t *mp, char *name, int type, void *ibc)
{
int flags = KM_SLEEP;
ASSERT(mp);
ASSERT(name);
ASSERT(ibc == NULL);
mp->km_name = NULL;
mp->km_name_size = strlen(name) + 1;
switch (type) {
case MUTEX_DEFAULT:
mp->km_type = MUTEX_ADAPTIVE;
break;
case MUTEX_SPIN:
case MUTEX_ADAPTIVE:
mp->km_type = type;
break;
default:
SBUG();
}
/* We may be called when there is a non-zero preempt_count or
* interrupts are disabled is which case we must not sleep.
*/
if (current_thread_info()->preempt_count || irqs_disabled())
flags = KM_NOSLEEP;
/* Semaphore kmem_alloc'ed to keep struct size down (<64b) */
mp->km_sem = kmem_alloc(sizeof(struct semaphore), flags);
if (mp->km_sem == NULL)
return -ENOMEM;
mp->km_name = kmem_alloc(mp->km_name_size, flags);
if (mp->km_name == NULL) {
kmem_free(mp->km_sem, sizeof(struct semaphore));
return -ENOMEM;
}
sema_init(mp->km_sem, 1);
strncpy(mp->km_name, name, mp->km_name_size);
#ifdef DEBUG_MUTEX
mp->km_stats = kmem_zalloc(sizeof(int) * MUTEX_STATS_SIZE, flags);
if (mp->km_stats == NULL) {
kmem_free(mp->km_name, mp->km_name_size);
kmem_free(mp->km_sem, sizeof(struct semaphore));
return -ENOMEM;
}
/* XXX - This appears to be a much more contended lock than I
* would have expected. To run with this debugging enabled and
* get reasonable performance we may need to be more clever and
* do something like hash the mutex ptr on to one of several
* lists to ease this single point of contention.
*/
spin_lock(&mutex_stats_lock);
list_add_tail(&mp->km_list, &mutex_stats_list);
spin_unlock(&mutex_stats_lock);
#endif
mp->km_magic = KM_MAGIC;
mp->km_owner = NULL;
return 0;
}
EXPORT_SYMBOL(__spl_mutex_init);
void
__spl_mutex_destroy(kmutex_t *mp)
{
ASSERT(mp);
ASSERT(mp->km_magic == KM_MAGIC);
#ifdef DEBUG_MUTEX
spin_lock(&mutex_stats_lock);
list_del_init(&mp->km_list);
spin_unlock(&mutex_stats_lock);
kmem_free(mp->km_stats, sizeof(int) * MUTEX_STATS_SIZE);
#endif
kmem_free(mp->km_name, mp->km_name_size);
kmem_free(mp->km_sem, sizeof(struct semaphore));
memset(mp, KM_POISON, sizeof(*mp));
}
EXPORT_SYMBOL(__spl_mutex_destroy);
/* Return 1 if we acquired the mutex, else zero. */
int
__mutex_tryenter(kmutex_t *mp)
{
int rc;
ENTRY;
ASSERT(mp);
ASSERT(mp->km_magic == KM_MAGIC);
MUTEX_STAT_INC(mutex_stats, MUTEX_TRYENTER_TOTAL);
MUTEX_STAT_INC(mp->km_stats, MUTEX_TRYENTER_TOTAL);
rc = down_trylock(mp->km_sem);
if (rc == 0) {
ASSERT(mp->km_owner == NULL);
mp->km_owner = current;
MUTEX_STAT_INC(mutex_stats, MUTEX_TRYENTER_NOT_HELD);
MUTEX_STAT_INC(mp->km_stats, MUTEX_TRYENTER_NOT_HELD);
}
RETURN(!rc);
}
EXPORT_SYMBOL(__mutex_tryenter);
#ifndef HAVE_TASK_CURR
#define task_curr(owner) 0
#endif
static void
mutex_enter_adaptive(kmutex_t *mp)
{
struct task_struct *owner;
int count = 0;
/* Lock is not held so we expect to aquire the lock */
if ((owner = mp->km_owner) == NULL) {
down(mp->km_sem);
MUTEX_STAT_INC(mutex_stats, MUTEX_ENTER_NOT_HELD);
MUTEX_STAT_INC(mp->km_stats, MUTEX_ENTER_NOT_HELD);
} else {
/* The lock is held by a currently running task which
* we expect will drop the lock before leaving the
* head of the runqueue. So the ideal thing to do
* is spin until we aquire the lock and avoid a
* context switch. However it is also possible the
* task holding the lock yields the processor with
* out dropping lock. In which case, we know it's
* going to be a while so we stop spinning and go
* to sleep waiting for the lock to be available.
* This should strike the optimum balance between
* spinning and sleeping waiting for a lock.
*/
while (task_curr(owner) && (count <= mutex_spin_max)) {
if (down_trylock(mp->km_sem) == 0) {
MUTEX_STAT_INC(mutex_stats, MUTEX_ENTER_SPIN);
MUTEX_STAT_INC(mp->km_stats, MUTEX_ENTER_SPIN);
GOTO(out, count);
}
count++;
}
/* The lock is held by a sleeping task so it's going to
* cost us minimally one context switch. We might as
* well sleep and yield the processor to other tasks.
*/
down(mp->km_sem);
MUTEX_STAT_INC(mutex_stats, MUTEX_ENTER_SLEEP);
MUTEX_STAT_INC(mp->km_stats, MUTEX_ENTER_SLEEP);
}
out:
MUTEX_STAT_INC(mutex_stats, MUTEX_ENTER_TOTAL);
MUTEX_STAT_INC(mp->km_stats, MUTEX_ENTER_TOTAL);
}
void
__mutex_enter(kmutex_t *mp)
{
ENTRY;
ASSERT(mp);
ASSERT(mp->km_magic == KM_MAGIC);
switch (mp->km_type) {
case MUTEX_SPIN:
while (down_trylock(mp->km_sem));
MUTEX_STAT_INC(mutex_stats, MUTEX_ENTER_SPIN);
MUTEX_STAT_INC(mp->km_stats, MUTEX_ENTER_SPIN);
break;
case MUTEX_ADAPTIVE:
mutex_enter_adaptive(mp);
break;
}
ASSERT(mp->km_owner == NULL);
mp->km_owner = current;
EXIT;
}
EXPORT_SYMBOL(__mutex_enter);
void
__mutex_exit(kmutex_t *mp)
{
ENTRY;
ASSERT(mp);
ASSERT(mp->km_magic == KM_MAGIC);
ASSERT(mp->km_owner == current);
mp->km_owner = NULL;
up(mp->km_sem);
EXIT;
}
EXPORT_SYMBOL(__mutex_exit);
/* Return 1 if mutex is held by current process, else zero. */
int
__mutex_owned(kmutex_t *mp)
{
ENTRY;
ASSERT(mp);
ASSERT(mp->km_magic == KM_MAGIC);
RETURN(mp->km_owner == current);
}
EXPORT_SYMBOL(__mutex_owned);
/* Return owner if mutex is owned, else NULL. */
kthread_t *
__spl_mutex_owner(kmutex_t *mp)
{
ENTRY;
ASSERT(mp);
ASSERT(mp->km_magic == KM_MAGIC);
RETURN(mp->km_owner);
}
EXPORT_SYMBOL(__spl_mutex_owner);
int
spl_mutex_init(void)
{
ENTRY;
#ifdef DEBUG_MUTEX
spin_lock_init(&mutex_stats_lock);
INIT_LIST_HEAD(&mutex_stats_list);
#endif
RETURN(0);
}
void
spl_mutex_fini(void)
{
ENTRY;
#ifdef DEBUG_MUTEX
ASSERT(list_empty(&mutex_stats_list));
#endif
EXIT;
}
module_param(mutex_spin_max, int, 0644);
MODULE_PARM_DESC(mutex_spin_max, "Spin a maximum of N times to aquire lock");
MODULE_PARM_DESC(mutex_spin_max, "Spin a maximum of N times to acquire lock");
int
spl_mutex_spin_max(void)
{
return mutex_spin_max;
}
EXPORT_SYMBOL(spl_mutex_spin_max);
#endif /* HAVE_TASK_CURR */
#endif /* !HAVE_MUTEX_OWNER */
int spl_mutex_init(void) { return 0; }
void spl_mutex_fini(void) { }

172
module/spl/spl-proc.c
View File

@ -41,12 +41,8 @@ static unsigned long table_max = ~0;
static struct ctl_table_header *spl_header = NULL;
#endif /* CONFIG_SYSCTL */
#if defined(DEBUG_MUTEX) || defined(DEBUG_KMEM) || defined(DEBUG_KSTAT)
#if defined(DEBUG_KMEM) || defined(DEBUG_KSTAT)
static struct proc_dir_entry *proc_spl = NULL;
#ifdef DEBUG_MUTEX
static struct proc_dir_entry *proc_spl_mutex = NULL;
static struct proc_dir_entry *proc_spl_mutex_stats = NULL;
#endif /* DEBUG_MUTEX */
#ifdef DEBUG_KMEM
static struct proc_dir_entry *proc_spl_kmem = NULL;
static struct proc_dir_entry *proc_spl_kmem_slab = NULL;
@ -54,7 +50,7 @@ static struct proc_dir_entry *proc_spl_kmem_slab = NULL;
#ifdef DEBUG_KSTAT
struct proc_dir_entry *proc_spl_kstat = NULL;
#endif /* DEBUG_KSTAT */
#endif /* DEBUG_MUTEX || DEBUG_KMEM || DEBUG_KSTAT */
#endif /* DEBUG_KMEM || DEBUG_KSTAT */
#ifdef HAVE_CTL_UNNUMBERED
@ -105,10 +101,6 @@ struct proc_dir_entry *proc_spl_kstat = NULL;
#define CTL_KMEM_ALLOC_FAILED CTL_UNNUMBERED /* Cache allocations failed */
#endif
#define CTL_MUTEX_STATS CTL_UNNUMBERED /* Global mutex statistics */
#define CTL_MUTEX_STATS_PER CTL_UNNUMBERED /* Per mutex statistics */
#define CTL_MUTEX_SPIN_MAX CTL_UNNUMBERED /* Max mutex spin iterations */
#else /* HAVE_CTL_UNNUMBERED */
enum {
@ -159,10 +151,6 @@ enum {
CTL_KMEM_VMEMUSED, /* Alloc'd vmem bytes */
CTL_KMEM_VMEMMAX, /* Max alloc'd by vmem bytes */
#endif
CTL_MUTEX_STATS, /* Global mutex statistics */
CTL_MUTEX_STATS_PER, /* Per mutex statistics */
CTL_MUTEX_SPIN_MAX, /* Maximum mutex spin iterations */
};
#endif /* HAVE_CTL_UNNUMBERED */
@ -589,103 +577,6 @@ proc_dofreemem(struct ctl_table *table, int write, struct file *filp,
RETURN(rc);
}
#ifdef DEBUG_MUTEX
static void
mutex_seq_show_headers(struct seq_file *f)
{
seq_printf(f, "%-36s %-4s %-16s\t"
"e_tot\te_nh\te_sp\te_sl\tte_tot\tte_nh\n",
"name", "type", "owner");
}
static int
mutex_seq_show(struct seq_file *f, void *p)
{
kmutex_t *mp = p;
char t = 'X';
int i;
ASSERT(mp->km_magic == KM_MAGIC);
switch (mp->km_type) {
case MUTEX_DEFAULT: t = 'D'; break;
case MUTEX_SPIN: t = 'S'; break;
case MUTEX_ADAPTIVE: t = 'A'; break;
default:
SBUG();
}
seq_printf(f, "%-36s %c ", mp->km_name, t);
if (mp->km_owner)
seq_printf(f, "%p\t", mp->km_owner);
else
seq_printf(f, "%-16s\t", "<not held>");
for (i = 0; i < MUTEX_STATS_SIZE; i++)
seq_printf(f, "%d%c", mp->km_stats[i],
(i + 1 == MUTEX_STATS_SIZE) ? '\n' : '\t');
return 0;
}
static void *
mutex_seq_start(struct seq_file *f, loff_t *pos)
{
struct list_head *p;
loff_t n = *pos;
ENTRY;
spin_lock(&mutex_stats_lock);
if (!n)
mutex_seq_show_headers(f);
p = mutex_stats_list.next;
while (n--) {
p = p->next;
if (p == &mutex_stats_list)
RETURN(NULL);
}
RETURN(list_entry(p, kmutex_t, km_list));
}
static void *
mutex_seq_next(struct seq_file *f, void *p, loff_t *pos)
{
kmutex_t *mp = p;
ENTRY;
++*pos;
RETURN((mp->km_list.next == &mutex_stats_list) ?
NULL : list_entry(mp->km_list.next, kmutex_t, km_list));
}
static void
mutex_seq_stop(struct seq_file *f, void *v)
{
spin_unlock(&mutex_stats_lock);
}
static struct seq_operations mutex_seq_ops = {
.show = mutex_seq_show,
.start = mutex_seq_start,
.next = mutex_seq_next,
.stop = mutex_seq_stop,
};
static int
proc_mutex_open(struct inode *inode, struct file *filp)
{
return seq_open(filp, &mutex_seq_ops);
}
static struct file_operations proc_mutex_operations = {
.open = proc_mutex_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
#endif /* DEBUG_MUTEX */
#ifdef DEBUG_KMEM
static void
slab_seq_show_headers(struct seq_file *f)
@ -968,28 +859,6 @@ static struct ctl_table spl_vm_table[] = {
{0},
};
#ifdef DEBUG_MUTEX
static struct ctl_table spl_mutex_table[] = {
{
.ctl_name = CTL_MUTEX_STATS,
.procname = "stats",
.data = &mutex_stats,
.maxlen = sizeof(int) * MUTEX_STATS_SIZE,
.mode = 0444,
.proc_handler = &proc_dointvec,
},
{
.ctl_name = CTL_MUTEX_SPIN_MAX,
.procname = "spin_max",
.data = &mutex_spin_max,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{0},
};
#endif /* DEBUG_MUTEX */
#ifdef DEBUG_KMEM
static struct ctl_table spl_kmem_table[] = {
{
@ -1088,14 +957,6 @@ static struct ctl_table spl_table[] = {
.mode = 0555,
.child = spl_vm_table,
},
#ifdef DEBUG_MUTEX
{
.ctl_name = CTL_SPL_MUTEX,
.procname = "mutex",
.mode = 0555,
.child = spl_mutex_table,
},
#endif
#ifdef DEBUG_KMEM
{
.ctl_name = CTL_SPL_KMEM,
@ -1180,24 +1041,11 @@ proc_init(void)
RETURN(-EUNATCH);
#endif /* CONFIG_SYSCTL */
#if defined(DEBUG_MUTEX) || defined(DEBUG_KMEM) || defined(DEBUG_KSTAT)
#if defined(DEBUG_KMEM) || defined(DEBUG_KSTAT)
proc_spl = proc_mkdir("spl", NULL);
if (proc_spl == NULL)
GOTO(out, rc = -EUNATCH);
#ifdef DEBUG_MUTEX
proc_spl_mutex = proc_mkdir("mutex", proc_spl);
if (proc_spl_mutex == NULL)
GOTO(out, rc = -EUNATCH);
proc_spl_mutex_stats = create_proc_entry("stats_per", 0444,
proc_spl_mutex);
if (proc_spl_mutex_stats == NULL)
GOTO(out, rc = -EUNATCH);
proc_spl_mutex_stats->proc_fops = &proc_mutex_operations;
#endif /* DEBUG_MUTEX */
#ifdef DEBUG_KMEM
proc_spl_kmem = proc_mkdir("kmem", proc_spl);
if (proc_spl_kmem == NULL)
@ -1223,16 +1071,12 @@ out:
remove_proc_entry("slab", proc_spl_kmem);
#endif
remove_proc_entry("kmem", proc_spl);
#ifdef DEBUG_MUTEX
remove_proc_entry("stats_per", proc_spl_mutex);
#endif
remove_proc_entry("mutex", proc_spl);
remove_proc_entry("spl", NULL);
#ifdef CONFIG_SYSCTL
spl_unregister_sysctl_table(spl_header);
#endif /* CONFIG_SYSCTL */
}
#endif /* DEBUG_MUTEX || DEBUG_KMEM || DEBUG_KSTAT */
#endif /* DEBUG_KMEM || DEBUG_KSTAT */
RETURN(rc);
}
@ -1242,18 +1086,14 @@ proc_fini(void)
{
ENTRY;
#if defined(DEBUG_MUTEX) || defined(DEBUG_KMEM) || defined(DEBUG_KSTAT)
#if defined(DEBUG_KMEM) || defined(DEBUG_KSTAT)
remove_proc_entry("kstat", proc_spl);
#ifdef DEBUG_KMEM
remove_proc_entry("slab", proc_spl_kmem);
#endif
remove_proc_entry("kmem", proc_spl);
#ifdef DEBUG_MUTEX
remove_proc_entry("stats_per", proc_spl_mutex);
#endif
remove_proc_entry("mutex", proc_spl);
remove_proc_entry("spl", NULL);
#endif /* DEBUG_MUTEX || DEBUG_KMEM || DEBUG_KSTAT */
#endif /* DEBUG_KMEM || DEBUG_KSTAT */
#ifdef CONFIG_SYSCTL
ASSERT(spl_header != NULL);

420
module/splat/splat-mutex.c
View File

@ -26,296 +26,292 @@
#include "splat-internal.h"
#define SPLAT_MUTEX_NAME "mutex"
#define SPLAT_MUTEX_DESC "Kernel Mutex Tests"
#define SPLAT_MUTEX_NAME "mutex"
#define SPLAT_MUTEX_DESC "Kernel Mutex Tests"
#define SPLAT_MUTEX_TEST1_ID 0x0401
#define SPLAT_MUTEX_TEST1_NAME "tryenter"
#define SPLAT_MUTEX_TEST1_DESC "Validate mutex_tryenter() correctness"
#define SPLAT_MUTEX_TEST1_ID 0x0401
#define SPLAT_MUTEX_TEST1_NAME "tryenter"
#define SPLAT_MUTEX_TEST1_DESC "Validate mutex_tryenter() correctness"
#define SPLAT_MUTEX_TEST2_ID 0x0402
#define SPLAT_MUTEX_TEST2_NAME "race"
#define SPLAT_MUTEX_TEST2_DESC "Many threads entering/exiting the mutex"
#define SPLAT_MUTEX_TEST2_ID 0x0402
#define SPLAT_MUTEX_TEST2_NAME "race"
#define SPLAT_MUTEX_TEST2_DESC "Many threads entering/exiting the mutex"
#define SPLAT_MUTEX_TEST3_ID 0x0403
#define SPLAT_MUTEX_TEST3_NAME "owned"
#define SPLAT_MUTEX_TEST3_DESC "Validate mutex_owned() correctness"
#define SPLAT_MUTEX_TEST3_ID 0x0403
#define SPLAT_MUTEX_TEST3_NAME "owned"
#define SPLAT_MUTEX_TEST3_DESC "Validate mutex_owned() correctness"
#define SPLAT_MUTEX_TEST4_ID 0x0404
#define SPLAT_MUTEX_TEST4_NAME "owner"
#define SPLAT_MUTEX_TEST4_DESC "Validate mutex_owner() correctness"
#define SPLAT_MUTEX_TEST4_ID 0x0404
#define SPLAT_MUTEX_TEST4_NAME "owner"
#define SPLAT_MUTEX_TEST4_DESC "Validate mutex_owner() correctness"
#define SPLAT_MUTEX_TEST_MAGIC 0x115599DDUL
#define SPLAT_MUTEX_TEST_NAME "mutex_test"
#define SPLAT_MUTEX_TEST_TASKQ "mutex_taskq"
#define SPLAT_MUTEX_TEST_COUNT 128
#define SPLAT_MUTEX_TEST_MAGIC 0x115599DDUL
#define SPLAT_MUTEX_TEST_NAME "mutex_test"
#define SPLAT_MUTEX_TEST_TASKQ "mutex_taskq"
#define SPLAT_MUTEX_TEST_COUNT 128
typedef struct mutex_priv {
unsigned long mp_magic;
struct file *mp_file;
kmutex_t mp_mtx;
int mp_rc;
kmutex_t mp_mtx;
int mp_rc;
} mutex_priv_t;
static void
splat_mutex_test1_func(void *arg)
{
mutex_priv_t *mp = (mutex_priv_t *)arg;
ASSERT(mp->mp_magic == SPLAT_MUTEX_TEST_MAGIC);
mutex_priv_t *mp = (mutex_priv_t *)arg;
ASSERT(mp->mp_magic == SPLAT_MUTEX_TEST_MAGIC);
if (mutex_tryenter(&mp->mp_mtx)) {
mp->mp_rc = 0;
mutex_exit(&mp->mp_mtx);
} else {
mp->mp_rc = -EBUSY;
}
if (mutex_tryenter(&mp->mp_mtx)) {
mp->mp_rc = 0;
mutex_exit(&mp->mp_mtx);
} else {
mp->mp_rc = -EBUSY;
}
}
static int
splat_mutex_test1(struct file *file, void *arg)
{
mutex_priv_t *mp;
taskq_t *tq;
int id, rc = 0;
mutex_priv_t *mp;
taskq_t *tq;
int id, rc = 0;
mp = (mutex_priv_t *)kmalloc(sizeof(*mp), GFP_KERNEL);
if (mp == NULL)
return -ENOMEM;
mp = (mutex_priv_t *)kmalloc(sizeof(*mp), GFP_KERNEL);
if (mp == NULL)
return -ENOMEM;
tq = taskq_create(SPLAT_MUTEX_TEST_TASKQ, 1, maxclsyspri,
50, INT_MAX, TASKQ_PREPOPULATE);
if (tq == NULL) {
rc = -ENOMEM;
goto out2;
}
tq = taskq_create(SPLAT_MUTEX_TEST_TASKQ, 1, maxclsyspri,
50, INT_MAX, TASKQ_PREPOPULATE);
if (tq == NULL) {
rc = -ENOMEM;
goto out2;
}
mp->mp_magic = SPLAT_MUTEX_TEST_MAGIC;
mp->mp_file = file;
mutex_init(&mp->mp_mtx, SPLAT_MUTEX_TEST_NAME, MUTEX_DEFAULT, NULL);
mutex_enter(&mp->mp_mtx);
mp->mp_magic = SPLAT_MUTEX_TEST_MAGIC;
mp->mp_file = file;
mutex_init(&mp->mp_mtx, SPLAT_MUTEX_TEST_NAME, MUTEX_DEFAULT, NULL);
mutex_enter(&mp->mp_mtx);
/*
* Schedule a task function which will try and acquire the mutex via
* mutex_tryenter() while it's held. This should fail and the task
* function will indicate this status in the passed private data.
*/
mp->mp_rc = -EINVAL;
id = taskq_dispatch(tq, splat_mutex_test1_func, mp, TQ_SLEEP);
if (id == 0) {
mutex_exit(&mp->mp_mtx);
splat_vprint(file, SPLAT_MUTEX_TEST1_NAME, "%s",
"taskq_dispatch() failed\n");
rc = -EINVAL;
goto out;
}
/*
* Schedule a task function which will try and acquire the mutex via
* mutex_tryenter() while it's held. This should fail and the task
* function will indicate this status in the passed private data.
*/
mp->mp_rc = -EINVAL;
id = taskq_dispatch(tq, splat_mutex_test1_func, mp, TQ_SLEEP);
if (id == 0) {
mutex_exit(&mp->mp_mtx);
splat_vprint(file, SPLAT_MUTEX_TEST1_NAME, "%s",
"taskq_dispatch() failed\n");
rc = -EINVAL;
goto out;
}
taskq_wait_id(tq, id);
mutex_exit(&mp->mp_mtx);
taskq_wait_id(tq, id);
mutex_exit(&mp->mp_mtx);
/* Task function successfully acquired mutex, very bad! */
if (mp->mp_rc != -EBUSY) {
splat_vprint(file, SPLAT_MUTEX_TEST1_NAME,
"mutex_trylock() incorrectly succeeded when "
"the mutex was held, %d/%d\n", id, mp->mp_rc);
rc = -EINVAL;
goto out;
} else {
splat_vprint(file, SPLAT_MUTEX_TEST1_NAME, "%s",
"mutex_trylock() correctly failed when "
"the mutex was held\n");
}
/* Task function successfully acquired mutex, very bad! */
if (mp->mp_rc != -EBUSY) {
splat_vprint(file, SPLAT_MUTEX_TEST1_NAME,
"mutex_trylock() incorrectly succeeded when "
"the mutex was held, %d/%d\n", id, mp->mp_rc);
rc = -EINVAL;
goto out;
} else {
splat_vprint(file, SPLAT_MUTEX_TEST1_NAME, "%s",
"mutex_trylock() correctly failed when "
"the mutex was held\n");
}
/*
* Schedule a task function which will try and acquire the mutex via
* mutex_tryenter() while it is not held. This should succeed and
* can be verified by checking the private data.
*/
mp->mp_rc = -EINVAL;
id = taskq_dispatch(tq, splat_mutex_test1_func, mp, TQ_SLEEP);
if (id == 0) {
splat_vprint(file, SPLAT_MUTEX_TEST1_NAME, "%s",
"taskq_dispatch() failed\n");
rc = -EINVAL;
goto out;
}
/*
* Schedule a task function which will try and acquire the mutex via
* mutex_tryenter() while it is not held. This should succeed and
* can be verified by checking the private data.
*/
mp->mp_rc = -EINVAL;
id = taskq_dispatch(tq, splat_mutex_test1_func, mp, TQ_SLEEP);
if (id == 0) {
splat_vprint(file, SPLAT_MUTEX_TEST1_NAME, "%s",
"taskq_dispatch() failed\n");
rc = -EINVAL;
goto out;
}
taskq_wait_id(tq, id);
taskq_wait_id(tq, id);
/* Task function failed to acquire mutex, very bad! */
if (mp->mp_rc != 0) {
splat_vprint(file, SPLAT_MUTEX_TEST1_NAME,
"mutex_trylock() incorrectly failed when "
"the mutex was not held, %d/%d\n", id, mp->mp_rc);
rc = -EINVAL;
} else {
splat_vprint(file, SPLAT_MUTEX_TEST1_NAME, "%s",
"mutex_trylock() correctly succeeded "
"when the mutex was not held\n");
}
/* Task function failed to acquire mutex, very bad! */
if (mp->mp_rc != 0) {
splat_vprint(file, SPLAT_MUTEX_TEST1_NAME,
"mutex_trylock() incorrectly failed when "
"the mutex was not held, %d/%d\n", id, mp->mp_rc);
rc = -EINVAL;
} else {
splat_vprint(file, SPLAT_MUTEX_TEST1_NAME, "%s",
"mutex_trylock() correctly succeeded "
"when the mutex was not held\n");
}
out:
taskq_destroy(tq);
mutex_destroy(&(mp->mp_mtx));
taskq_destroy(tq);
mutex_destroy(&(mp->mp_mtx));
out2:
kfree(mp);
return rc;
kfree(mp);
return rc;
}
static void
splat_mutex_test2_func(void *arg)
{
mutex_priv_t *mp = (mutex_priv_t *)arg;
int rc;
ASSERT(mp->mp_magic == SPLAT_MUTEX_TEST_MAGIC);
mutex_priv_t *mp = (mutex_priv_t *)arg;
int rc;
ASSERT(mp->mp_magic == SPLAT_MUTEX_TEST_MAGIC);
/* Read the value before sleeping and write it after we wake up to
* maximize the chance of a race if mutexs are not working properly */
mutex_enter(&mp->mp_mtx);
rc = mp->mp_rc;
set_current_state(TASK_INTERRUPTIBLE);
schedule_timeout(HZ / 100); /* 1/100 of a second */
VERIFY(mp->mp_rc == rc);
mp->mp_rc = rc + 1;
mutex_exit(&mp->mp_mtx);
/* Read the value before sleeping and write it after we wake up to
* maximize the chance of a race if mutexs are not working properly */
mutex_enter(&mp->mp_mtx);
rc = mp->mp_rc;
set_current_state(TASK_INTERRUPTIBLE);
schedule_timeout(HZ / 100); /* 1/100 of a second */
VERIFY(mp->mp_rc == rc);
mp->mp_rc = rc + 1;
mutex_exit(&mp->mp_mtx);
}
static int
splat_mutex_test2(struct file *file, void *arg)
{
mutex_priv_t *mp;
taskq_t *tq;
int i, rc = 0;
mutex_priv_t *mp;
taskq_t *tq;
int i, rc = 0;
mp = (mutex_priv_t *)kmalloc(sizeof(*mp), GFP_KERNEL);
if (mp == NULL)
return -ENOMEM;
mp = (mutex_priv_t *)kmalloc(sizeof(*mp), GFP_KERNEL);
if (mp == NULL)
return -ENOMEM;
/* Create several threads allowing tasks to race with each other */
tq = taskq_create(SPLAT_MUTEX_TEST_TASKQ, num_online_cpus(),
maxclsyspri, 50, INT_MAX, TASKQ_PREPOPULATE);
if (tq == NULL) {
rc = -ENOMEM;
goto out;
}
/* Create several threads allowing tasks to race with each other */
tq = taskq_create(SPLAT_MUTEX_TEST_TASKQ, num_online_cpus(),
maxclsyspri, 50, INT_MAX, TASKQ_PREPOPULATE);
if (tq == NULL) {
rc = -ENOMEM;
goto out;
}
mp->mp_magic = SPLAT_MUTEX_TEST_MAGIC;
mp->mp_file = file;
mutex_init(&(mp->mp_mtx), SPLAT_MUTEX_TEST_NAME, MUTEX_DEFAULT, NULL);
mp->mp_rc = 0;
mp->mp_magic = SPLAT_MUTEX_TEST_MAGIC;
mp->mp_file = file;
mutex_init(&(mp->mp_mtx), SPLAT_MUTEX_TEST_NAME, MUTEX_DEFAULT, NULL);
mp->mp_rc = 0;
/*
* Schedule N work items to the work queue each of which enters the
* mutex, sleeps briefly, then exits the mutex. On a multiprocessor
* box these work items will be handled by all available CPUs. The
* task function checks to ensure the tracked shared variable is
* always only incremented by one. Additionally, the mutex itself
* is instrumented such that if any two processors are in the
* critical region at the same time the system will panic. If the
* mutex is implemented right this will never happy, that's a pass.
*/
for (i = 0; i < SPLAT_MUTEX_TEST_COUNT; i++) {
if (!taskq_dispatch(tq, splat_mutex_test2_func, mp, TQ_SLEEP)) {
splat_vprint(file, SPLAT_MUTEX_TEST2_NAME,
"Failed to queue task %d\n", i);
rc = -EINVAL;
}
}
/*
* Schedule N work items to the work queue each of which enters the
* mutex, sleeps briefly, then exits the mutex. On a multiprocessor
* box these work items will be handled by all available CPUs. The
* task function checks to ensure the tracked shared variable is
* always only incremented by one. Additionally, the mutex itself
* is instrumented such that if any two processors are in the
* critical region at the same time the system will panic. If the
* mutex is implemented right this will never happy, that's a pass.
*/
for (i = 0; i < SPLAT_MUTEX_TEST_COUNT; i++) {
if (!taskq_dispatch(tq, splat_mutex_test2_func, mp, TQ_SLEEP)) {
splat_vprint(file, SPLAT_MUTEX_TEST2_NAME,
"Failed to queue task %d\n", i);
rc = -EINVAL;
}
}
taskq_wait(tq);
taskq_wait(tq);
if (mp->mp_rc == SPLAT_MUTEX_TEST_COUNT) {
splat_vprint(file, SPLAT_MUTEX_TEST2_NAME, "%d racing threads "
"correctly entered/exited the mutex %d times\n",
num_online_cpus(), mp->mp_rc);
} else {
splat_vprint(file, SPLAT_MUTEX_TEST2_NAME, "%d racing threads "
"only processed %d/%d mutex work items\n",
num_online_cpus(),mp->mp_rc,SPLAT_MUTEX_TEST_COUNT);
rc = -EINVAL;
}
if (mp->mp_rc == SPLAT_MUTEX_TEST_COUNT) {
splat_vprint(file, SPLAT_MUTEX_TEST2_NAME, "%d racing threads "
"correctly entered/exited the mutex %d times\n",
num_online_cpus(), mp->mp_rc);
} else {
splat_vprint(file, SPLAT_MUTEX_TEST2_NAME, "%d racing threads "
"only processed %d/%d mutex work items\n",
num_online_cpus(),mp->mp_rc,SPLAT_MUTEX_TEST_COUNT);
rc = -EINVAL;
}
taskq_destroy(tq);
mutex_destroy(&(mp->mp_mtx));
taskq_destroy(tq);
mutex_destroy(&(mp->mp_mtx));
out:
kfree(mp);
return rc;
kfree(mp);
return rc;
}
static int
splat_mutex_test3(struct file *file, void *arg)
{
kmutex_t mtx;
int rc = 0;
int rc = 0;
mutex_init(&mtx, SPLAT_MUTEX_TEST_NAME, MUTEX_DEFAULT, NULL);
mutex_init(&mtx, SPLAT_MUTEX_TEST_NAME, MUTEX_DEFAULT, NULL);
mutex_enter(&mtx);
mutex_enter(&mtx);
/* Mutex should be owned by current */
if (!mutex_owned(&mtx)) {
splat_vprint(file, SPLAT_MUTEX_TEST3_NAME, "Unowned mutex "
"should be owned by pid %d\n", current->pid);
rc = -EINVAL;
goto out;
}
/* Mutex should be owned by current */
if (!mutex_owned(&mtx)) {
splat_vprint(file, SPLAT_MUTEX_TEST3_NAME, "Mutex should "
"be owned by pid %d but is owned by pid %d\n",
current->pid, mtx.km_owner ? mtx.km_owner->pid : -1);
rc = -EINVAL;
goto out;
}
mutex_exit(&mtx);
mutex_exit(&mtx);
/* Mutex should not be owned by any task */
if (mutex_owned(&mtx)) {
splat_vprint(file, SPLAT_MUTEX_TEST3_NAME, "Mutex should "
"not be owned but is owned by pid %d\n",
mtx.km_owner ? mtx.km_owner->pid : -1);
rc = -EINVAL;
goto out;
}
/* Mutex should not be owned by any task */
if (mutex_owned(&mtx)) {
splat_vprint(file, SPLAT_MUTEX_TEST3_NAME, "Mutex owned by "
"pid %d should be unowned\b", current->pid);
rc = -EINVAL;
goto out;
}
splat_vprint(file, SPLAT_MUTEX_TEST3_NAME, "%s",
"Correct mutex_owned() behavior\n");
"Correct mutex_owned() behavior\n");
out:
mutex_destroy(&mtx);
mutex_destroy(&mtx);
return rc;
return rc;
}
static int
splat_mutex_test4(struct file *file, void *arg)
{
kmutex_t mtx;
kthread_t *owner;
int rc = 0;
kthread_t *owner;
int rc = 0;
mutex_init(&mtx, SPLAT_MUTEX_TEST_NAME, MUTEX_DEFAULT, NULL);
mutex_init(&mtx, SPLAT_MUTEX_TEST_NAME, MUTEX_DEFAULT, NULL);
mutex_enter(&mtx);
mutex_enter(&mtx);
/* Mutex should be owned by current */
owner = mutex_owner(&mtx);
if (current != owner) {
splat_vprint(file, SPLAT_MUTEX_TEST3_NAME, "Mutex should "
"be owned by pid %d but is owned by pid %d\n",
current->pid, owner ? owner->pid : -1);
rc = -EINVAL;
goto out;
}
/* Mutex should be owned by current */
owner = mutex_owner(&mtx);
if (current != owner) {
splat_vprint(file, SPLAT_MUTEX_TEST3_NAME, "Mutex should "
"be owned by pid %d but is owned by pid %d\n",
current->pid, owner ? owner->pid : -1);
rc = -EINVAL;
goto out;
}
mutex_exit(&mtx);
mutex_exit(&mtx);
/* Mutex should not be owned by any task */
owner = mutex_owner(&mtx);
if (owner) {
splat_vprint(file, SPLAT_MUTEX_TEST3_NAME, "Mutex should not "
"be owned but is owned by pid %d\n", owner->pid);
rc = -EINVAL;
goto out;
}
/* Mutex should not be owned by any task */
owner = mutex_owner(&mtx);
if (owner) {
splat_vprint(file, SPLAT_MUTEX_TEST3_NAME, "Mutex should not "
"be owned but is owned by pid %d\n", owner->pid);
rc = -EINVAL;
goto out;
}
splat_vprint(file, SPLAT_MUTEX_TEST3_NAME, "%s",
"Correct mutex_owner() behavior\n");
"Correct mutex_owner() behavior\n");
out:
mutex_destroy(&mtx);
mutex_destroy(&mtx);
return rc;
return rc;
}
splat_subsystem_t *

6
spl_config.h.in
View File

@ -9,9 +9,6 @@
/* Define to 1 to enable kstat debugging */
#undef DEBUG_KSTAT
/* Define to 1 to enable mutex debugging */
#undef DEBUG_MUTEX
/* register_sysctl_table() wants 2 args */
#undef HAVE_2ARGS_REGISTER_SYSCTL
@ -102,6 +99,9 @@
/* mutex_lock_nested() is available */
#undef HAVE_MUTEX_LOCK_NESTED
/* struct mutex has owner */
#undef HAVE_MUTEX_OWNER
/* next_online_pgdat() is available */
#undef HAVE_NEXT_ONLINE_PGDAT