[oe-commits] Pratheesh Gangadhar : glib-2.0 2.21.4: add armv6 atomic ops, this fixes 100% utilization hangs when doing DSP based GStreamer playback
git version control
git at git.openembedded.org
Thu Aug 27 14:05:21 UTC 2009
Module: openembedded.git
Branch: org.openembedded.dev
Commit: 1eb89aacbc6830fe242eac36ba8bcb61d98807f5
URL: http://gitweb.openembedded.net/?p=openembedded.git&a=commit;h=1eb89aacbc6830fe242eac36ba8bcb61d98807f5
Author: Pratheesh Gangadhar <pratheesh.gangadhar at gmail.com>
Date: Thu Aug 27 02:51:00 2009 +0530
glib-2.0 2.21.4: add armv6 atomic ops, this fixes 100% utilization hangs when doing DSP based GStreamer playback
GLIB by default uses ARMV5 instructions for emulating atomic operations and this patch (derived from https://stage.maemo.org/svn/maemo/projects/haf/trunk/glib/debian/patches/25-gatomic.patch) make use ARMV6 atomic instructions instead. CPU goes into "sched_yield" while loop during hang - due to a race condition triggered by high rate context switching while running DSP plugins.
---
recipes/glib-2.0/files/gatomic_armv6.patch | 260 ++++++++++++++++++++++++++++
recipes/glib-2.0/glib-2.0_2.21.4.bb | 6 +-
2 files changed, 265 insertions(+), 1 deletions(-)
diff --git a/recipes/glib-2.0/files/gatomic_armv6.patch b/recipes/glib-2.0/files/gatomic_armv6.patch
new file mode 100755
index 0000000..04bae15
--- /dev/null
+++ b/recipes/glib-2.0/files/gatomic_armv6.patch
@@ -0,0 +1,260 @@
+--- glib-2.18.1.orig/configure.in
++++ glib-2.18.1/configure.in
+@@ -2396,9 +2396,15 @@ if test x"$GCC" = xyes; then
+ ;;
+ arm*)
+ AC_MSG_RESULT([arm])
+- AC_DEFINE_UNQUOTED(G_ATOMIC_ARM, 1,
+- [arm atomic implementation])
+- glib_memory_barrier_needed=no
++ AC_MSG_CHECKING(arm atomic operations type)
++ AC_MSG_RESULT(inline asm)
++ AC_DEFINE_UNQUOTED(G_ATOMIC_ARM, 6,
++ [armv6 atomic implementation])
++ glib_memory_barrier_needed=yes
++ dnl AC_MSG_RESULT(kernel helper)
++ dnl AC_DEFINE_UNQUOTED(G_ATOMIC_ARM_LINUX, 1,
++ dnl [special arm linux implementation])
++ dnl glib_memory_barrier_needed=yes
+ ;;
+ *)
+ AC_MSG_RESULT([none])
+--- /tmp/gatomic.c 2009-08-27 02:08:32.000000000 +0530
++++ glib-2.21.4/glib/gatomic.c 2009-08-27 02:08:49.000000000 +0530
+@@ -561,6 +561,7 @@ g_atomic_pointer_compare_and_exchange (v
+ # error "Your system has an unsupported pointer size"
+ # endif /* GLIB_SIZEOF_VOID_P */
+ # elif defined (G_ATOMIC_ARM)
++# if (G_ATOMIC_ARM < 6)
+ static volatile int atomic_spin = 0;
+
+ static int atomic_spin_trylock (void)
+@@ -651,6 +652,218 @@ g_atomic_pointer_compare_and_exchange (v
+
+ return result;
+ }
++ # else /* G_ATOMIC_ARM < 6 */
++ gint
++ g_atomic_int_exchange_and_add (volatile gint *atomic,
++ gint val)
++ {
++ unsigned long result;
++ int old, tmp;
++
++ do {
++ asm volatile (
++ "ldrex %0, [%3]\n"
++ "add %1, %0, %4\n"
++ "strex %2, %1, [%3]\n"
++ : "=&r" (old), "=&r" (tmp), "=&r" (result)
++ : "r" (atomic), "Ir" (val)
++ : "cc", "memory");
++ } while (result);
++ return old;
++ }
++
++ void
++ g_atomic_int_add (volatile gint *atomic,
++ gint val)
++ {
++ unsigned long result;
++ int tmp;
++
++ do {
++ asm volatile (
++ "ldrex %0, [%2]\n"
++ "add %0, %0, %3\n"
++ "strex %1, %0, [%2]\n"
++ : "=&r" (tmp), "=&r" (result)
++ : "r" (atomic), "Ir" (val)
++ : "cc", "memory");
++ } while (result);
++ }
++
++ gboolean
++ g_atomic_int_compare_and_exchange (volatile gint *atomic,
++ gint oldval,
++ gint newval)
++ {
++ unsigned long result;
++ int old;
++
++ asm volatile (
++ "ldrex %1, [%2]\n"
++ "mov %0, #1\n"
++ "teq %1, %3\n"
++ "strexeq %0, %4, [%2]\n"
++ : "=&r" (result), "=&r" (old)
++ : "r" (atomic), "Ir" (oldval), "r" (newval)
++ : "cc", "memory");
++ return (result) ? FALSE : TRUE;
++ }
++
++ gboolean
++ g_atomic_pointer_compare_and_exchange (volatile gpointer *atomic,
++ gpointer oldval,
++ gpointer newval)
++ {
++ unsigned long result;
++ void *old;
++
++ asm volatile (
++ "ldrex %1, [%2]\n"
++ "mov %0, #1\n"
++ "teq %1, %3\n"
++ "strexeq %0, %4, [%2]\n"
++ : "=&r" (result), "=&r" (old)
++ : "r" (atomic), "Ir" (oldval), "r" (newval)
++ : "cc", "memory");
++ return (result) ? FALSE : TRUE;
++ }
++
++ gint
++ (g_atomic_int_get) (volatile gint *atomic)
++ {
++ return *atomic;
++ }
++
++ void
++ (g_atomic_int_set) (volatile gint *atomic,
++ gint newval)
++ {
++ unsigned long result;
++
++ do {
++ asm volatile (
++ "ldrex %0, [%1]\n"
++ "strex %0, %2, [%1]\n"
++ : "=&r" (result)
++ : "r" (atomic), "r" (newval)
++ : "cc", "memory");
++ } while (result);
++ }
++
++ gpointer
++ (g_atomic_pointer_get) (volatile gpointer *atomic)
++ {
++ return *atomic;
++ }
++
++ void
++ (g_atomic_pointer_set) (volatile gpointer *atomic,
++ gpointer newval)
++ {
++ unsigned long result;
++
++ do {
++ asm volatile (
++ "ldrex %0, [%1]\n"
++ "strex %0, %2, [%1]\n"
++ : "=&r" (result)
++ : "r" (atomic), "r" (newval)
++ : "cc", "memory");
++ } while (result);
++ }
++# endif /* G_ATOMIC_ARM < 6 */
++ # elif defined(G_ATOMIC_ARM_LINUX)
++ /* use special helper functions provided by the linux kernel */
++
++ typedef void (_khelper_barrier_t)(void);
++ #define _khelper_barrier (*(_khelper_barrier_t *)0xffff0fa0)
++ #define G_ATOMIC_MEMORY_BARRIER _khelper_barrier()
++ /* scratchbox/qemu explodes on barrier */
++ /*#define G_ATOMIC_MEMORY_BARRIER while(0)*/
++ typedef int (_khelper_cmpxchg_t)(int oldval, int newval, volatile int *ptr);
++ #define _khelper_cmpxchg (*(_khelper_cmpxchg_t *)0xffff0fc0)
++
++ gint
++ g_atomic_int_exchange_and_add (volatile gint *atomic,
++ gint val)
++ {
++ int result;
++ int old, new;
++
++ do {
++ old = *atomic;
++ new = old + val;
++ result = _khelper_cmpxchg(old, new, atomic);
++ } while (result);
++ return old;
++ }
++
++ void
++ g_atomic_int_add (volatile gint *atomic,
++ gint val)
++ {
++ int result;
++ int old, new;
++
++ do {
++ old = *atomic;
++ new = old + val;
++ result = _khelper_cmpxchg(old, new, atomic);
++ } while (result);
++ }
++
++ gboolean
++ g_atomic_int_compare_and_exchange (volatile gint *atomic,
++ gint oldval,
++ gint newval)
++ {
++ int result;
++
++ result = _khelper_cmpxchg(oldval, newval, atomic);
++ return (result) ? FALSE : TRUE;
++ }
++
++ gboolean
++ g_atomic_pointer_compare_and_exchange (volatile gpointer *atomic,
++ gpointer oldval,
++ gpointer newval)
++ {
++ int result;
++
++ result = _khelper_cmpxchg(*((int *) &oldval),
++ *((int *) &newval),
++ (int *) atomic);
++ return (result) ? FALSE : TRUE;
++ }
++
++ gint
++ (g_atomic_int_get) (volatile gint *atomic)
++ {
++ return *atomic;
++ }
++
++ void
++ (g_atomic_int_set) (volatile gint *atomic,
++ gint newval)
++ {
++ while (_khelper_cmpxchg(*atomic, newval, atomic));
++ }
++
++ gpointer
++ (g_atomic_pointer_get) (volatile gpointer *atomic)
++ {
++ return *atomic;
++ }
++
++ void
++ (g_atomic_pointer_set) (volatile gpointer *atomic,
++ gpointer newval)
++ {
++ while (_khelper_cmpxchg(*((int *) atomic),
++ *((int *) &newval),
++ (int *) atomic));
++ }
++
+ # elif defined (G_ATOMIC_CRIS) || defined (G_ATOMIC_CRISV32)
+ # ifdef G_ATOMIC_CRIS
+ # define CRIS_ATOMIC_INT_CMP_XCHG(atomic, oldval, newval) \
+@@ -954,7 +1167,8 @@ void
+ g_mutex_unlock (g_atomic_mutex);
+ }
+ #endif /* G_ATOMIC_OP_MEMORY_BARRIER_NEEDED */
+-#elif defined (G_ATOMIC_OP_MEMORY_BARRIER_NEEDED)
++#elif (defined (G_ATOMIC_OP_MEMORY_BARRIER_NEEDED) && \
++ !defined(G_ATOMIC_ARM) && !defined(G_ATOMIC_ARM_LINUX))
+ gint
+ (g_atomic_int_get) (volatile gint G_GNUC_MAY_ALIAS *atomic)
+ {
diff --git a/recipes/glib-2.0/glib-2.0_2.21.4.bb b/recipes/glib-2.0/glib-2.0_2.21.4.bb
index 4be0949..ca9e4b2 100644
--- a/recipes/glib-2.0/glib-2.0_2.21.4.bb
+++ b/recipes/glib-2.0/glib-2.0_2.21.4.bb
@@ -3,9 +3,13 @@ require glib.inc
DEFAULT_PREFERENCE = "-1"
DEFAULT_PREFERENCE_angstrom = "1"
+PR = "r1"
+
SRC_URI = "\
http://ftp.gnome.org/pub/GNOME/sources/glib/2.21/glib-${PV}.tar.bz2 \
file://glibconfig-sysdefs.h \
file://configure-libtool.patch;patch=1 \
"
-SRC_URI_append_arm = " file://atomic-thumb.patch;patch=1"
+SRC_URI_append_arm = " file://atomic-thumb.patch;patch=1 \
+ file://gatomic_armv6.patch;patch=1 \
+"
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