* [Qemu-devel] [PATCH] coroutine: drop GThread coroutine backend
@ 2016-01-29 16:07 Stefan Hajnoczi
2016-01-29 16:41 ` Alex Bennée
2016-02-02 17:29 ` Stefan Hajnoczi
0 siblings, 2 replies; 6+ messages in thread
From: Stefan Hajnoczi @ 2016-01-29 16:07 UTC (permalink / raw)
To: qemu-devel; +Cc: Kevin Wolf, Peter Maydell, Alex Bennée, Stefan Hajnoczi
The GThread coroutine backend was a portable coroutine implementation.
Over the years all platforms got their own optimized coroutine
implementations and nothing uses the GThread backend anymore.
In fact, ./configure mentions the GThread backend doesn't work but might
be useful for debugging. Since GDB macros were added to ease debugging
of ucontext coroutines, there seems little point in keeping a broken
backend around.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
configure | 19 ++---
util/coroutine-gthread.c | 198 -----------------------------------------------
2 files changed, 5 insertions(+), 212 deletions(-)
delete mode 100644 util/coroutine-gthread.c
diff --git a/configure b/configure
index 3506e44..789fd7d 100755
--- a/configure
+++ b/configure
@@ -1322,7 +1322,7 @@ Advanced options (experts only):
--oss-lib path to OSS library
--cpu=CPU Build for host CPU [$cpu]
--with-coroutine=BACKEND coroutine backend. Supported options:
- gthread, ucontext, sigaltstack, windows
+ ucontext, sigaltstack, windows
--enable-gcov enable test coverage analysis with gcov
--gcov=GCOV use specified gcov [$gcov_tool]
--disable-blobs disable installing provided firmware blobs
@@ -4314,10 +4314,8 @@ fi
# check and set a backend for coroutine
# We prefer ucontext, but it's not always possible. The fallback
-# is sigcontext. gthread is not selectable except explicitly, because
-# it is not functional enough to run QEMU proper. (It is occasionally
-# useful for debugging purposes.) On Windows the only valid backend
-# is the Windows-specific one.
+# is sigcontext. On Windows the only valid backend is the Windows-specific
+# one.
ucontext_works=no
if test "$darwin" != "yes"; then
@@ -4356,7 +4354,7 @@ else
feature_not_found "ucontext"
fi
;;
- gthread|sigaltstack)
+ sigaltstack)
if test "$mingw32" = "yes"; then
error_exit "only the 'windows' coroutine backend is valid for Windows"
fi
@@ -4368,14 +4366,7 @@ else
fi
if test "$coroutine_pool" = ""; then
- if test "$coroutine" = "gthread"; then
- coroutine_pool=no
- else
- coroutine_pool=yes
- fi
-fi
-if test "$coroutine" = "gthread" -a "$coroutine_pool" = "yes"; then
- error_exit "'gthread' coroutine backend does not support pool (use --disable-coroutine-pool)"
+ coroutine_pool=yes
fi
##########################################
diff --git a/util/coroutine-gthread.c b/util/coroutine-gthread.c
deleted file mode 100644
index 0bcd778..0000000
--- a/util/coroutine-gthread.c
+++ /dev/null
@@ -1,198 +0,0 @@
-/*
- * GThread coroutine initialization code
- *
- * Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>
- * Copyright (C) 2011 Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.0 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, see <http://www.gnu.org/licenses/>.
- */
-
-#include <glib.h>
-#include "qemu-common.h"
-#include "qemu/coroutine_int.h"
-
-typedef struct {
- Coroutine base;
- GThread *thread;
- bool runnable;
- bool free_on_thread_exit;
- CoroutineAction action;
-} CoroutineGThread;
-
-static CompatGMutex coroutine_lock;
-static CompatGCond coroutine_cond;
-
-/* GLib 2.31 and beyond deprecated various parts of the thread API,
- * but the new interfaces are not available in older GLib versions
- * so we have to cope with both.
- */
-#if GLIB_CHECK_VERSION(2, 31, 0)
-/* Awkwardly, the GPrivate API doesn't provide a way to update the
- * GDestroyNotify handler for the coroutine key dynamically. So instead
- * we track whether or not the CoroutineGThread should be freed on
- * thread exit / coroutine key update using the free_on_thread_exit
- * field.
- */
-static void coroutine_destroy_notify(gpointer data)
-{
- CoroutineGThread *co = data;
- if (co && co->free_on_thread_exit) {
- g_free(co);
- }
-}
-
-static GPrivate coroutine_key = G_PRIVATE_INIT(coroutine_destroy_notify);
-
-static inline CoroutineGThread *get_coroutine_key(void)
-{
- return g_private_get(&coroutine_key);
-}
-
-static inline void set_coroutine_key(CoroutineGThread *co,
- bool free_on_thread_exit)
-{
- /* Unlike g_static_private_set() this does not call the GDestroyNotify
- * if the previous value of the key was NULL. Fortunately we only need
- * the GDestroyNotify in the non-NULL key case.
- */
- co->free_on_thread_exit = free_on_thread_exit;
- g_private_replace(&coroutine_key, co);
-}
-
-static inline GThread *create_thread(GThreadFunc func, gpointer data)
-{
- return g_thread_new("coroutine", func, data);
-}
-
-#else
-
-/* Handle older GLib versions */
-
-static GStaticPrivate coroutine_key = G_STATIC_PRIVATE_INIT;
-
-static inline CoroutineGThread *get_coroutine_key(void)
-{
- return g_static_private_get(&coroutine_key);
-}
-
-static inline void set_coroutine_key(CoroutineGThread *co,
- bool free_on_thread_exit)
-{
- g_static_private_set(&coroutine_key, co,
- free_on_thread_exit ? (GDestroyNotify)g_free : NULL);
-}
-
-static inline GThread *create_thread(GThreadFunc func, gpointer data)
-{
- return g_thread_create_full(func, data, 0, TRUE, TRUE,
- G_THREAD_PRIORITY_NORMAL, NULL);
-}
-
-#endif
-
-
-static void __attribute__((constructor)) coroutine_init(void)
-{
-#if !GLIB_CHECK_VERSION(2, 31, 0)
- if (!g_thread_supported()) {
- g_thread_init(NULL);
- }
-#endif
-}
-
-static void coroutine_wait_runnable_locked(CoroutineGThread *co)
-{
- while (!co->runnable) {
- g_cond_wait(&coroutine_cond, &coroutine_lock);
- }
-}
-
-static void coroutine_wait_runnable(CoroutineGThread *co)
-{
- g_mutex_lock(&coroutine_lock);
- coroutine_wait_runnable_locked(co);
- g_mutex_unlock(&coroutine_lock);
-}
-
-static gpointer coroutine_thread(gpointer opaque)
-{
- CoroutineGThread *co = opaque;
-
- set_coroutine_key(co, false);
- coroutine_wait_runnable(co);
- co->base.entry(co->base.entry_arg);
- qemu_coroutine_switch(&co->base, co->base.caller, COROUTINE_TERMINATE);
- return NULL;
-}
-
-Coroutine *qemu_coroutine_new(void)
-{
- CoroutineGThread *co;
-
- co = g_malloc0(sizeof(*co));
- co->thread = create_thread(coroutine_thread, co);
- if (!co->thread) {
- g_free(co);
- return NULL;
- }
- return &co->base;
-}
-
-void qemu_coroutine_delete(Coroutine *co_)
-{
- CoroutineGThread *co = DO_UPCAST(CoroutineGThread, base, co_);
-
- g_thread_join(co->thread);
- g_free(co);
-}
-
-CoroutineAction qemu_coroutine_switch(Coroutine *from_,
- Coroutine *to_,
- CoroutineAction action)
-{
- CoroutineGThread *from = DO_UPCAST(CoroutineGThread, base, from_);
- CoroutineGThread *to = DO_UPCAST(CoroutineGThread, base, to_);
-
- g_mutex_lock(&coroutine_lock);
- from->runnable = false;
- from->action = action;
- to->runnable = true;
- to->action = action;
- g_cond_broadcast(&coroutine_cond);
-
- if (action != COROUTINE_TERMINATE) {
- coroutine_wait_runnable_locked(from);
- }
- g_mutex_unlock(&coroutine_lock);
- return from->action;
-}
-
-Coroutine *qemu_coroutine_self(void)
-{
- CoroutineGThread *co = get_coroutine_key();
- if (!co) {
- co = g_malloc0(sizeof(*co));
- co->runnable = true;
- set_coroutine_key(co, true);
- }
-
- return &co->base;
-}
-
-bool qemu_in_coroutine(void)
-{
- CoroutineGThread *co = get_coroutine_key();
-
- return co && co->base.caller;
-}
--
2.5.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH] coroutine: drop GThread coroutine backend
2016-01-29 16:07 [Qemu-devel] [PATCH] coroutine: drop GThread coroutine backend Stefan Hajnoczi
@ 2016-01-29 16:41 ` Alex Bennée
2016-02-01 11:37 ` Stefan Hajnoczi
2016-02-02 17:29 ` Stefan Hajnoczi
1 sibling, 1 reply; 6+ messages in thread
From: Alex Bennée @ 2016-01-29 16:41 UTC (permalink / raw)
To: Stefan Hajnoczi; +Cc: Kevin Wolf, Peter Maydell, qemu-devel
Stefan Hajnoczi <stefanha@redhat.com> writes:
> The GThread coroutine backend was a portable coroutine implementation.
> Over the years all platforms got their own optimized coroutine
> implementations and nothing uses the GThread backend anymore.
>
> In fact, ./configure mentions the GThread backend doesn't work but might
> be useful for debugging. Since GDB macros were added to ease debugging
> of ucontext coroutines, there seems little point in keeping a broken
> backend around.
Except I found that I couldn't run the ThreadSanitizer without using the
gthread co-routines. So while I totally agree we should dump stuff
that's not used lets make sure no one else relies on it for debugging
stuff as well.
>
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
> configure | 19 ++---
> util/coroutine-gthread.c | 198 -----------------------------------------------
> 2 files changed, 5 insertions(+), 212 deletions(-)
> delete mode 100644 util/coroutine-gthread.c
>
> diff --git a/configure b/configure
> index 3506e44..789fd7d 100755
> --- a/configure
> +++ b/configure
> @@ -1322,7 +1322,7 @@ Advanced options (experts only):
> --oss-lib path to OSS library
> --cpu=CPU Build for host CPU [$cpu]
> --with-coroutine=BACKEND coroutine backend. Supported options:
> - gthread, ucontext, sigaltstack, windows
> + ucontext, sigaltstack, windows
> --enable-gcov enable test coverage analysis with gcov
> --gcov=GCOV use specified gcov [$gcov_tool]
> --disable-blobs disable installing provided firmware blobs
> @@ -4314,10 +4314,8 @@ fi
> # check and set a backend for coroutine
>
> # We prefer ucontext, but it's not always possible. The fallback
> -# is sigcontext. gthread is not selectable except explicitly, because
> -# it is not functional enough to run QEMU proper. (It is occasionally
> -# useful for debugging purposes.) On Windows the only valid backend
> -# is the Windows-specific one.
> +# is sigcontext. On Windows the only valid backend is the Windows-specific
> +# one.
>
> ucontext_works=no
> if test "$darwin" != "yes"; then
> @@ -4356,7 +4354,7 @@ else
> feature_not_found "ucontext"
> fi
> ;;
> - gthread|sigaltstack)
> + sigaltstack)
> if test "$mingw32" = "yes"; then
> error_exit "only the 'windows' coroutine backend is valid for Windows"
> fi
> @@ -4368,14 +4366,7 @@ else
> fi
>
> if test "$coroutine_pool" = ""; then
> - if test "$coroutine" = "gthread"; then
> - coroutine_pool=no
> - else
> - coroutine_pool=yes
> - fi
> -fi
> -if test "$coroutine" = "gthread" -a "$coroutine_pool" = "yes"; then
> - error_exit "'gthread' coroutine backend does not support pool (use --disable-coroutine-pool)"
> + coroutine_pool=yes
> fi
>
> ##########################################
> diff --git a/util/coroutine-gthread.c b/util/coroutine-gthread.c
> deleted file mode 100644
> index 0bcd778..0000000
> --- a/util/coroutine-gthread.c
> +++ /dev/null
> @@ -1,198 +0,0 @@
> -/*
> - * GThread coroutine initialization code
> - *
> - * Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>
> - * Copyright (C) 2011 Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> - *
> - * This library is free software; you can redistribute it and/or
> - * modify it under the terms of the GNU Lesser General Public
> - * License as published by the Free Software Foundation; either
> - * version 2.0 of the License, or (at your option) any later version.
> - *
> - * This library is distributed in the hope that it will be useful,
> - * but WITHOUT ANY WARRANTY; without even the implied warranty of
> - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> - * Lesser General Public License for more details.
> - *
> - * You should have received a copy of the GNU Lesser General Public
> - * License along with this library; if not, see <http://www.gnu.org/licenses/>.
> - */
> -
> -#include <glib.h>
> -#include "qemu-common.h"
> -#include "qemu/coroutine_int.h"
> -
> -typedef struct {
> - Coroutine base;
> - GThread *thread;
> - bool runnable;
> - bool free_on_thread_exit;
> - CoroutineAction action;
> -} CoroutineGThread;
> -
> -static CompatGMutex coroutine_lock;
> -static CompatGCond coroutine_cond;
> -
> -/* GLib 2.31 and beyond deprecated various parts of the thread API,
> - * but the new interfaces are not available in older GLib versions
> - * so we have to cope with both.
> - */
> -#if GLIB_CHECK_VERSION(2, 31, 0)
> -/* Awkwardly, the GPrivate API doesn't provide a way to update the
> - * GDestroyNotify handler for the coroutine key dynamically. So instead
> - * we track whether or not the CoroutineGThread should be freed on
> - * thread exit / coroutine key update using the free_on_thread_exit
> - * field.
> - */
> -static void coroutine_destroy_notify(gpointer data)
> -{
> - CoroutineGThread *co = data;
> - if (co && co->free_on_thread_exit) {
> - g_free(co);
> - }
> -}
> -
> -static GPrivate coroutine_key = G_PRIVATE_INIT(coroutine_destroy_notify);
> -
> -static inline CoroutineGThread *get_coroutine_key(void)
> -{
> - return g_private_get(&coroutine_key);
> -}
> -
> -static inline void set_coroutine_key(CoroutineGThread *co,
> - bool free_on_thread_exit)
> -{
> - /* Unlike g_static_private_set() this does not call the GDestroyNotify
> - * if the previous value of the key was NULL. Fortunately we only need
> - * the GDestroyNotify in the non-NULL key case.
> - */
> - co->free_on_thread_exit = free_on_thread_exit;
> - g_private_replace(&coroutine_key, co);
> -}
> -
> -static inline GThread *create_thread(GThreadFunc func, gpointer data)
> -{
> - return g_thread_new("coroutine", func, data);
> -}
> -
> -#else
> -
> -/* Handle older GLib versions */
> -
> -static GStaticPrivate coroutine_key = G_STATIC_PRIVATE_INIT;
> -
> -static inline CoroutineGThread *get_coroutine_key(void)
> -{
> - return g_static_private_get(&coroutine_key);
> -}
> -
> -static inline void set_coroutine_key(CoroutineGThread *co,
> - bool free_on_thread_exit)
> -{
> - g_static_private_set(&coroutine_key, co,
> - free_on_thread_exit ? (GDestroyNotify)g_free : NULL);
> -}
> -
> -static inline GThread *create_thread(GThreadFunc func, gpointer data)
> -{
> - return g_thread_create_full(func, data, 0, TRUE, TRUE,
> - G_THREAD_PRIORITY_NORMAL, NULL);
> -}
> -
> -#endif
> -
> -
> -static void __attribute__((constructor)) coroutine_init(void)
> -{
> -#if !GLIB_CHECK_VERSION(2, 31, 0)
> - if (!g_thread_supported()) {
> - g_thread_init(NULL);
> - }
> -#endif
> -}
> -
> -static void coroutine_wait_runnable_locked(CoroutineGThread *co)
> -{
> - while (!co->runnable) {
> - g_cond_wait(&coroutine_cond, &coroutine_lock);
> - }
> -}
> -
> -static void coroutine_wait_runnable(CoroutineGThread *co)
> -{
> - g_mutex_lock(&coroutine_lock);
> - coroutine_wait_runnable_locked(co);
> - g_mutex_unlock(&coroutine_lock);
> -}
> -
> -static gpointer coroutine_thread(gpointer opaque)
> -{
> - CoroutineGThread *co = opaque;
> -
> - set_coroutine_key(co, false);
> - coroutine_wait_runnable(co);
> - co->base.entry(co->base.entry_arg);
> - qemu_coroutine_switch(&co->base, co->base.caller, COROUTINE_TERMINATE);
> - return NULL;
> -}
> -
> -Coroutine *qemu_coroutine_new(void)
> -{
> - CoroutineGThread *co;
> -
> - co = g_malloc0(sizeof(*co));
> - co->thread = create_thread(coroutine_thread, co);
> - if (!co->thread) {
> - g_free(co);
> - return NULL;
> - }
> - return &co->base;
> -}
> -
> -void qemu_coroutine_delete(Coroutine *co_)
> -{
> - CoroutineGThread *co = DO_UPCAST(CoroutineGThread, base, co_);
> -
> - g_thread_join(co->thread);
> - g_free(co);
> -}
> -
> -CoroutineAction qemu_coroutine_switch(Coroutine *from_,
> - Coroutine *to_,
> - CoroutineAction action)
> -{
> - CoroutineGThread *from = DO_UPCAST(CoroutineGThread, base, from_);
> - CoroutineGThread *to = DO_UPCAST(CoroutineGThread, base, to_);
> -
> - g_mutex_lock(&coroutine_lock);
> - from->runnable = false;
> - from->action = action;
> - to->runnable = true;
> - to->action = action;
> - g_cond_broadcast(&coroutine_cond);
> -
> - if (action != COROUTINE_TERMINATE) {
> - coroutine_wait_runnable_locked(from);
> - }
> - g_mutex_unlock(&coroutine_lock);
> - return from->action;
> -}
> -
> -Coroutine *qemu_coroutine_self(void)
> -{
> - CoroutineGThread *co = get_coroutine_key();
> - if (!co) {
> - co = g_malloc0(sizeof(*co));
> - co->runnable = true;
> - set_coroutine_key(co, true);
> - }
> -
> - return &co->base;
> -}
> -
> -bool qemu_in_coroutine(void)
> -{
> - CoroutineGThread *co = get_coroutine_key();
> -
> - return co && co->base.caller;
> -}
--
Alex Bennée
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH] coroutine: drop GThread coroutine backend
2016-01-29 16:41 ` Alex Bennée
@ 2016-02-01 11:37 ` Stefan Hajnoczi
2016-02-01 12:17 ` Alex Bennée
0 siblings, 1 reply; 6+ messages in thread
From: Stefan Hajnoczi @ 2016-02-01 11:37 UTC (permalink / raw)
To: Alex Bennée; +Cc: Kevin Wolf, Peter Maydell, qemu-devel
[-- Attachment #1: Type: text/plain, Size: 918 bytes --]
On Fri, Jan 29, 2016 at 04:41:41PM +0000, Alex Bennée wrote:
>
> Stefan Hajnoczi <stefanha@redhat.com> writes:
>
> > The GThread coroutine backend was a portable coroutine implementation.
> > Over the years all platforms got their own optimized coroutine
> > implementations and nothing uses the GThread backend anymore.
> >
> > In fact, ./configure mentions the GThread backend doesn't work but might
> > be useful for debugging. Since GDB macros were added to ease debugging
> > of ucontext coroutines, there seems little point in keeping a broken
> > backend around.
>
> Except I found that I couldn't run the ThreadSanitizer without using the
> gthread co-routines. So while I totally agree we should dump stuff
> that's not used lets make sure no one else relies on it for debugging
> stuff as well.
Is it still the case that ThreadSanitizer only works with gthread
coroutines?
Stefan
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^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH] coroutine: drop GThread coroutine backend
2016-02-01 11:37 ` Stefan Hajnoczi
@ 2016-02-01 12:17 ` Alex Bennée
2016-02-02 17:29 ` Stefan Hajnoczi
0 siblings, 1 reply; 6+ messages in thread
From: Alex Bennée @ 2016-02-01 12:17 UTC (permalink / raw)
To: Stefan Hajnoczi; +Cc: Kevin Wolf, Peter Maydell, qemu-devel
Stefan Hajnoczi <stefanha@redhat.com> writes:
> On Fri, Jan 29, 2016 at 04:41:41PM +0000, Alex Bennée wrote:
>>
>> Stefan Hajnoczi <stefanha@redhat.com> writes:
>>
>> > The GThread coroutine backend was a portable coroutine implementation.
>> > Over the years all platforms got their own optimized coroutine
>> > implementations and nothing uses the GThread backend anymore.
>> >
>> > In fact, ./configure mentions the GThread backend doesn't work but might
>> > be useful for debugging. Since GDB macros were added to ease debugging
>> > of ucontext coroutines, there seems little point in keeping a broken
>> > backend around.
>>
>> Except I found that I couldn't run the ThreadSanitizer without using the
>> gthread co-routines. So while I totally agree we should dump stuff
>> that's not used lets make sure no one else relies on it for debugging
>> stuff as well.
>
> Is it still the case that ThreadSanitizer only works with gthread
> coroutines?
It certainly was very confused about what was going on with the default
option (sigucontext IIRC?).
>
> Stefan
--
Alex Bennée
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH] coroutine: drop GThread coroutine backend
2016-02-01 12:17 ` Alex Bennée
@ 2016-02-02 17:29 ` Stefan Hajnoczi
0 siblings, 0 replies; 6+ messages in thread
From: Stefan Hajnoczi @ 2016-02-02 17:29 UTC (permalink / raw)
To: Alex Bennée; +Cc: Kevin Wolf, Peter Maydell, qemu-devel
[-- Attachment #1: Type: text/plain, Size: 1425 bytes --]
On Mon, Feb 01, 2016 at 12:17:14PM +0000, Alex Bennée wrote:
>
> Stefan Hajnoczi <stefanha@redhat.com> writes:
>
> > On Fri, Jan 29, 2016 at 04:41:41PM +0000, Alex Bennée wrote:
> >>
> >> Stefan Hajnoczi <stefanha@redhat.com> writes:
> >>
> >> > The GThread coroutine backend was a portable coroutine implementation.
> >> > Over the years all platforms got their own optimized coroutine
> >> > implementations and nothing uses the GThread backend anymore.
> >> >
> >> > In fact, ./configure mentions the GThread backend doesn't work but might
> >> > be useful for debugging. Since GDB macros were added to ease debugging
> >> > of ucontext coroutines, there seems little point in keeping a broken
> >> > backend around.
> >>
> >> Except I found that I couldn't run the ThreadSanitizer without using the
> >> gthread co-routines. So while I totally agree we should dump stuff
> >> that's not used lets make sure no one else relies on it for debugging
> >> stuff as well.
> >
> > Is it still the case that ThreadSanitizer only works with gthread
> > coroutines?
>
> It certainly was very confused about what was going on with the default
> option (sigucontext IIRC?).
Okay, it looks like there is a good reason to keep the GThread backend.
If I have time I'd like to look into the reason why the GThread backend
doesn't pass "make check". I noticed that ide tests were hanging.
Stefan
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* Re: [Qemu-devel] [PATCH] coroutine: drop GThread coroutine backend
2016-01-29 16:07 [Qemu-devel] [PATCH] coroutine: drop GThread coroutine backend Stefan Hajnoczi
2016-01-29 16:41 ` Alex Bennée
@ 2016-02-02 17:29 ` Stefan Hajnoczi
1 sibling, 0 replies; 6+ messages in thread
From: Stefan Hajnoczi @ 2016-02-02 17:29 UTC (permalink / raw)
To: qemu-devel; +Cc: Kevin Wolf, Peter Maydell, Alex Bennée
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On Fri, Jan 29, 2016 at 04:07:48PM +0000, Stefan Hajnoczi wrote:
> The GThread coroutine backend was a portable coroutine implementation.
> Over the years all platforms got their own optimized coroutine
> implementations and nothing uses the GThread backend anymore.
>
> In fact, ./configure mentions the GThread backend doesn't work but might
> be useful for debugging. Since GDB macros were added to ease debugging
> of ucontext coroutines, there seems little point in keeping a broken
> backend around.
>
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
> configure | 19 ++---
> util/coroutine-gthread.c | 198 -----------------------------------------------
> 2 files changed, 5 insertions(+), 212 deletions(-)
> delete mode 100644 util/coroutine-gthread.c
NACK
Alex Bennee pointed out that ThreadSanitizer needs the GThread backend
because it cannot cope with stack switching.
Stefan
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-- links below jump to the message on this page --
2016-01-29 16:07 [Qemu-devel] [PATCH] coroutine: drop GThread coroutine backend Stefan Hajnoczi
2016-01-29 16:41 ` Alex Bennée
2016-02-01 11:37 ` Stefan Hajnoczi
2016-02-01 12:17 ` Alex Bennée
2016-02-02 17:29 ` Stefan Hajnoczi
2016-02-02 17:29 ` Stefan Hajnoczi
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