On 07/07/2015 14:33, Alex Bennée wrote:
Frederic Konrad <[email protected]> writes:
On 26/06/2015 16:56, Jan Kiszka wrote:
On 2015-06-26 16:47, [email protected] wrote:
From: Jan Kiszka <[email protected]>
This finally allows TCG to benefit from the iothread introduction: Drop
the global mutex while running pure TCG CPU code. Reacquire the lock
when entering MMIO or PIO emulation, or when leaving the TCG loop.
<snip>
diff --git a/translate-all.c b/translate-all.c
index c25b79b..ade2269 100644
--- a/translate-all.c
+++ b/translate-all.c
@@ -1222,6 +1222,7 @@ void tb_invalidate_phys_page_range(tb_page_addr_t start,
tb_page_addr_t end,
#endif
#ifdef TARGET_HAS_PRECISE_SMC
if (current_tb_modified) {
+ qemu_mutex_unlock_iothread();
/* we generate a block containing just the instruction
modifying the memory. It will ensure that it cannot modify
itself */
@@ -1326,6 +1327,7 @@ static void tb_invalidate_phys_page(tb_page_addr_t addr,
p->first_tb = NULL;
#ifdef TARGET_HAS_PRECISE_SMC
if (current_tb_modified) {
+ qemu_mutex_unlock_iothread();
/* we generate a block containing just the instruction
modifying the memory. It will ensure that it cannot modify
itself */
diff --git a/vl.c b/vl.c
index 69ad90c..2983d44 100644
--- a/vl.c
+++ b/vl.c
@@ -1698,10 +1698,16 @@ void qemu_devices_reset(void)
{
QEMUResetEntry *re, *nre;
+ /*
+ * Some device's reset needs to grab the global_mutex. So just release it
+ * here.
That's a property newly introduced by the patch, or how does this
happen? In turn, are all reset handlers now fine to be called outside of
BQL? This looks suspicious, but it's been quite a while since I last
starred at this.
Jan
Hi Jan,
Sorry for that, it's a dirty hack :).
Some reset handler probably load stuff in the memory hence a double lock.
It will probably disappear with:
http://thread.gmane.org/gmane.comp.emulators.qemu/345258
So I guess this patch will shrink a lot once we re-base ontop of Paolo's
patches (which should be real soon now).
Yes exactly.
Thanks,
Fred
+ */
+ qemu_mutex_unlock_iothread();
/* reset all devices */
QTAILQ_FOREACH_SAFE(re, &reset_handlers, entry, nre) {
re->func(re->opaque);
}
+ qemu_mutex_lock_iothread();
}
void qemu_system_reset(bool report)
