diff options
| author | Jan Kiszka <jan.kiszka@siemens.com> | 2017-02-23 18:29:11 +0000 |
|---|---|---|
| committer | Alex Bennée <alex.bennee@linaro.org> | 2017-02-24 10:32:45 +0000 |
| commit | 8d04fb55dec381bc5105cb47f29d918e579e8cbd (patch) | |
| tree | 279eb632e33d57c869bae0b70c6261af5d0e854a /target/i386 | |
| parent | 791158d93b27f22a17c2ada06621831d54f09a2c (diff) | |
| download | qemu-8d04fb55dec381bc5105cb47f29d918e579e8cbd.tar.gz | |
tcg: drop global lock during TCG code execution
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.
We have to revert a few optimization for the current TCG threading
model, namely kicking the TCG thread in qemu_mutex_lock_iothread and not
kicking it in qemu_cpu_kick. We also need to disable RAM block
reordering until we have a more efficient locking mechanism at hand.
Still, a Linux x86 UP guest and my Musicpal ARM model boot fine here.
These numbers demonstrate where we gain something:
20338 jan 20 0 331m 75m 6904 R 99 0.9 0:50.95 qemu-system-arm
20337 jan 20 0 331m 75m 6904 S 20 0.9 0:26.50 qemu-system-arm
The guest CPU was fully loaded, but the iothread could still run mostly
independent on a second core. Without the patch we don't get beyond
32206 jan 20 0 330m 73m 7036 R 82 0.9 1:06.00 qemu-system-arm
32204 jan 20 0 330m 73m 7036 S 21 0.9 0:17.03 qemu-system-arm
We don't benefit significantly, though, when the guest is not fully
loading a host CPU.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Message-Id: <1439220437-23957-10-git-send-email-fred.konrad@greensocs.com>
[FK: Rebase, fix qemu_devices_reset deadlock, rm address_space_* mutex]
Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com>
[EGC: fixed iothread lock for cpu-exec IRQ handling]
Signed-off-by: Emilio G. Cota <cota@braap.org>
[AJB: -smp single-threaded fix, clean commit msg, BQL fixes]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
[PM: target-arm changes]
Acked-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'target/i386')
| -rw-r--r-- | target/i386/smm_helper.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/target/i386/smm_helper.c b/target/i386/smm_helper.c index 4dd6a2c544..f051a77c4a 100644 --- a/target/i386/smm_helper.c +++ b/target/i386/smm_helper.c @@ -18,6 +18,7 @@ */ #include "qemu/osdep.h" +#include "qemu/main-loop.h" #include "cpu.h" #include "exec/helper-proto.h" #include "exec/log.h" @@ -42,11 +43,14 @@ void helper_rsm(CPUX86State *env) #define SMM_REVISION_ID 0x00020000 #endif +/* Called with iothread lock taken */ void cpu_smm_update(X86CPU *cpu) { CPUX86State *env = &cpu->env; bool smm_enabled = (env->hflags & HF_SMM_MASK); + g_assert(qemu_mutex_iothread_locked()); + if (cpu->smram) { memory_region_set_enabled(cpu->smram, smm_enabled); } @@ -333,7 +337,10 @@ void helper_rsm(CPUX86State *env) } env->hflags2 &= ~HF2_SMM_INSIDE_NMI_MASK; env->hflags &= ~HF_SMM_MASK; + + qemu_mutex_lock_iothread(); cpu_smm_update(cpu); + qemu_mutex_unlock_iothread(); qemu_log_mask(CPU_LOG_INT, "SMM: after RSM\n"); log_cpu_state_mask(CPU_LOG_INT, CPU(cpu), CPU_DUMP_CCOP); |