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| 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 /hw/ppc | |
| parent | 791158d93b27f22a17c2ada06621831d54f09a2c (diff) | |
| download | focaccia-qemu-8d04fb55dec381bc5105cb47f29d918e579e8cbd.tar.gz focaccia-qemu-8d04fb55dec381bc5105cb47f29d918e579e8cbd.zip | |
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 'hw/ppc')
| -rw-r--r-- | hw/ppc/ppc.c | 16 | ||||
| -rw-r--r-- | hw/ppc/spapr.c | 3 |
2 files changed, 18 insertions, 1 deletions
diff --git a/hw/ppc/ppc.c b/hw/ppc/ppc.c index d171e60b5c..5f93083d4a 100644 --- a/hw/ppc/ppc.c +++ b/hw/ppc/ppc.c @@ -62,7 +62,16 @@ void ppc_set_irq(PowerPCCPU *cpu, int n_IRQ, int level) { CPUState *cs = CPU(cpu); CPUPPCState *env = &cpu->env; - unsigned int old_pending = env->pending_interrupts; + unsigned int old_pending; + bool locked = false; + + /* We may already have the BQL if coming from the reset path */ + if (!qemu_mutex_iothread_locked()) { + locked = true; + qemu_mutex_lock_iothread(); + } + + old_pending = env->pending_interrupts; if (level) { env->pending_interrupts |= 1 << n_IRQ; @@ -80,9 +89,14 @@ void ppc_set_irq(PowerPCCPU *cpu, int n_IRQ, int level) #endif } + LOG_IRQ("%s: %p n_IRQ %d level %d => pending %08" PRIx32 "req %08x\n", __func__, env, n_IRQ, level, env->pending_interrupts, CPU(cpu)->interrupt_request); + + if (locked) { + qemu_mutex_unlock_iothread(); + } } /* PowerPC 6xx / 7xx internal IRQ controller */ diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c index e465d7ac98..b1e374f3f9 100644 --- a/hw/ppc/spapr.c +++ b/hw/ppc/spapr.c @@ -1010,6 +1010,9 @@ static void emulate_spapr_hypercall(PPCVirtualHypervisor *vhyp, { CPUPPCState *env = &cpu->env; + /* The TCG path should also be holding the BQL at this point */ + g_assert(qemu_mutex_iothread_locked()); + if (msr_pr) { hcall_dprintf("Hypercall made with MSR[PR]=1\n"); env->gpr[3] = H_PRIVILEGE; |