[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[PULL 07/34] softmmu/cpus: Check if the cpu work list is empty atomicall
From: |
Richard Henderson |
Subject: |
[PULL 07/34] softmmu/cpus: Check if the cpu work list is empty atomically |
Date: |
Fri, 11 Feb 2022 12:30:32 +1100 |
From: Idan Horowitz <idan.horowitz@gmail.com>
Instead of taking the lock of the cpu work list in order to check if it's
empty, we can just read the head pointer atomically. This decreases
cpu_work_list_empty's share from 5% to 1.3% in a profile of icount-enabled
aarch64-softmmu.
Signed-off-by: Idan Horowitz <idan.horowitz@gmail.com>
Message-Id: <20220114004358.299534-1-idan.horowitz@gmail.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
softmmu/cpus.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)
diff --git a/softmmu/cpus.c b/softmmu/cpus.c
index 23bca46b07..035395ae13 100644
--- a/softmmu/cpus.c
+++ b/softmmu/cpus.c
@@ -73,12 +73,7 @@ bool cpu_is_stopped(CPUState *cpu)
bool cpu_work_list_empty(CPUState *cpu)
{
- bool ret;
-
- qemu_mutex_lock(&cpu->work_mutex);
- ret = QSIMPLEQ_EMPTY(&cpu->work_list);
- qemu_mutex_unlock(&cpu->work_mutex);
- return ret;
+ return QSIMPLEQ_EMPTY_ATOMIC(&cpu->work_list);
}
bool cpu_thread_is_idle(CPUState *cpu)
--
2.25.1
- [PULL 00/34] tcg patch queue, Richard Henderson, 2022/02/10
- [PULL 01/34] common-user/host/sparc64: Fix safe_syscall_base, Richard Henderson, 2022/02/10
- [PULL 02/34] linux-user: Introduce host_signal_mask, Richard Henderson, 2022/02/10
- [PULL 03/34] linux-user: Introduce host_sigcontext, Richard Henderson, 2022/02/10
- [PULL 05/34] linux-user/include/host/sparc64: Fix host_sigcontext, Richard Henderson, 2022/02/10
- [PULL 04/34] linux-user: Move sparc/host-signal.h to sparc64/host-signal.h, Richard Henderson, 2022/02/10
- [PULL 11/34] tcg/aarch64: Support raising sigbus for user-only, Richard Henderson, 2022/02/10
- [PULL 07/34] softmmu/cpus: Check if the cpu work list is empty atomically,
Richard Henderson <=
- [PULL 08/34] replay: use CF_NOIRQ for special exception-replaying TB, Richard Henderson, 2022/02/10
- [PULL 06/34] accel/tcg: Optimize jump cache flush during tlb range flush, Richard Henderson, 2022/02/10
- [PULL 10/34] tcg/i386: Support raising sigbus for user-only, Richard Henderson, 2022/02/10
- [PULL 09/34] tcg/loongarch64: Fix fallout from recent MO_Q renaming, Richard Henderson, 2022/02/10
- [PULL 12/34] tcg/ppc: Support raising sigbus for user-only, Richard Henderson, 2022/02/10
- [PULL 15/34] tcg/tci: Support raising sigbus for user-only, Richard Henderson, 2022/02/10
- [PULL 14/34] tcg/s390x: Support raising sigbus for user-only, Richard Henderson, 2022/02/10
- [PULL 13/34] tcg/riscv: Support raising sigbus for user-only, Richard Henderson, 2022/02/10
- [PULL 17/34] tcg/arm: Drop support for armv4 and armv5 hosts, Richard Henderson, 2022/02/10
- [PULL 16/34] tcg/loongarch64: Support raising sigbus for user-only, Richard Henderson, 2022/02/10