diff options
| author | Sergey Fedorov <serge.fdrv@gmail.com> | 2016-07-15 20:58:50 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2016-09-13 19:08:43 +0200 |
| commit | 74d356dd48b64eaa2a6104ac1493ca64cb31fa16 (patch) | |
| tree | e04c2c06eae87993908e06048af9e078d533985b /cpu-exec.c | |
| parent | 518615c6503ad78d3bb67ddf1cd848c4a41de02e (diff) | |
tcg: Avoid bouncing tb_lock between tb_gen_code() and tb_add_jump()
Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20160715175852.30749-11-sergey.fedorov@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'cpu-exec.c')
| -rw-r--r-- | cpu-exec.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/cpu-exec.c b/cpu-exec.c index 7ca2b71a89..bd9fa5a538 100644 --- a/cpu-exec.c +++ b/cpu-exec.c @@ -282,7 +282,8 @@ static TranslationBlock *tb_find_physical(CPUState *cpu, static TranslationBlock *tb_find_slow(CPUState *cpu, target_ulong pc, target_ulong cs_base, - uint32_t flags) + uint32_t flags, + bool *have_tb_lock) { TranslationBlock *tb; @@ -295,6 +296,7 @@ static TranslationBlock *tb_find_slow(CPUState *cpu, */ mmap_lock(); tb_lock(); + *have_tb_lock = true; /* There's a chance that our desired tb has been translated while * taking the locks so we check again inside the lock. @@ -305,7 +307,6 @@ static TranslationBlock *tb_find_slow(CPUState *cpu, tb = tb_gen_code(cpu, pc, cs_base, flags, 0); } - tb_unlock(); mmap_unlock(); } @@ -322,6 +323,7 @@ static inline TranslationBlock *tb_find_fast(CPUState *cpu, TranslationBlock *tb; target_ulong cs_base, pc; uint32_t flags; + bool have_tb_lock = false; /* we record a subset of the CPU state. It will always be the same before a given translated block @@ -330,7 +332,7 @@ static inline TranslationBlock *tb_find_fast(CPUState *cpu, tb = atomic_rcu_read(&cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)]); if (unlikely(!tb || tb->pc != pc || tb->cs_base != cs_base || tb->flags != flags)) { - tb = tb_find_slow(cpu, pc, cs_base, flags); + tb = tb_find_slow(cpu, pc, cs_base, flags, &have_tb_lock); } #ifndef CONFIG_USER_ONLY /* We don't take care of direct jumps when address mapping changes in @@ -343,13 +345,18 @@ static inline TranslationBlock *tb_find_fast(CPUState *cpu, #endif /* See if we can patch the calling TB. */ if (last_tb && !qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)) { - tb_lock(); + if (!have_tb_lock) { + tb_lock(); + have_tb_lock = true; + } /* Check if translation buffer has been flushed */ if (cpu->tb_flushed) { cpu->tb_flushed = false; } else if (!tb->invalid) { tb_add_jump(last_tb, tb_exit, tb); } + } + if (have_tb_lock) { tb_unlock(); } return tb; |