From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58998) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cEMoF-0003Hh-GQ for qemu-devel@nongnu.org; Tue, 06 Dec 2016 15:57:56 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cEMoC-0006R5-Cp for qemu-devel@nongnu.org; Tue, 06 Dec 2016 15:57:55 -0500 Received: from mail-yw0-f193.google.com ([209.85.161.193]:35317) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1cEMoC-0006Ns-8u for qemu-devel@nongnu.org; Tue, 06 Dec 2016 15:57:52 -0500 Received: by mail-yw0-f193.google.com with SMTP id b66so29935695ywh.2 for ; Tue, 06 Dec 2016 12:57:30 -0800 (PST) From: Pranith Kumar Date: Tue, 6 Dec 2016 15:56:25 -0500 Message-Id: <20161206205627.8443-2-bobby.prani@gmail.com> In-Reply-To: <20161206205627.8443-1-bobby.prani@gmail.com> References: <20161206205627.8443-1-bobby.prani@gmail.com> Subject: [Qemu-devel] [RFC PATCH 1/3] tcg: Release tb_lock in the order acquired List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: alex.bennee@linaro.org Cc: qemu-devel@nongnu.org, rth@twiddle.net, mst@redhat.com, cota@braap.org We acquire mmap lock and tb lock in one order and release them in a different order. This does not need to be that way. This patch was inspired by a previous patch by Emilio G. Cota (https://lists.gnu.org/archive/html/qemu-devel/2016-08/msg03785.html). Signed-off-by: Pranith Kumar --- cpu-exec.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) diff --git a/cpu-exec.c b/cpu-exec.c index aa8318d864..f4a00f5047 100644 --- a/cpu-exec.c +++ b/cpu-exec.c @@ -318,7 +318,6 @@ static inline TranslationBlock *tb_find(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 @@ -336,7 +335,6 @@ static inline TranslationBlock *tb_find(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. @@ -347,6 +345,7 @@ static inline TranslationBlock *tb_find(CPUState *cpu, tb = tb_gen_code(cpu, pc, cs_base, flags, 0); } + tb_unlock(); mmap_unlock(); } @@ -364,17 +363,12 @@ static inline TranslationBlock *tb_find(CPUState *cpu, #endif /* See if we can patch the calling TB. */ if (last_tb && !qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)) { - if (!have_tb_lock) { - tb_lock(); - have_tb_lock = true; - } if (!tb->invalid) { + tb_lock(); tb_add_jump(last_tb, tb_exit, tb); + tb_unlock(); } } - if (have_tb_lock) { - tb_unlock(); - } return tb; } -- 2.11.0