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[2001:4830:134:3::11]) by mx.google.com with ESMTPS id e63si8492334qtd.131.2017.02.09.09.33.43 for (version=TLS1 cipher=AES128-SHA bits=128/128); Thu, 09 Feb 2017 09:33:43 -0800 (PST) Received-SPF: pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 2001:4830:134:3::11 as permitted sender) client-ip=2001:4830:134:3::11; Authentication-Results: mx.google.com; dkim=fail header.i=@linaro.org; spf=pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 2001:4830:134:3::11 as permitted sender) smtp.mailfrom=qemu-devel-bounces+patch=linaro.org@nongnu.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: from localhost ([::1]:39320 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cbsbF-0003Jc-4Z for patch@linaro.org; Thu, 09 Feb 2017 12:33:41 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56775) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cbsDR-0006I7-93 for qemu-devel@nongnu.org; Thu, 09 Feb 2017 12:09:10 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cbsDN-0002Q5-5W for qemu-devel@nongnu.org; Thu, 09 Feb 2017 12:09:05 -0500 Received: from mail-wm0-x234.google.com ([2a00:1450:400c:c09::234]:38515) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1cbsDM-0002Pt-TE for qemu-devel@nongnu.org; Thu, 09 Feb 2017 12:09:01 -0500 Received: by mail-wm0-x234.google.com with SMTP id r141so25974224wmg.1 for ; Thu, 09 Feb 2017 09:09:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=BKw89ocY4/0dJPSwMb0oYlIVbdRwj/OPCIR1v1Suqsk=; b=jk65fEkaUKh3EaNVcuJCC1WGLoDOGdpR7u3xHeqFBBlWeaf/LMvArSVN8Wv8O1OkTB b4cYTuBzONeR6BzQUVP1tlWRUI7bdwn1bFAkWibKjH3n4dUhLfBLLBLSfiztRrG/9+58 k93P2HPzsfDsZjvY/Y350n4lu4QaGrM6q4Jgs= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=BKw89ocY4/0dJPSwMb0oYlIVbdRwj/OPCIR1v1Suqsk=; b=O/iP72dy4brVAMzZN4DZ5LmHxa9HoXLhtzj1UIStpOyCj2fWk+XyuJZMxV4f/y2Pf9 ZmSwEAuzPUZQhrg7wRsDxSvjSSd+dpb1m64q/CneDC3YgPcswG1Th5Uxcszs4yY9TRSH o7Wful0xN9SL3R/PbnMBD60uD6HXOCpYzg6YNrxVMZipLvqHtxzEpOHxoKSVoRma7qU9 x7EKRUQ5wC9qJGZBjQW7s9KP6mIpqcCY6VS1vjvJ+RF9tZ6MM14XtJ+jnmBDESlH1yh8 uYv5Nwr7e8qk5dKIR0dum8a4gdqJGVMqKd3GSd3PfnT/rTf0XIdFYK/87ngxjs7/RIoh BEUg== X-Gm-Message-State: AMke39lSsd9EOGPmD5jrUmLoaDmRSqWooQxeZurZqGeY0bjcDor/JXQ5Qum4Y1rPm8TAkim+ X-Received: by 10.28.125.22 with SMTP id y22mr4000977wmc.112.1486660139865; Thu, 09 Feb 2017 09:08:59 -0800 (PST) Received: from zen.linaro.local ([81.128.185.34]) by smtp.gmail.com with ESMTPSA id 191sm9799307wmo.21.2017.02.09.09.08.54 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 09 Feb 2017 09:08:56 -0800 (PST) Received: from zen.linaroharston (localhost [127.0.0.1]) by zen.linaro.local (Postfix) with ESMTP id 46A293E2D49; Thu, 9 Feb 2017 17:09:05 +0000 (GMT) From: =?utf-8?q?Alex_Benn=C3=A9e?= To: peter.maydell@linaro.org, rth@twiddle.net Date: Thu, 9 Feb 2017 17:08:47 +0000 Message-Id: <20170209170904.5713-8-alex.bennee@linaro.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170209170904.5713-1-alex.bennee@linaro.org> References: <20170209170904.5713-1-alex.bennee@linaro.org> MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2a00:1450:400c:c09::234 Subject: [Qemu-devel] [PATCH v11 07/24] tcg: rename tcg_current_cpu to tcg_current_rr_cpu X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mttcg@listserver.greensocs.com, nikunj@linux.vnet.ibm.com, Peter Crosthwaite , jan.kiszka@siemens.com, mark.burton@greensocs.com, a.rigo@virtualopensystems.com, qemu-devel@nongnu.org, cota@braap.org, serge.fdrv@gmail.com, pbonzini@redhat.com, bobby.prani@gmail.com, =?utf-8?q?Alex_Benn=C3=A9e?= , bamvor.zhangjian@linaro.org, fred.konrad@greensocs.com Errors-To: qemu-devel-bounces+patch=linaro.org@nongnu.org Sender: "Qemu-devel" ..and make the definition local to cpus. In preparation for MTTCG the concept of a global tcg_current_cpu will no longer make sense. However we still need to keep track of it in the single-threaded case to be able to exit quickly when required. qemu_cpu_kick_no_halt() moves and becomes qemu_cpu_kick_rr_cpu() to emphasise its use-case. qemu_cpu_kick now kicks the relevant cpu as well as qemu_kick_rr_cpu() which will become a no-op in MTTCG. For the time being the setting of the global exit_request remains. Signed-off-by: Alex Bennée Reviewed-by: Richard Henderson Reviewed-by: Pranith Kumar --- v4: - keep global exit_request setting for now - fix merge conflicts v5: - merge conflicts with kick changes --- cpu-exec-common.c | 1 - cpu-exec.c | 3 --- cpus.c | 41 ++++++++++++++++++++++------------------- include/exec/exec-all.h | 1 - 4 files changed, 22 insertions(+), 24 deletions(-) -- 2.11.0 diff --git a/cpu-exec-common.c b/cpu-exec-common.c index 767d9c6f0c..e2bc053372 100644 --- a/cpu-exec-common.c +++ b/cpu-exec-common.c @@ -24,7 +24,6 @@ #include "exec/memory-internal.h" bool exit_request; -CPUState *tcg_current_cpu; /* exit the current TB, but without causing any exception to be raised */ void cpu_loop_exit_noexc(CPUState *cpu) diff --git a/cpu-exec.c b/cpu-exec.c index 97ff37eb73..b102af7f89 100644 --- a/cpu-exec.c +++ b/cpu-exec.c @@ -609,7 +609,6 @@ int cpu_exec(CPUState *cpu) return EXCP_HALTED; } - atomic_mb_set(&tcg_current_cpu, cpu); rcu_read_lock(); if (unlikely(atomic_mb_read(&exit_request))) { @@ -668,7 +667,5 @@ int cpu_exec(CPUState *cpu) /* fail safe : never use current_cpu outside cpu_exec() */ current_cpu = NULL; - /* Does not need atomic_mb_set because a spurious wakeup is okay. */ - atomic_set(&tcg_current_cpu, NULL); return ret; } diff --git a/cpus.c b/cpus.c index 6a15f9dc47..77bf06c7e4 100644 --- a/cpus.c +++ b/cpus.c @@ -780,8 +780,7 @@ void configure_icount(QemuOpts *opts, Error **errp) */ static QEMUTimer *tcg_kick_vcpu_timer; - -static void qemu_cpu_kick_no_halt(void); +static CPUState *tcg_current_rr_cpu; #define TCG_KICK_PERIOD (NANOSECONDS_PER_SECOND / 10) @@ -790,10 +789,23 @@ static inline int64_t qemu_tcg_next_kick(void) return qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + TCG_KICK_PERIOD; } +/* Kick the currently round-robin scheduled vCPU */ +static void qemu_cpu_kick_rr_cpu(void) +{ + CPUState *cpu; + atomic_mb_set(&exit_request, 1); + do { + cpu = atomic_mb_read(&tcg_current_rr_cpu); + if (cpu) { + cpu_exit(cpu); + } + } while (cpu != atomic_mb_read(&tcg_current_rr_cpu)); +} + static void kick_tcg_thread(void *opaque) { timer_mod(tcg_kick_vcpu_timer, qemu_tcg_next_kick()); - qemu_cpu_kick_no_halt(); + qemu_cpu_kick_rr_cpu(); } static void start_tcg_kick_timer(void) @@ -813,7 +825,6 @@ static void stop_tcg_kick_timer(void) } } - /***********************************************************/ void hw_error(const char *fmt, ...) { @@ -1324,6 +1335,7 @@ static void *qemu_tcg_cpu_thread_fn(void *arg) } for (; cpu != NULL && !exit_request; cpu = CPU_NEXT(cpu)) { + atomic_mb_set(&tcg_current_rr_cpu, cpu); qemu_clock_enable(QEMU_CLOCK_VIRTUAL, (cpu->singlestep_enabled & SSTEP_NOTIMER) == 0); @@ -1343,6 +1355,8 @@ static void *qemu_tcg_cpu_thread_fn(void *arg) } } /* for cpu.. */ + /* Does not need atomic_mb_set because a spurious wakeup is okay. */ + atomic_set(&tcg_current_rr_cpu, NULL); /* Pairs with smp_wmb in qemu_cpu_kick. */ atomic_mb_set(&exit_request, 0); @@ -1421,24 +1435,13 @@ static void qemu_cpu_kick_thread(CPUState *cpu) #endif } -static void qemu_cpu_kick_no_halt(void) -{ - CPUState *cpu; - /* Ensure whatever caused the exit has reached the CPU threads before - * writing exit_request. - */ - atomic_mb_set(&exit_request, 1); - cpu = atomic_mb_read(&tcg_current_cpu); - if (cpu) { - cpu_exit(cpu); - } -} - void qemu_cpu_kick(CPUState *cpu) { qemu_cond_broadcast(cpu->halt_cond); if (tcg_enabled()) { - qemu_cpu_kick_no_halt(); + cpu_exit(cpu); + /* Also ensure current RR cpu is kicked */ + qemu_cpu_kick_rr_cpu(); } else { if (hax_enabled()) { /* @@ -1486,7 +1489,7 @@ void qemu_mutex_lock_iothread(void) atomic_dec(&iothread_requesting_mutex); } else { if (qemu_mutex_trylock(&qemu_global_mutex)) { - qemu_cpu_kick_no_halt(); + qemu_cpu_kick_rr_cpu(); qemu_mutex_lock(&qemu_global_mutex); } atomic_dec(&iothread_requesting_mutex); diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h index bbc9478a50..3cbd359dd7 100644 --- a/include/exec/exec-all.h +++ b/include/exec/exec-all.h @@ -404,7 +404,6 @@ bool memory_region_is_unassigned(MemoryRegion *mr); extern int singlestep; /* cpu-exec.c, accessed with atomic_mb_read/atomic_mb_set */ -extern CPUState *tcg_current_cpu; extern bool exit_request; #endif