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[97.113.7.119]) by smtp.gmail.com with ESMTPSA id d76sm15940571pfd.185.2019.10.13.15.26.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 13 Oct 2019 15:26:15 -0700 (PDT) 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=mbGjA7d6AQiFvZB5+xEjn3eOcLNF0/a+vXYuP56z9BY=; b=nZP+XcmwTKiIjP+VQdUQS35Akek47LhX0vjgUdvW9MBW8veUyAwEYWWyEtVBfTpTVz KYtFL/+amHtfr0PHG0WD12tF4E9ojPviuGwNGeBJQlJDQZkdNAFXGHXUhEXjzP9mt4lw 1nEtGGcVM7w4s6gzXNr46b+pSFmNueNRB9evbUTXb4jiltB2Ak3jbER4aR1GZqQO3Wzf ir3KVN4o1hBC7miFEC6B5hQ8apPEaW9V5CSAn39J5Uqv8de6PAS9XTpLp4hvWRAK7T5z uPMe4g494P5q6CVfxcrSZ4EK2lnZUJ8XMTRYnRV9trvoFQ+ba+/M0S08H3JrPct5ZW0C PjCg== 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=mbGjA7d6AQiFvZB5+xEjn3eOcLNF0/a+vXYuP56z9BY=; b=Ppa2EMDuNe0t6xkAcSgduBUmp6bjtj7w/DWhtN6iFr8CdhvJF4UBuT2SZKlsVQt2no m+A90i2rDD1dc1+v7jk5iTtMJEIbIHjh03Okooho92JYEHsstQPDGH4OS0DW7/on0Owa rK8eb+gU79zvV39jXiUr8aw1hQwCNZS/bGKVr64mYjbp0zcNkpZH2iz/VX99qiVpkEwM ystlC4lGjxRk7Ww3S8aFrpG+L625gBePKA5H4ATsMp2TL/uX3ftuRix/+tLRTA+qNukY 040SR8bMRDzVaHoeownntIKmBRAtEgv3tBGo5EPEo9Q2RqpDVudakUKCZonqLmk/dPVF z8bw== X-Gm-Message-State: APjAAAWJ6zLmQCeqV/rhSiNUgNS97MEJejlzIpe4O1Vs95tN6oPC2VZb lSWq64PYQQWrR7r7k/LP/+m8hFRRY/4= X-Google-Smtp-Source: APXvYqz3pFKflABq/EceH36FtATsW8NW30Ah8592YNPKBPXxx9yWu56q8xeeDM7Uz60qyEKwl9JbTg== X-Received: by 2002:aa7:9157:: with SMTP id 23mr30094311pfi.61.1571005576666; Sun, 13 Oct 2019 15:26:16 -0700 (PDT) From: Richard Henderson To: qemu-devel@nongnu.org Subject: [PULL 23/23] cpus: kick all vCPUs when running thread=single Date: Sun, 13 Oct 2019 15:25:44 -0700 Message-Id: <20191013222544.3679-24-richard.henderson@linaro.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20191013222544.3679-1-richard.henderson@linaro.org> References: <20191013222544.3679-1-richard.henderson@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2607:f8b0:4864:20::543 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: peter.maydell@linaro.org, =?UTF-8?q?Alex=20Benn=C3=A9e?= Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: pass (identity @linaro.org) From: Alex Benn=C3=A9e qemu_cpu_kick is used for a number of reasons including to indicate there is work to be done. However when thread=3Dsingle the old qemu_cpu_kick_rr_cpu only advanced the vCPU to the next executing one which can lead to a hang in the case that: a) the kick is from outside the vCPUs (e.g. iothread) b) the timers are paused (i.e. iothread calling run_on_cpu) To avoid this lets split qemu_cpu_kick_rr into two functions. One for the timer which continues to advance to the next timeslice and another for all other kicks. Message-Id: <20191001160426.26644-1-alex.bennee@linaro.org> Reviewed-by: Paolo Bonzini Reviewed-by: Richard Henderson Signed-off-by: Alex Benn=C3=A9e Signed-off-by: Richard Henderson --- cpus.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/cpus.c b/cpus.c index d2c61ff155..bee7209134 100644 --- a/cpus.c +++ b/cpus.c @@ -949,8 +949,8 @@ static inline int64_t qemu_tcg_next_kick(void) return qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + TCG_KICK_PERIOD; } =20 -/* Kick the currently round-robin scheduled vCPU */ -static void qemu_cpu_kick_rr_cpu(void) +/* Kick the currently round-robin scheduled vCPU to next */ +static void qemu_cpu_kick_rr_next_cpu(void) { CPUState *cpu; do { @@ -961,6 +961,16 @@ static void qemu_cpu_kick_rr_cpu(void) } while (cpu !=3D atomic_mb_read(&tcg_current_rr_cpu)); } =20 +/* Kick all RR vCPUs */ +static void qemu_cpu_kick_rr_cpus(void) +{ + CPUState *cpu; + + CPU_FOREACH(cpu) { + cpu_exit(cpu); + }; +} + static void do_nothing(CPUState *cpu, run_on_cpu_data unused) { } @@ -993,7 +1003,7 @@ void qemu_timer_notify_cb(void *opaque, QEMUClockType = type) static void kick_tcg_thread(void *opaque) { timer_mod(tcg_kick_vcpu_timer, qemu_tcg_next_kick()); - qemu_cpu_kick_rr_cpu(); + qemu_cpu_kick_rr_next_cpu(); } =20 static void start_tcg_kick_timer(void) @@ -1828,9 +1838,11 @@ void qemu_cpu_kick(CPUState *cpu) { qemu_cond_broadcast(cpu->halt_cond); if (tcg_enabled()) { - cpu_exit(cpu); - /* NOP unless doing single-thread RR */ - qemu_cpu_kick_rr_cpu(); + if (qemu_tcg_mttcg_enabled()) { + cpu_exit(cpu); + } else { + qemu_cpu_kick_rr_cpus(); + } } else { if (hax_enabled()) { /* --=20 2.17.1