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From: "Philippe Mathieu-Daudé" <philmd@linaro.org>
To: qemu-devel@nongnu.org
Cc: "Peter Maydell" <peter.maydell@linaro.org>,
	"Yanan Wang" <wangyanan55@huawei.com>,
	"Eduardo Habkost" <eduardo@habkost.net>,
	"Harsh Prateek Bora" <harshpb@linux.ibm.com>,
	kvm@vger.kernel.org, "Zhao Liu" <zhao1.liu@intel.com>,
	"Daniel P. Berrangé" <berrange@redhat.com>,
	"Markus Armbruster" <armbru@redhat.com>,
	"Igor Mammedov" <imammedo@redhat.com>,
	"Marcel Apfelbaum" <marcel.apfelbaum@gmail.com>,
	"Peter Xu" <peterx@redhat.com>,
	"Philippe Mathieu-Daudé" <philmd@linaro.org>,
	"Paolo Bonzini" <pbonzini@redhat.com>,
	"Richard Henderson" <richard.henderson@linaro.org>
Subject: [RFC PATCH 1/9] accel/tcg: Simplify use of &first_cpu in rr_cpu_thread_fn()
Date: Tue, 28 Jan 2025 15:21:44 +0100	[thread overview]
Message-ID: <20250128142152.9889-2-philmd@linaro.org> (raw)
In-Reply-To: <20250128142152.9889-1-philmd@linaro.org>

Let vCPUs wait for themselves being ready first, then other ones.
This allows the first thread to starts without the global vcpu
queue (thus &first_cpu) being populated.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 accel/tcg/tcg-accel-ops-rr.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/accel/tcg/tcg-accel-ops-rr.c b/accel/tcg/tcg-accel-ops-rr.c
index 028b385af9a..5ad3d617bce 100644
--- a/accel/tcg/tcg-accel-ops-rr.c
+++ b/accel/tcg/tcg-accel-ops-rr.c
@@ -197,20 +197,21 @@ static void *rr_cpu_thread_fn(void *arg)
     qemu_guest_random_seed_thread_part2(cpu->random_seed);
 
     /* wait for initial kick-off after machine start */
-    while (first_cpu->stopped) {
-        qemu_cond_wait_bql(first_cpu->halt_cond);
+    while (cpu->stopped) {
+        CPUState *iter_cpu;
+
+        qemu_cond_wait_bql(cpu->halt_cond);
 
         /* process any pending work */
-        CPU_FOREACH(cpu) {
-            current_cpu = cpu;
-            qemu_wait_io_event_common(cpu);
+        CPU_FOREACH(iter_cpu) {
+            current_cpu = iter_cpu;
+            qemu_wait_io_event_common(iter_cpu);
         }
     }
 
+    g_assert(first_cpu);
     rr_start_kick_timer();
 
-    cpu = first_cpu;
-
     /* process any pending work */
     cpu->exit_request = 1;
 
-- 
2.47.1



  reply	other threads:[~2025-01-28 14:22 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-01-28 14:21 [RFC PATCH 0/9] accel: Only include qdev-realized vCPUs in global &cpus_queue Philippe Mathieu-Daudé
2025-01-28 14:21 ` Philippe Mathieu-Daudé [this message]
2025-01-28 19:44   ` [RFC PATCH 1/9] accel/tcg: Simplify use of &first_cpu in rr_cpu_thread_fn() Richard Henderson
2025-01-28 14:21 ` [RFC PATCH 2/9] accel/tcg: Invalidate TB jump cache with global vCPU queue locked Philippe Mathieu-Daudé
2025-01-28 20:05   ` Richard Henderson
2025-01-28 14:21 ` [RFC PATCH 3/9] cpus: Remove cpu from global queue after UNREALIZE completed Philippe Mathieu-Daudé
2025-01-28 20:08   ` Richard Henderson
2025-01-28 14:21 ` [RFC PATCH 4/9] hw/qdev: Introduce DeviceClass::[un]wire() handlers Philippe Mathieu-Daudé
2025-01-28 20:52   ` Richard Henderson
2025-02-04 13:39     ` Igor Mammedov
2025-01-28 14:21 ` [PATCH 5/9] cpus: Add DeviceClass::[un]wire() stubs Philippe Mathieu-Daudé
2025-01-28 20:53   ` Richard Henderson
2025-01-28 14:21 ` [PATCH 6/9] cpus: Call hotplug handlers in DeviceWire() Philippe Mathieu-Daudé
2025-01-28 20:53   ` Richard Henderson
2025-01-28 14:21 ` [RFC PATCH 7/9] cpus: Only expose REALIZED vCPUs to global &cpus_queue Philippe Mathieu-Daudé
2025-01-28 20:53   ` Richard Henderson
2025-01-28 20:55   ` Richard Henderson
2025-01-28 14:21 ` [PATCH 8/9] accel/kvm: Assert vCPU is created when calling kvm_dirty_ring_reap*() Philippe Mathieu-Daudé
2025-01-28 20:57   ` Richard Henderson
2025-01-28 14:21 ` [PATCH 9/9] accel/kvm: Remove unreachable assertion in kvm_dirty_ring_reap*() Philippe Mathieu-Daudé
2025-01-28 20:58   ` Richard Henderson
2025-02-07 15:45 ` [RFC PATCH 0/9] accel: Only include qdev-realized vCPUs in global &cpus_queue Igor Mammedov
2025-02-09 18:02   ` Philippe Mathieu-Daudé

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