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From: Robert Foley <robert.foley@linaro.org>
To: qemu-devel@nongnu.org
Cc: richard.henderson@linaro.org, "Emilio G. Cota" <cota@braap.org>,
	alex.bennee@linaro.org, robert.foley@linaro.org,
	peter.puhov@linaro.org
Subject: [PATCH v8 01/74] cpu: convert queued work to a QSIMPLEQ
Date: Thu, 26 Mar 2020 15:30:43 -0400
Message-ID: <20200326193156.4322-2-robert.foley@linaro.org> (raw)
In-Reply-To: <20200326193156.4322-1-robert.foley@linaro.org>

From: "Emilio G. Cota" <cota@braap.org>

Instead of open-coding it.

While at it, make sure that all accesses to the list are
performed while holding the list's lock.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Robert Foley <robert.foley@linaro.org>
---
 cpus-common.c         | 25 ++++++++-----------------
 cpus.c                | 14 ++++++++++++--
 hw/core/cpu.c         |  1 +
 include/hw/core/cpu.h |  6 +++---
 4 files changed, 24 insertions(+), 22 deletions(-)

diff --git a/cpus-common.c b/cpus-common.c
index eaf590cb38..3d659df464 100644
--- a/cpus-common.c
+++ b/cpus-common.c
@@ -99,7 +99,7 @@ void cpu_list_remove(CPUState *cpu)
 }
 
 struct qemu_work_item {
-    struct qemu_work_item *next;
+    QSIMPLEQ_ENTRY(qemu_work_item) node;
     run_on_cpu_func func;
     run_on_cpu_data data;
     bool free, exclusive, done;
@@ -108,13 +108,7 @@ struct qemu_work_item {
 static void queue_work_on_cpu(CPUState *cpu, struct qemu_work_item *wi)
 {
     qemu_mutex_lock(&cpu->work_mutex);
-    if (cpu->queued_work_first == NULL) {
-        cpu->queued_work_first = wi;
-    } else {
-        cpu->queued_work_last->next = wi;
-    }
-    cpu->queued_work_last = wi;
-    wi->next = NULL;
+    QSIMPLEQ_INSERT_TAIL(&cpu->work_list, wi, node);
     wi->done = false;
     qemu_mutex_unlock(&cpu->work_mutex);
 
@@ -310,17 +304,14 @@ void process_queued_cpu_work(CPUState *cpu)
 {
     struct qemu_work_item *wi;
 
-    if (cpu->queued_work_first == NULL) {
+    qemu_mutex_lock(&cpu->work_mutex);
+    if (QSIMPLEQ_EMPTY(&cpu->work_list)) {
+        qemu_mutex_unlock(&cpu->work_mutex);
         return;
     }
-
-    qemu_mutex_lock(&cpu->work_mutex);
-    while (cpu->queued_work_first != NULL) {
-        wi = cpu->queued_work_first;
-        cpu->queued_work_first = wi->next;
-        if (!cpu->queued_work_first) {
-            cpu->queued_work_last = NULL;
-        }
+    while (!QSIMPLEQ_EMPTY(&cpu->work_list)) {
+        wi = QSIMPLEQ_FIRST(&cpu->work_list);
+        QSIMPLEQ_REMOVE_HEAD(&cpu->work_list, node);
         qemu_mutex_unlock(&cpu->work_mutex);
         if (wi->exclusive) {
             /* Running work items outside the BQL avoids the following deadlock:
diff --git a/cpus.c b/cpus.c
index ef441bdf62..151abbc04c 100644
--- a/cpus.c
+++ b/cpus.c
@@ -96,9 +96,19 @@ bool cpu_is_stopped(CPUState *cpu)
     return cpu->stopped || !runstate_is_running();
 }
 
+static inline bool cpu_work_list_empty(CPUState *cpu)
+{
+    bool ret;
+
+    qemu_mutex_lock(&cpu->work_mutex);
+    ret = QSIMPLEQ_EMPTY(&cpu->work_list);
+    qemu_mutex_unlock(&cpu->work_mutex);
+    return ret;
+}
+
 static bool cpu_thread_is_idle(CPUState *cpu)
 {
-    if (cpu->stop || cpu->queued_work_first) {
+    if (cpu->stop || !cpu_work_list_empty(cpu)) {
         return false;
     }
     if (cpu_is_stopped(cpu)) {
@@ -1490,7 +1500,7 @@ static void *qemu_tcg_rr_cpu_thread_fn(void *arg)
             cpu = first_cpu;
         }
 
-        while (cpu && !cpu->queued_work_first && !cpu->exit_request) {
+        while (cpu && cpu_work_list_empty(cpu) && !cpu->exit_request) {
 
             atomic_mb_set(&tcg_current_rr_cpu, cpu);
             current_cpu = cpu;
diff --git a/hw/core/cpu.c b/hw/core/cpu.c
index 786a1bec8a..2fc6aa2159 100644
--- a/hw/core/cpu.c
+++ b/hw/core/cpu.c
@@ -368,6 +368,7 @@ static void cpu_common_initfn(Object *obj)
     cpu->nr_threads = 1;
 
     qemu_mutex_init(&cpu->work_mutex);
+    QSIMPLEQ_INIT(&cpu->work_list);
     QTAILQ_INIT(&cpu->breakpoints);
     QTAILQ_INIT(&cpu->watchpoints);
 
diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
index 5bf94d28cf..398b65159e 100644
--- a/include/hw/core/cpu.h
+++ b/include/hw/core/cpu.h
@@ -331,8 +331,8 @@ struct qemu_work_item;
  * @opaque: User data.
  * @mem_io_pc: Host Program Counter at which the memory was accessed.
  * @kvm_fd: vCPU file descriptor for KVM.
- * @work_mutex: Lock to prevent multiple access to queued_work_*.
- * @queued_work_first: First asynchronous work pending.
+ * @work_mutex: Lock to prevent multiple access to @work_list.
+ * @work_list: List of pending asynchronous work.
  * @trace_dstate_delayed: Delayed changes to trace_dstate (includes all changes
  *                        to @trace_dstate).
  * @trace_dstate: Dynamic tracing state of events for this vCPU (bitmask).
@@ -376,7 +376,7 @@ struct CPUState {
     sigjmp_buf jmp_env;
 
     QemuMutex work_mutex;
-    struct qemu_work_item *queued_work_first, *queued_work_last;
+    QSIMPLEQ_HEAD(, qemu_work_item) work_list;
 
     CPUAddressSpace *cpu_ases;
     int num_ases;
-- 
2.17.1



  reply index

Thread overview: 100+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-26 19:30 [PATCH v8 00/74] per-CPU locks Robert Foley
2020-03-26 19:30 ` Robert Foley [this message]
2020-03-26 19:30 ` [PATCH v8 02/74] cpu: rename cpu->work_mutex to cpu->lock Robert Foley
2020-05-11 14:48   ` Alex Bennée
2020-05-11 16:33     ` Robert Foley
2020-03-26 19:30 ` [PATCH v8 03/74] cpu: introduce cpu_mutex_lock/unlock Robert Foley
2020-05-11 10:24   ` Alex Bennée
2020-05-11 16:09     ` Robert Foley
2020-03-26 19:30 ` [PATCH v8 04/74] cpu: make qemu_work_cond per-cpu Robert Foley
2020-03-26 19:30 ` [PATCH v8 05/74] cpu: move run_on_cpu to cpus-common Robert Foley
2020-03-26 19:30 ` [PATCH v8 06/74] cpu: introduce process_queued_cpu_work_locked Robert Foley
2020-03-26 19:30 ` [PATCH v8 07/74] cpu: make per-CPU locks an alias of the BQL in TCG rr mode Robert Foley
2020-03-26 19:30 ` [PATCH v8 08/74] tcg-runtime: define helper_cpu_halted_set Robert Foley
2020-03-26 19:30 ` [PATCH v8 09/74] ppc: convert to helper_cpu_halted_set Robert Foley
2020-03-26 19:30 ` [PATCH v8 10/74] cris: " Robert Foley
2020-03-26 19:30 ` [PATCH v8 11/74] hppa: " Robert Foley
2020-03-26 19:30 ` [PATCH v8 12/74] m68k: " Robert Foley
2020-03-26 19:30 ` [PATCH v8 13/74] alpha: " Robert Foley
2020-03-26 19:30 ` [PATCH v8 14/74] microblaze: " Robert Foley
2020-03-26 19:30 ` [PATCH v8 15/74] cpu: define cpu_halted helpers Robert Foley
2020-03-26 19:30 ` [PATCH v8 16/74] tcg-runtime: convert to cpu_halted_set Robert Foley
2020-03-26 19:30 ` [PATCH v8 17/74] hw/semihosting: " Robert Foley
2020-05-11 10:25   ` Alex Bennée
2020-03-26 19:31 ` [PATCH v8 18/74] arm: convert to cpu_halted Robert Foley
2020-03-26 19:31 ` [PATCH v8 19/74] ppc: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 20/74] sh4: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 21/74] i386: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 22/74] lm32: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 23/74] m68k: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 24/74] mips: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 25/74] riscv: " Robert Foley
2020-05-11 10:40   ` Alex Bennée
2020-05-11 16:13     ` Robert Foley
2020-03-26 19:31 ` [PATCH v8 26/74] s390x: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 27/74] sparc: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 28/74] xtensa: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 29/74] gdbstub: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 30/74] openrisc: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 31/74] cpu-exec: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 32/74] cpu: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 33/74] cpu: define cpu_interrupt_request helpers Robert Foley
2020-03-26 19:31 ` [PATCH v8 34/74] ppc: use cpu_reset_interrupt Robert Foley
2020-03-26 19:31 ` [PATCH v8 35/74] exec: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 36/74] i386: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 37/74] s390x: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 38/74] openrisc: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 39/74] arm: convert to cpu_interrupt_request Robert Foley
2020-03-26 19:31 ` [PATCH v8 40/74] i386: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 41/74] i386/kvm: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 42/74] i386/hax-all: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 43/74] i386/whpx-all: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 44/74] i386/hvf: convert to cpu_request_interrupt Robert Foley
2020-03-26 19:31 ` [PATCH v8 45/74] ppc: convert to cpu_interrupt_request Robert Foley
2020-03-26 19:31 ` [PATCH v8 46/74] sh4: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 47/74] cris: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 48/74] hppa: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 49/74] lm32: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 50/74] m68k: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 51/74] mips: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 52/74] nios: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 53/74] s390x: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 54/74] alpha: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 55/74] moxie: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 56/74] sparc: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 57/74] openrisc: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 58/74] unicore32: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 59/74] microblaze: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 60/74] accel/tcg: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 61/74] cpu: convert to interrupt_request Robert Foley
2020-03-26 19:31 ` [PATCH v8 62/74] cpu: call .cpu_has_work with the CPU lock held Robert Foley
2020-03-26 19:31 ` [PATCH v8 63/74] cpu: introduce cpu_has_work_with_iothread_lock Robert Foley
2020-03-26 19:31 ` [PATCH v8 64/74] ppc: convert to cpu_has_work_with_iothread_lock Robert Foley
2020-03-26 19:31 ` [PATCH v8 65/74] mips: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 66/74] s390x: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 67/74] riscv: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 68/74] sparc: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 69/74] xtensa: " Robert Foley
2020-03-26 19:31 ` [PATCH v8 70/74] cpu: rename all_cpu_threads_idle to qemu_tcg_rr_all_cpu_threads_idle Robert Foley
2020-03-26 19:31 ` [PATCH v8 71/74] cpu: protect CPU state with cpu->lock instead of the BQL Robert Foley
2020-03-26 19:31 ` [PATCH v8 72/74] cpus-common: release BQL earlier in run_on_cpu Robert Foley
2020-03-26 19:31 ` [PATCH v8 73/74] cpu: add async_run_on_cpu_no_bql Robert Foley
2020-03-26 19:31 ` [PATCH v8 74/74] cputlb: queue async flush jobs without the BQL Robert Foley
2020-05-12 16:27   ` Alex Bennée
2020-05-12 19:26     ` Robert Foley
2020-05-18 13:46       ` Robert Foley
2020-05-20  4:46         ` Emilio G. Cota
2020-05-20 15:01           ` Robert Foley
2020-05-21 14:17             ` Robert Foley
2020-05-12 18:38   ` Alex Bennée
2020-03-26 22:58 ` [PATCH v8 00/74] per-CPU locks Aleksandar Markovic
2020-03-27  9:39   ` Alex Bennée
2020-03-27  9:50     ` Aleksandar Markovic
2020-03-27 10:24       ` Aleksandar Markovic
2020-03-27 17:21         ` Robert Foley
2020-03-27  5:14 ` Emilio G. Cota
2020-03-27 10:59   ` Philippe Mathieu-Daudé
2020-03-30  8:57     ` Stefan Hajnoczi
2020-03-27 18:23   ` Alex Bennée
2020-03-27 18:30   ` Robert Foley
2020-05-12 16:29 ` Alex Bennée

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