在 2022/2/8 16:18, Peter Xu 写道:
On Mon, Jan 24, 2022 at 10:10:37PM +0800, huang...@chinatelecom.cn wrote:
diff --git a/cpus-common.c b/cpus-common.c
index 6e73d3e..63159d6 100644
--- a/cpus-common.c
+++ b/cpus-common.c
@@ -73,6 +73,7 @@ static int cpu_get_free_index(void)
}
CPUTailQ cpus = QTAILQ_HEAD_INITIALIZER(cpus);
+unsigned int cpu_list_generation_id;
void cpu_list_add(CPUState *cpu)
{
@@ -84,6 +85,7 @@ void cpu_list_add(CPUState *cpu)
assert(!cpu_index_auto_assigned);
}
QTAILQ_INSERT_TAIL_RCU(&cpus, cpu, node);
+ cpu_list_generation_id++;
}
void cpu_list_remove(CPUState *cpu)
@@ -96,6 +98,7 @@ void cpu_list_remove(CPUState *cpu)
QTAILQ_REMOVE_RCU(&cpus, cpu, node);
cpu->cpu_index = UNASSIGNED_CPU_INDEX;
+ cpu_list_generation_id++;
}
Could you move the cpu list gen id changes into a separate patch?
Yes, of course
CPUState *qemu_get_cpu(int index)
diff --git a/include/sysemu/dirtyrate.h b/include/sysemu/dirtyrate.h
new file mode 100644
index 0000000..ea4785f
--- /dev/null
+++ b/include/sysemu/dirtyrate.h
@@ -0,0 +1,31 @@
+/*
+ * dirty page rate helper functions
+ *
+ * Copyright (c) 2022 CHINA TELECOM CO.,LTD.
+ *
+ * Authors:
+ * Hyman Huang(黄勇) <huang...@chinatelecom.cn>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef QEMU_DIRTYRATE_H
+#define QEMU_DIRTYRATE_H
+
+extern unsigned int cpu_list_generation_id;
How about exporting a function cpu_list_generation_id_get() from the cpu code,
rather than referencing it directly?
Ok, this will be done along with "cpu list gen id changes" in a separate
patch
+int64_t vcpu_calculate_dirtyrate(int64_t calc_time_ms,
+ int64_t init_time_ms,
+ VcpuStat *stat,
+ unsigned int flag,
+ bool one_shot)
+{
+ DirtyPageRecord *records;
+ int64_t duration;
+ int64_t dirtyrate;
+ int i = 0;
+ unsigned int gen_id;
+
+retry:
+ cpu_list_lock();
+ gen_id = cpu_list_generation_id;
+ records = vcpu_dirty_stat_alloc(stat);
+ vcpu_dirty_stat_collect(stat, records, true);
+
+ duration = dirty_stat_wait(calc_time_ms, init_time_ms);
+ cpu_list_unlock();
Should release the lock before sleep (dirty_stat_wait)?
Good point, since we have introduced the cpu_list_generation_id and make
sure the we can handle the plug/unplug scenario, we can make the cpu
plug/unplug as fast as it can. :)
+
+ global_dirty_log_sync(flag, one_shot);
+
+ cpu_list_lock();
+ if (gen_id != cpu_list_generation_id) {
+ g_free(records);
+ g_free(stat->rates);
+ cpu_list_unlock();
+ goto retry;
+ }
+ vcpu_dirty_stat_collect(stat, records, false);
+ cpu_list_unlock();
+
+ for (i = 0; i < stat->nvcpu; i++) {
+ dirtyrate = do_calculate_dirtyrate(records[i], duration);
+
+ stat->rates[i].id = i;
+ stat->rates[i].dirty_rate = dirtyrate;
+
+ trace_dirtyrate_do_calculate_vcpu(i, dirtyrate);
+ }
+
+ g_free(records);
+
+ return duration;
+}
Thanks,
--
Best regard
Hyman Huang(黄勇)
