On Wed, Mar 09, 2022 at 11:58:01PM +0800, huang...@chinatelecom.cn wrote:
> From: Hyman Huang(黄勇) <huang...@chinatelecom.cn>
>
> Add dirty page rate limit test if kernel support dirty ring,
> create a standalone file to implement the test case.
Thanks for writting this test case.
>
> Signed-off-by: Hyman Huang(黄勇) <huang...@chinatelecom.cn>
> ---
> tests/qtest/dirtylimit-test.c | 288
> ++++++++++++++++++++++++++++++++++++++++++
> tests/qtest/meson.build | 2 +
> 2 files changed, 290 insertions(+)
> create mode 100644 tests/qtest/dirtylimit-test.c
>
> diff --git a/tests/qtest/dirtylimit-test.c b/tests/qtest/dirtylimit-test.c
> new file mode 100644
> index 0000000..07eac2c
> --- /dev/null
> +++ b/tests/qtest/dirtylimit-test.c
> @@ -0,0 +1,288 @@
> +/*
> + * QTest testcase for Dirty Page Rate Limit
> + *
> + * 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.
> + */
> +
> +#include "qemu/osdep.h"
> +#include "libqos/libqtest.h"
> +#include "qapi/qmp/qdict.h"
> +#include "qapi/qmp/qlist.h"
> +#include "qapi/qobject-input-visitor.h"
> +#include "qapi/qobject-output-visitor.h"
> +
> +#include "migration-helpers.h"
> +#include "tests/migration/i386/a-b-bootblock.h"
> +
> +/*
> + * Dirtylimit stop working if dirty page rate error
> + * value less than DIRTYLIMIT_TOLERANCE_RANGE
> + */
> +#define DIRTYLIMIT_TOLERANCE_RANGE 25 /* MB/s */
> +
> +static QDict *qmp_command(QTestState *who, const char *command, ...)
> +{
> + va_list ap;
> + QDict *resp, *ret;
> +
> + va_start(ap, command);
> + resp = qtest_vqmp(who, command, ap);
> + va_end(ap);
> +
> + g_assert(!qdict_haskey(resp, "error"));
> + g_assert(qdict_haskey(resp, "return"));
> +
> + ret = qdict_get_qdict(resp, "return");
> + qobject_ref(ret);
> + qobject_unref(resp);
> +
> + return ret;
> +}
> +
> +static void calc_dirty_rate(QTestState *who, uint64_t calc_time)
> +{
> + qobject_unref(qmp_command(who,
> + "{ 'execute': 'calc-dirty-rate',"
> + "'arguments': { "
> + "'calc-time': %ld,"
> + "'mode': 'dirty-ring' }}",
> + calc_time));
> +}
> +
> +static QDict *query_dirty_rate(QTestState *who)
> +{
> + return qmp_command(who, "{ 'execute': 'query-dirty-rate' }");
> +}
> +
> +static void dirtylimit_set_all(QTestState *who, uint64_t dirtyrate)
> +{
> + qobject_unref(qmp_command(who,
> + "{ 'execute': 'set-vcpu-dirty-limit',"
> + "'arguments': { "
> + "'dirty-rate': %ld } }",
> + dirtyrate));
> +}
> +
> +static void cancel_vcpu_dirty_limit(QTestState *who)
> +{
> + qobject_unref(qmp_command(who,
> + "{ 'execute': 'cancel-vcpu-dirty-limit' }"));
> +}
> +
> +static QDict *query_vcpu_dirty_limit(QTestState *who)
> +{
> + QDict *rsp;
> +
> + rsp = qtest_qmp(who, "{ 'execute': 'query-vcpu-dirty-limit' }");
> + g_assert(!qdict_haskey(rsp, "error"));
> + g_assert(qdict_haskey(rsp, "return"));
> +
> + return rsp;
> +}
> +
> +static int64_t get_dirty_rate(QTestState *who)
> +{
> + QDict *rsp_return;
> + gchar *status;
> + QList *rates;
> + const QListEntry *entry;
> + QDict *rate;
> + int64_t dirtyrate;
> +
> + rsp_return = query_dirty_rate(who);
> + g_assert(rsp_return);
> +
> + status = g_strdup(qdict_get_str(rsp_return, "status"));
> + g_assert(status);
> + g_assert_cmpstr(status, ==, "measured");
> +
> + rates = qdict_get_qlist(rsp_return, "vcpu-dirty-rate");
> + g_assert(rates && !qlist_empty(rates));
> +
> + entry = qlist_first(rates);
> + g_assert(entry);
> +
> + rate = qobject_to(QDict, qlist_entry_obj(entry));
> + g_assert(rate);
> +
> + dirtyrate = qdict_get_try_int(rate, "dirty-rate", -1);
> +
> + qobject_unref(rsp_return);
> + return dirtyrate;
> +}
> +
> +static int64_t get_limit_rate(QTestState *who)
> +{
> + QDict *rsp_return;
> + QList *rates;
> + const QListEntry *entry;
> + QDict *rate;
> + int64_t dirtyrate;
> +
> + rsp_return = query_vcpu_dirty_limit(who);
> + g_assert(rsp_return);
> +
> + rates = qdict_get_qlist(rsp_return, "return");
> + g_assert(rates && !qlist_empty(rates));
> +
> + entry = qlist_first(rates);
> + g_assert(entry);
> +
> + rate = qobject_to(QDict, qlist_entry_obj(entry));
> + g_assert(rate);
> +
> + dirtyrate = qdict_get_try_int(rate, "limit-rate", -1);
> +
> + qobject_unref(rsp_return);
> + return dirtyrate;
> +}
> +
> +static QTestState *start_vm(void)
> +{
> + QTestState *vm = NULL;
> + g_autofree gchar *cmd = NULL;
> + const char *arch = qtest_get_arch();
> + g_autofree char *bootpath = NULL;
> +
> + if (strcmp(arch, "i386") != 0 && strcmp(arch, "x86_64") != 0) {
> + return NULL;
> + }
Perhaps assert() on x86_64? Dirty ring support is checked earlier, so I
don't see how it'll fail... Very possible i386 will not ever support the
ring anyway.
> +
> + bootpath = g_strdup_printf("%s/bootsect", tmpfs);
> + assert(sizeof(x86_bootsect) == 512);
> + init_bootfile(bootpath, x86_bootsect, sizeof(x86_bootsect));
> +
> + cmd = g_strdup_printf("-accel kvm,dirty-ring-size=4096 -accel tcg "
> + "-name dirtylimit-test,debug-threads=on "
> + "-m 150M -smp 1 "
> + "-serial file:%s/vm_serial "
> + "-drive file=%s,format=raw ",
> + tmpfs, bootpath);
> +
> + vm = qtest_init(cmd);
> + return vm;
> +}
> +
> +static void stop_vm(QTestState *vm)
> +{
> + qtest_quit(vm);
> + cleanup("bootsect");
> + cleanup("vm_serial");
> +}
> +
> +static void test_vcpu_dirty_limit(void)
> +{
> + QTestState *vm;
> + int64_t origin_rate;
> + int64_t quota_rate;
> + int64_t rate ;
> + int max_try_count = 5;
> + int hit = 0;
> +
> + if (!(vm = start_vm())) {
> + return;
If you could change above into assert, then no "if" here.
> + }
> +
> + /* Wait for the first serial output from the vm*/
> + wait_for_serial("vm_serial");
> +
> + /* Do dirtyrate measurement with calc time equals 1s */
> + calc_dirty_rate(vm, 1);
> +
> + /* Sleep a little bit longer than calc time,
> + * and ensure dirtyrate measurement has been done
> + */
> + usleep(1200000);
Can we avoid using exact sleep numbers? We need to guarantee the test
doesn't fail even if the scheduler decides to do weird things..
How about loop until fetching a result, but with a timeout?
> +
> + /* Query original dirty page rate */
> + origin_rate = get_dirty_rate(vm);
> +
> + /* VM booted from bootsect should dirty memory */
> + assert(origin_rate != 0);
> +
> + /* Setup quota dirty page rate at one-third of origin */
> + quota_rate = origin_rate / 3;
> +
> + /* Set dirtylimit and wait a bit to check if it take effect */
> + dirtylimit_set_all(vm, quota_rate);
> + usleep(2000000);
> +
> + /* Check if set-vcpu-dirty-limit and query-vcpu-dirty-limit
> + * works literally */
> + g_assert_cmpint(quota_rate, ==, get_limit_rate(vm));
> +
> + /* Check if dirtylimit take effect realistically */
> + while (--max_try_count) {
> + calc_dirty_rate(vm, 1);
> + usleep(1200000);
Same here.
> + rate = get_dirty_rate(vm);
> +
> + /* Assume hitting if current rate is less
> + * than quota rate (within accepting error)
> + */
> + if (rate < (quota_rate + DIRTYLIMIT_TOLERANCE_RANGE)) {
> + hit = 1;
> + break;
> + }
> + }
> +
> + g_assert_cmpint(hit, ==, 1);
> +
> + hit = 0;
> + max_try_count = 5;
> +
> + /* Check if dirtylimit cancellation take effect */
> + cancel_vcpu_dirty_limit(vm);
> + while (--max_try_count) {
> + calc_dirty_rate(vm, 1);
> + usleep(1200000);
Same here.
> + rate = get_dirty_rate(vm);
> +
> + /* Assume dirtylimit be canceled if current rate is
> + * greater than quota rate (within accepting error)
> + */
> + if (rate > (quota_rate + DIRTYLIMIT_TOLERANCE_RANGE)) {
> + hit = 1;
> + break;
> + }
> + }
> +
> + g_assert_cmpint(hit, ==, 1);
> + stop_vm(vm);
> +}
Thanks,
--
Peter Xu
