Check how long it takes to get dirty log according to the number of
dirty pages, like:
get dirty log: 49 us for 1 dirty pages
get dirty log: 49 us for 2 dirty pages
get dirty log: 45 us for 4 dirty pages
get dirty log: 41 us for 8 dirty pages
get dirty log: 40 us for 16 dirty pages
get dirty log: 44 us for 32 dirty pages
get dirty log: 39 us for 64 dirty pages
get dirty log: 42 us for 128 dirty pages
get dirty log: 45 us for 256 dirty pages
get dirty log: 53 us for 512 dirty pages
get dirty log: 72 us for 1024 dirty pages
get dirty log: 99 us for 2048 dirty pages
get dirty log: 132 us for 4096 dirty pages
get dirty log: 224 us for 8192 dirty pages
get dirty log: 383 us for 16384 dirty pages
get dirty log: 725 us for 32768 dirty pages
get dirty log: 1412 us for 65536 dirty pages
get dirty log: 2746 us for 131072 dirty pages
get dirty log: 5455 us for 262144 dirty pages
Signed-off-by: Takuya Yoshikawa <takuya.yoshikawa@xxxxxxxxx>
---
api/dirty-log-perf.cc | 107 +++++++++++++++++++++++++++++++++++++++++++++++++
config-x86-common.mak | 3 +
2 files changed, 110 insertions(+), 0 deletions(-)
create mode 100644 api/dirty-log-perf.cc
diff --git a/api/dirty-log-perf.cc b/api/dirty-log-perf.cc
new file mode 100644
index 0000000..83413ce
--- /dev/null
+++ b/api/dirty-log-perf.cc
@@ -0,0 +1,107 @@
+#include "kvmxx.hh"
+#include "memmap.hh"
+#include "identity.hh"
+#include <boost/thread/thread.hpp>
+#include <stdlib.h>
+#include <stdio.h>
+#include <sys/time.h>
+
+namespace {
+
+const int page_size = 4096;
+const int nr_pages = 256 * 1024;
+
+void delay_loop(unsigned n)
+{
+ for (unsigned i = 0; i < n; ++i) {
+ asm volatile("pause");
+ }
+}
+
+void write_mem(volatile bool& running, volatile int& nr_dirty_pages,
+ void* logged_slot_virt)
+{
+ while (nr_dirty_pages >= 0) {
+ char* var = static_cast<char*>(logged_slot_virt);
+
+ while (!running) {
+ delay_loop(1000);
+ }
+ for (int i = 0; i < nr_dirty_pages; ++i) {
+ ++(*var);
+ var += page_size;
+ }
+ running = false;
+ }
+}
+
+void check_dirty_log(mem_slot& slot,
+ volatile bool& running,
+ volatile int& nr_dirty_pages)
+{
+ slot.set_dirty_logging(true);
+ slot.update_dirty_log();
+
+ for (int i = 1; i <= nr_pages; i *= 2) {
+ struct timeval start_time, end_time;
+ long time_usec;
+
+ nr_dirty_pages = i;
+ running = true;
+ // wait until the guest finishes writing
+ while (running) {
+ delay_loop(1000);
+ }
+
+ gettimeofday(&start_time, NULL);
+ slot.update_dirty_log();
+ gettimeofday(&end_time, NULL);
+
+ time_usec = 1000 * 1000 * (end_time.tv_sec - start_time.tv_sec);
+ time_usec += end_time.tv_usec - start_time.tv_usec;
+ printf("get dirty log: %6ld us for %10d dirty pages\n",
+ time_usec, nr_dirty_pages);
+ }
+
+ // stop the guest
+ nr_dirty_pages = -1;
+ running = true;
+ slot.set_dirty_logging(false);
+}
+
+}
+
+using boost::ref;
+using std::tr1::bind;
+
+int main(int ac, char **av)
+{
+ kvm::system sys;
+ kvm::vm vm(sys);
+ mem_map memmap(vm);
+
+ void* logged_slot_virt;
+ int memory_size = nr_pages * page_size;
+ if (posix_memalign(&logged_slot_virt, page_size, memory_size)) {
+ printf("dirty-log-perf: Could not allocate guest memory.\n");
+ exit(1);
+ }
+
+ identity::hole hole(logged_slot_virt, memory_size);
+ identity::vm ident_vm(vm, memmap, hole);
+ kvm::vcpu vcpu(vm, 0);
+ mem_slot logged_slot(memmap,
+ reinterpret_cast<uint64_t>(logged_slot_virt),
+ memory_size, logged_slot_virt);
+
+ bool running = false;
+ int nr_dirty_pages = 0;
+ boost::thread host_poll_thread(check_dirty_log, ref(logged_slot),
+ ref(running), ref(nr_dirty_pages));
+ identity::vcpu guest_write_thread(vcpu, bind(write_mem, ref(running),
+ ref(nr_dirty_pages),
+ logged_slot_virt));
+ vcpu.run();
+ host_poll_thread.join();
+ return 0;
+}
diff --git a/config-x86-common.mak b/config-x86-common.mak
index 1cbc7c6..a3e8ffa 100644
--- a/config-x86-common.mak
+++ b/config-x86-common.mak
@@ -39,6 +39,7 @@ tests-common = $(TEST_DIR)/vmexit.flat $(TEST_DIR)/tsc.flat \
ifdef API
tests-common += api/api-sample
tests-common += api/dirty-log
+tests-common += api/dirty-log-perf
endif
tests_and_config = $(TEST_DIR)/*.flat $(TEST_DIR)/unittests.cfg
@@ -102,3 +103,5 @@ api/libapi.a: api/kvmxx.o api/identity.o api/exception.o api/memmap.o
api/api-sample: api/api-sample.o api/libapi.a
api/dirty-log: api/dirty-log.o api/libapi.a
+
+api/dirty-log-perf: api/dirty-log-perf.o api/libapi.a
--
1.7.5.4
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