[v4,2/2] timer: support EAL functions on Windows
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Commit Message
Implemented the needed Windows eal timer functions.
Signed-off-by: Fady Bader <fady@mellanox.com>
---
lib/librte_eal/common/meson.build | 1 +
lib/librte_eal/windows/eal.c | 6 +++
lib/librte_eal/windows/eal_timer.c | 96 +++++++++++++++++++++++++++++++++
lib/librte_eal/windows/include/rte_os.h | 2 +
lib/librte_eal/windows/meson.build | 1 +
5 files changed, 106 insertions(+)
create mode 100644 lib/librte_eal/windows/eal_timer.c
Comments
Getting extremely volatile results from get_tsc_hz(). Here's what I get from
10 successive calls:
freq=2660000000
freq=3220000000
freq=3740000000
freq=3870000000
freq=3830000000
freq=4060000000
freq=3370000000
freq=3820000000
freq=7370000000
freq=4970000000
Please see the last comment for the reason (and other comments inline).
On 2020-05-06 15:01 GMT+0300 Fady Bader wrote:
> Implemented the needed Windows eal timer functions.
>
> Signed-off-by: Fady Bader <fady@mellanox.com>
> ---
[snip]
> diff --git a/lib/librte_eal/windows/eal_timer.c b/lib/librte_eal/windows/eal_timer.c
> new file mode 100644
> index 000000000..108f66b54
> --- /dev/null
> +++ b/lib/librte_eal/windows/eal_timer.c
> @@ -0,0 +1,96 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright 2020 Mellanox Technologies, Ltd
> + */
> +#include <inttypes.h>
> +#include <time.h>
> +
> +#include <rte_windows.h>
> +#include <rte_common.h>
> +#include <rte_log.h>
> +#include <rte_cycles.h>
> +#include <rte_eal.h>
> +#include <rte_errno.h>
#include "eal_private.h", without it:
../../../lib/librte_eal/windows/eal_timer.c: In function ‘rte_eal_timer_init’:
../../../lib/librte_eal/windows/eal_timer.c:108:2: warning: implicit declaration of function ‘set_tsc_freq’; did you mean ‘get_tsc_freq’? [-Wimplicit-function-declaration]
108 | set_tsc_freq();
> +
> +#define US_PER_SEC 1E6
> +#define CYC_PER_10MHZ 1E7
> +
> +/* The frequency of the RDTSC timer resolution */
> +static uint64_t eal_tsc_resolution_hz;
> +
At top level:
../../../lib/librte_eal/windows/eal_timer.c:20:17: warning: ‘eal_tsc_resolution_hz’ defined but not used [-Wunused-variable]
20 | static uint64_t eal_tsc_resolution_hz;
Note: set_tsc_freq() already caches frequency you calculate here.
> + due_time.QuadPart = -(us * 10);
> + if (!SetWaitableTimer(timer, &due_time, 0, NULL, NULL, FALSE)) {
> + CloseHandle(timer);
> + RTE_LOG_WIN32_ERR("SetWaitableTimer()");
RTE_LOG_WIN32_ERR() uses GetLastError(), the value of which may be overridden
by a successful call to CloseHandle().
> + rte_errno = EINVAL;
> + return;
> + }
> + /* start wait for timer for us microseconds */
> + WaitForSingleObject(timer, INFINITE);
> + CloseHandle(timer);
> +}
> +
> +uint64_t
> +get_tsc_freq(void)
> +{
> + LARGE_INTEGER t_start, t_end, elapsed_us;
> + LARGE_INTEGER frequency;
> + uint64_t tsc_hz;
> +
> + if (QueryPerformanceFrequency(&frequency) == 0) {
> + RTE_LOG_WIN32_ERR("QueryPerformanceFrequency()");
> + return 0;
> + }
> +
> + if (QueryPerformanceCounter(&t_start) != 0) {
Per MSDN, QueryPerformanceFrequency() and QueryPerformanceCounter() always
succeed on all supported Windows versions.
> + uint64_t end, start = rte_get_tsc_cycles();
> +
> + rte_delay_us(US_PER_SEC / 10); /* 1/10 second */
Did you mean rte_delay_us_sleep()? rte_delay_us() assumes TSC frequency is
already available. With this fix, results become stable.
@@ -21,6 +21,7 @@ if is_windows
'eal_common_string_fns.c',
'eal_common_tailqs.c',
'eal_common_thread.c',
+ 'eal_common_timer.c',
'malloc_elem.c',
'malloc_heap.c',
'rte_malloc.c',
@@ -400,6 +400,12 @@ rte_eal_init(int argc, char **argv)
return -1;
}
+ if (rte_eal_timer_init() < 0) {
+ rte_eal_init_alert("Cannot init TSC timer");
+ rte_errno = EFAULT;
+ return -1;
+ }
+
eal_thread_init_master(rte_config.master_lcore);
RTE_LCORE_FOREACH_SLAVE(i) {
new file mode 100644
@@ -0,0 +1,96 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright 2020 Mellanox Technologies, Ltd
+ */
+#include <inttypes.h>
+#include <time.h>
+
+#include <rte_windows.h>
+#include <rte_common.h>
+#include <rte_log.h>
+#include <rte_cycles.h>
+#include <rte_eal.h>
+#include <rte_errno.h>
+
+#define US_PER_SEC 1E6
+#define CYC_PER_10MHZ 1E7
+
+/* The frequency of the RDTSC timer resolution */
+static uint64_t eal_tsc_resolution_hz;
+
+void
+rte_delay_us_sleep(unsigned int us)
+{
+ HANDLE timer;
+ LARGE_INTEGER due_time;
+
+ /* create waitable timer */
+ timer = CreateWaitableTimer(NULL, TRUE, NULL);
+ if (!timer) {
+ RTE_LOG_WIN32_ERR("CreateWaitableTimer()");
+ rte_errno = ENOMEM;
+ return;
+ }
+
+ /*
+ * due_time's uom is 100 ns, multiply by 10 to convert to microseconds
+ * set us microseconds time for timer
+ */
+ due_time.QuadPart = -(us * 10);
+ if (!SetWaitableTimer(timer, &due_time, 0, NULL, NULL, FALSE)) {
+ CloseHandle(timer);
+ RTE_LOG_WIN32_ERR("SetWaitableTimer()");
+ rte_errno = EINVAL;
+ return;
+ }
+ /* start wait for timer for us microseconds */
+ WaitForSingleObject(timer, INFINITE);
+ CloseHandle(timer);
+}
+
+uint64_t
+get_tsc_freq(void)
+{
+ LARGE_INTEGER t_start, t_end, elapsed_us;
+ LARGE_INTEGER frequency;
+ uint64_t tsc_hz;
+
+ if (QueryPerformanceFrequency(&frequency) == 0) {
+ RTE_LOG_WIN32_ERR("QueryPerformanceFrequency()");
+ return 0;
+ }
+
+ if (QueryPerformanceCounter(&t_start) != 0) {
+ uint64_t end, start = rte_get_tsc_cycles();
+
+ rte_delay_us(US_PER_SEC / 10); /* 1/10 second */
+
+ QueryPerformanceCounter(&t_end);
+ end = rte_get_tsc_cycles();
+
+ elapsed_us.QuadPart = t_end.QuadPart - t_start.QuadPart;
+
+ /*
+ * To guard against loss-of-precision, convert to microseconds
+ * *before* dividing by ticks-per-second.
+ */
+ elapsed_us.QuadPart *= US_PER_SEC;
+ elapsed_us.QuadPart /= frequency.QuadPart;
+
+ double secs = ((double)elapsed_us.QuadPart)/US_PER_SEC;
+ tsc_hz = (uint64_t)((end - start)/secs);
+ /* Round up to 10Mhz. 1E7 ~ 10Mhz */
+ return RTE_ALIGN_MUL_NEAR(tsc_hz, CYC_PER_10MHZ);
+ }
+
+ RTE_LOG_WIN32_ERR("QueryPerformanceCounter()");
+ return 0;
+}
+
+
+int
+rte_eal_timer_init(void)
+{
+ set_tsc_freq();
+ return 0;
+}
+
@@ -24,6 +24,8 @@ extern "C" {
#define PATH_MAX _MAX_PATH
#endif
+#define sleep(x) Sleep(1000 * (x))
+
#define strerror_r(a, b, c) strerror_s(b, c, a)
/* strdup is deprecated in Microsoft libc and _strdup is preferred */
@@ -12,6 +12,7 @@ sources += files(
'eal_memory.c',
'eal_mp.c',
'eal_thread.c',
+ 'eal_timer.c',
'getopt.c',
)