diff mbox series

[v5,3/3] timer: support EAL functions on Windows

Message ID 20200507130531.624-4-fady@mellanox.com (mailing list archive)
State Superseded, archived
Delegated to: Thomas Monjalon
Headers
Series eal timer split and implementation for Windows |

Checks

Context Check Description
ci/checkpatch success coding style OK

Commit Message

Fady Bader May 7, 2020, 1:05 p.m. UTC 
  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      | 77 +++++++++++++++++++++++++++++++++
 lib/librte_eal/windows/include/rte_os.h |  2 +
 lib/librte_eal/windows/meson.build      |  1 +
 5 files changed, 87 insertions(+)
 create mode 100644 lib/librte_eal/windows/eal_timer.c

Comments

Dmitry Kozlyuk May 7, 2020, 8:54 p.m. UTC | #1 
On 2020-05-07 16:05 GMT+0300 Fady Bader wrote:
> Implemented the needed Windows eal timer functions.
[snip]
> +void
> +rte_delay_us_sleep(unsigned int us)
> +{
> +	LARGE_INTEGER start, end;
> +	LARGE_INTEGER freq;
> +
> +	QueryPerformanceCounter(&start);
> +	QueryPerformanceFrequency(&freq);
> +
> +	LARGE_INTEGER ticks;
> +	ticks.QuadPart = freq.QuadPart * us / US_PER_SEC;
> +
> +	QueryPerformanceCounter(&end);
> +	while ((end.QuadPart - start.QuadPart) < ticks.QuadPart) {
> +		rte_pause();
> +		QueryPerformanceCounter(&end);
> +	}
> +}

Your previous implementation was correct, this one is not. Per documentation,
rte_delay_us_sleep() should *sleep* in an OS-dependent way, like you did with
waitable timers previously, while rte_delay_us() does a busy loop like this.
Please restore this function from v4, the rest LGTM.

P.S. Fixed my email in Cc.
diff mbox series

Patch

diff --git a/lib/librte_eal/common/meson.build b/lib/librte_eal/common/meson.build
index 155da29b4..0ea995573 100644
--- a/lib/librte_eal/common/meson.build
+++ b/lib/librte_eal/common/meson.build
@@ -14,6 +14,7 @@  if is_windows
 		'eal_common_log.c',
 		'eal_common_options.c',
 		'eal_common_thread.c',
+		'eal_common_timer.c',
 		'rte_option.c',
 	)
 	subdir_done()
diff --git a/lib/librte_eal/windows/eal.c b/lib/librte_eal/windows/eal.c
index 831179799..4bc8fbfab 100644
--- a/lib/librte_eal/windows/eal.c
+++ b/lib/librte_eal/windows/eal.c
@@ -248,6 +248,12 @@  rte_eal_init(int argc, char **argv)
 	if (fctret < 0)
 		exit(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) {
diff --git a/lib/librte_eal/windows/eal_timer.c b/lib/librte_eal/windows/eal_timer.c
new file mode 100644
index 000000000..2d2929fb3
--- /dev/null
+++ b/lib/librte_eal/windows/eal_timer.c
@@ -0,0 +1,77 @@ 
+/* 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_pause.h>
+#include <rte_eal.h>
+#include <rte_errno.h>
+#include "eal_private.h"
+
+#define US_PER_SEC 1E6
+#define CYC_PER_10MHZ 1E7
+
+void
+rte_delay_us_sleep(unsigned int us)
+{
+	LARGE_INTEGER start, end;
+	LARGE_INTEGER freq;
+
+	QueryPerformanceCounter(&start);
+	QueryPerformanceFrequency(&freq);
+
+	LARGE_INTEGER ticks;
+	ticks.QuadPart = freq.QuadPart * us / US_PER_SEC;
+
+	QueryPerformanceCounter(&end);
+	while ((end.QuadPart - start.QuadPart) < ticks.QuadPart) {
+		rte_pause();
+		QueryPerformanceCounter(&end);
+	}
+}
+
+uint64_t
+get_tsc_freq(void)
+{
+	LARGE_INTEGER t_start, t_end, elapsed_us;
+	LARGE_INTEGER frequency;
+	uint64_t tsc_hz;
+	uint64_t end, start = rte_get_tsc_cycles();
+
+	QueryPerformanceFrequency(&frequency);
+	QueryPerformanceCounter(&t_start);
+
+	rte_delay_us_sleep(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);
+}
+
+
+int
+rte_eal_timer_init(void)
+{
+	set_tsc_freq();
+	return 0;
+}
+
+
diff --git a/lib/librte_eal/windows/include/rte_os.h b/lib/librte_eal/windows/include/rte_os.h
index 510e39e03..6410b9c2f 100644
--- a/lib/librte_eal/windows/include/rte_os.h
+++ b/lib/librte_eal/windows/include/rte_os.h
@@ -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 */
diff --git a/lib/librte_eal/windows/meson.build b/lib/librte_eal/windows/meson.build
index 09dd4ab2f..c796f289d 100644
--- a/lib/librte_eal/windows/meson.build
+++ b/lib/librte_eal/windows/meson.build
@@ -8,5 +8,6 @@  sources += files(
 	'eal_debug.c',
 	'eal_lcore.c',
 	'eal_thread.c',
+	'eal_timer.c',
 	'getopt.c',
 )