[dpdk-dev] [PATCH v2 0/2] eal timer split and implementation for Windows

[dpdk-dev] [PATCH v2 0/2] eal timer split and implementation for Windows

[Fady Bader]

This patchset splits OS dependent EAL timer functions and implements them for windows.

v2:
    * fixing styles and correctness errors

Depends-on: series-9374 ("Windows basic memory management")

Fady Bader (2):
  timer: move from common to Unix directory
  timer: support EAL functions on Windows

 lib/librte_eal/common/eal_common_timer.c | 22 -----------
 lib/librte_eal/common/meson.build        |  1 +
 lib/librte_eal/unix/eal_timer.c          | 29 ++++++++++++++
 lib/librte_eal/unix/meson.build          |  1 +
 lib/librte_eal/windows/eal.c             |  6 +++
 lib/librte_eal/windows/eal_timer.c       | 68 ++++++++++++++++++++++++++++++++
 lib/librte_eal/windows/include/rte_os.h  |  2 +
 lib/librte_eal/windows/meson.build       |  1 +
 8 files changed, 108 insertions(+), 22 deletions(-)
 create mode 100644 lib/librte_eal/unix/eal_timer.c
 create mode 100644 lib/librte_eal/windows/eal_timer.c

-- 
2.16.1.windows.4

[dpdk-dev] [PATCH v2 1/2] timer: move from common to Unix directory

[Fady Bader]

Eal common timer doesn't compile under Windows.

Compilation log:
error LNK2019:
unresolved external symbol nanosleep referenced in function
rte_delay_us_sleep
error LNK2019:
unresolved external symbol get_tsc_freq referenced in function set_tsc_freq
error LNK2019:
unresolved external symbol sleep referenced in function set_tsc_freq

The reason was that some functions called POSIX functions.
The solution was to move POSIX dependent functions from common to Unix.

Signed-off-by: Fady Bader <fady@mellanox.com>
---
 lib/librte_eal/common/eal_common_timer.c | 22 ----------------------
 lib/librte_eal/unix/eal_timer.c          | 29 +++++++++++++++++++++++++++++
 lib/librte_eal/unix/meson.build          |  1 +
 3 files changed, 30 insertions(+), 22 deletions(-)
 create mode 100644 lib/librte_eal/unix/eal_timer.c

diff --git a/lib/librte_eal/common/eal_common_timer.c b/lib/librte_eal/common/eal_common_timer.c
index fa9ee1b22..71e0bd035 100644
--- a/lib/librte_eal/common/eal_common_timer.c
+++ b/lib/librte_eal/common/eal_common_timer.c
@@ -35,28 +35,6 @@ rte_delay_us_block(unsigned int us)
 		rte_pause();
 }
 
-void
-rte_delay_us_sleep(unsigned int us)
-{
-	struct timespec wait[2];
-	int ind = 0;
-
-	wait[0].tv_sec = 0;
-	if (us >= US_PER_S) {
-		wait[0].tv_sec = us / US_PER_S;
-		us -= wait[0].tv_sec * US_PER_S;
-	}
-	wait[0].tv_nsec = 1000 * us;
-
-	while (nanosleep(&wait[ind], &wait[1 - ind]) && errno == EINTR) {
-		/*
-		 * Sleep was interrupted. Flip the index, so the 'remainder'
-		 * will become the 'request' for a next call.
-		 */
-		ind = 1 - ind;
-	}
-}
-
 uint64_t
 rte_get_tsc_hz(void)
 {
diff --git a/lib/librte_eal/unix/eal_timer.c b/lib/librte_eal/unix/eal_timer.c
new file mode 100644
index 000000000..36189c346
--- /dev/null
+++ b/lib/librte_eal/unix/eal_timer.c
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright 2020 Mellanox Technologies, Ltd
+ */
+#include <time.h>
+
+#include <rte_cycles.h>
+
+void
+rte_delay_us_sleep(unsigned int us)
+{
+	struct timespec wait[2];
+	int ind = 0;
+
+	wait[0].tv_sec = 0;
+	if (us >= US_PER_S) {
+		wait[0].tv_sec = us / US_PER_S;
+		us -= wait[0].tv_sec * US_PER_S;
+	}
+	wait[0].tv_nsec = 1000 * us;
+
+	while (nanosleep(&wait[ind], &wait[1 - ind]) && errno == EINTR) {
+		/*
+		 * Sleep was interrupted. Flip the index, so the 'remainder'
+		 * will become the 'request' for a next call.
+		 */
+		ind = 1 - ind;
+	}
+}
+
diff --git a/lib/librte_eal/unix/meson.build b/lib/librte_eal/unix/meson.build
index 50c019a56..9da601658 100644
--- a/lib/librte_eal/unix/meson.build
+++ b/lib/librte_eal/unix/meson.build
@@ -4,4 +4,5 @@
 sources += files(
 	'eal.c',
 	'eal_memory.c',
+	'eal_timer.c',
 )
-- 
2.16.1.windows.4

[dpdk-dev] [PATCH v2 2/2] timer: support EAL functions on Windows

[Fady Bader]

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      | 68 +++++++++++++++++++++++++++++++++
 lib/librte_eal/windows/include/rte_os.h |  2 +
 lib/librte_eal/windows/meson.build      |  1 +
 5 files changed, 78 insertions(+)
 create mode 100644 lib/librte_eal/windows/eal_timer.c

diff --git a/lib/librte_eal/common/meson.build b/lib/librte_eal/common/meson.build
index 6dcdcc890..532330e6d 100644
--- a/lib/librte_eal/common/meson.build
+++ b/lib/librte_eal/common/meson.build
@@ -20,6 +20,7 @@ if is_windows
 		'eal_common_options.c',
 		'eal_common_tailqs.c',
 		'eal_common_thread.c',
+		'eal_common_timer.c',
 		'malloc_elem.c',
 		'malloc_heap.c',
 		'rte_malloc.c',
diff --git a/lib/librte_eal/windows/eal.c b/lib/librte_eal/windows/eal.c
index 38f17f09c..32853fbac 100644
--- a/lib/librte_eal/windows/eal.c
+++ b/lib/librte_eal/windows/eal.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) {
diff --git a/lib/librte_eal/windows/eal_timer.c b/lib/librte_eal/windows/eal_timer.c
new file mode 100644
index 000000000..749cc9074
--- /dev/null
+++ b/lib/librte_eal/windows/eal_timer.c
@@ -0,0 +1,68 @@
+/* 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>
+
+/* 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 li_due_time;
+	/* create waitable timer */
+	timer = CreateWaitableTimer(NULL, TRUE, NULL);
+	if (!timer) {
+		RTE_LOG_WIN32_ERR("CreateWaitableTimer()");
+		rte_errno = ENOMEM;
+		return;
+	}
+
+	/* set us microseconds time for timer */
+	li_due_time.QuadPart = -(us * 10);
+	if (!SetWaitableTimer(timer, &li_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)
+{
+	uint64_t tsc_freq;
+	LARGE_INTEGER Frequency;
+
+	QueryPerformanceFrequency(&Frequency);
+
+	/*
+	 * Mulitply by 1K to obtain the true frequency of the CPU
+	 * it was noted in the MSDN "in many cases, QueryPerformanceFrequency
+	 * returns the TSC frequency divided by 1024"
+	 */
+	tsc_freq = ((uint64_t)Frequency.QuadPart * 1024);
+
+	return tsc_freq;
+}
+
+
+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 62805a307..3b63a37cb 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 0bd56cd8f..769cde797 100644
--- a/lib/librte_eal/windows/meson.build
+++ b/lib/librte_eal/windows/meson.build
@@ -12,6 +12,7 @@ sources += files(
 	'eal_memory.c',
 	'eal_mp.c',
 	'eal_thread.c',
+	'eal_timer.c',
 	'getopt.c',
 )
 
-- 
2.16.1.windows.4

Re: [dpdk-dev] [PATCH v2 2/2] timer: support EAL functions on Windows

[Dmitry Kozlyuk]

On 2020-04-27 15:20 GMT+0300 Fady Bader wrote:
> Implemented the needed Windows eal timer functions.
[snip]
> +void
> +rte_delay_us_sleep(unsigned int us)
> +{
> +	HANDLE timer;
> +	LARGE_INTEGER li_due_time;

Here usually comes a blank line.

> +	/* create waitable timer */
> +	timer = CreateWaitableTimer(NULL, TRUE, NULL);
> +	if (!timer) {
> +		RTE_LOG_WIN32_ERR("CreateWaitableTimer()");
> +		rte_errno = ENOMEM;
> +		return;
> +	}
> +
> +	/* set us microseconds time for timer */
> +	li_due_time.QuadPart = -(us * 10);

The comment is still misleading.

[snip]
> +uint64_t
> +get_tsc_freq(void)
> +{
> +	uint64_t tsc_freq;
> +	LARGE_INTEGER Frequency;
> +
> +	QueryPerformanceFrequency(&Frequency);
> +
> +	/*
> +	 * Mulitply by 1K to obtain the true frequency of the CPU
> +	 * it was noted in the MSDN "in many cases, QueryPerformanceFrequency
> +	 * returns the TSC frequency divided by 1024"
> +	 */
> +	tsc_freq = ((uint64_t)Frequency.QuadPart * 1024);
> +
> +	return tsc_freq;
> +}

Extended quote from MSDN:

	Cases might exist where QueryPerformanceFrequency doesn't return the
	actual frequency of the hardware tick generator. For example, in many
	cases, QueryPerformanceFrequency returns the TSC frequency divided by
	1024; and on Hyper-V, the performance counter frequency is always 10
	MHz when the guest virtual machine runs under a hypervisor that
	implements the hypervisor version 1.0 interface. As a result, don't
	assume that QueryPerformanceFrequency will return the precise TSC
	frequency.

	https://docs.microsoft.com/en-us/windows/win32/sysinfo/acquiring-high-resolution-time-stamps

"In many cases" is pretty vague, we can't distinguish such cases.
Here's what I observe on my QEMU guest ("ticks" is Win32 API, "tsc" is RDTSC):

freq = 100000000 Hz        # note: 100 MHz, not 10 MHz
delta (ticks) = 100401071  # Sleep(1000)
delta (secs)  = 1.004011   # delta (ticks) / freq
delta (tsc) = 3460948332   # roughly CPU clock frequency
tsc / tick  = 34.471229

I suggest measuring a real-time delay with rte_get_tsc_cycles() from arch/
as other EALs do when HPET is not available or configured. This is
discouraged by MSDN, but its reasons seem irrelevant for DPDK.

-- 
Dmitry Kozlyuk