Re: [dpdk-dev] [PATCH v7 3/3] test/ticketlock: add ticket lock test case

["Joyce Kong (Arm Technology China)" <Joyce.Kong@arm.com>]

Hi Konstantin,

> -----Original Message-----
> From: Ananyev, Konstantin <konstantin.ananyev@intel.com>
> Sent: Friday, March 22, 2019 7:39 PM
> To: Joyce Kong (Arm Technology China) <Joyce.Kong@arm.com>;
> dev@dpdk.org
> Cc: nd <nd@arm.com>; stephen@networkplumber.org;
> jerin.jacob@caviumnetworks.com; thomas@monjalon.net; Honnappa
> Nagarahalli <Honnappa.Nagarahalli@arm.com>; Gavin Hu (Arm Technology
> China) <Gavin.Hu@arm.com>
> Subject: RE: [PATCH v7 3/3] test/ticketlock: add ticket lock test case
> 
> 
> 
> >
> > Add test cases for ticket lock, recursive ticket lock, and ticket lock
> > performance.
> >
> > Signed-off-by: Joyce Kong <joyce.kong@arm.com>
> > Reviewed-by: Gavin Hu <gavin.hu@arm.com>
> > Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
> > ---
> >  MAINTAINERS                |   1 +
> >  app/test/Makefile          |   1 +
> >  app/test/autotest_data.py  |   6 +
> >  app/test/meson.build       |   1 +
> >  app/test/test_ticketlock.c | 311
> > +++++++++++++++++++++++++++++++++++++++++++++
> >  5 files changed, 320 insertions(+)
> >  create mode 100644 app/test/test_ticketlock.c
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS index 3521271..b1ed4cc 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -213,6 +213,7 @@ F: app/test/test_bitmap.c  Ticketlock
> >  M: Joyce Kong <joyce.kong@arm.com>
> >  F: lib/librte_eal/common/include/generic/rte_ticketlock.h
> > +F: app/test/test_ticketlock.c
> >
> >  ARM v7
> >  M: Jan Viktorin <viktorin@rehivetech.com> diff --git
> > a/app/test/Makefile b/app/test/Makefile index 89949c2..d6aa28b 100644
> > --- a/app/test/Makefile
> > +++ b/app/test/Makefile
> > @@ -65,6 +65,7 @@ SRCS-y += test_barrier.c  SRCS-y += test_malloc.c
> > SRCS-y += test_cycles.c  SRCS-y += test_spinlock.c
> > +SRCS-y += test_ticketlock.c
> >  SRCS-y += test_memory.c
> >  SRCS-y += test_memzone.c
> >  SRCS-y += test_bitmap.c
> > diff --git a/app/test/autotest_data.py b/app/test/autotest_data.py
> > index 5f87bb9..db25274 100644
> > --- a/app/test/autotest_data.py
> > +++ b/app/test/autotest_data.py
> > @@ -171,6 +171,12 @@
> >          "Report":  None,
> >      },
> >      {
> > +        "Name":    "Ticketlock autotest",
> > +        "Command": "ticketlock_autotest",
> > +        "Func":    ticketlock_autotest,
> > +        "Report":  None,
> > +    }
> > +    {
> >          "Name":    "Byte order autotest",
> >          "Command": "byteorder_autotest",
> >          "Func":    default_autotest,
> > diff --git a/app/test/meson.build b/app/test/meson.build index
> > 05e5dde..ddb4d09 100644
> > --- a/app/test/meson.build
> > +++ b/app/test/meson.build
> > @@ -107,6 +107,7 @@ test_sources = files('commands.c',
> >  	'test_timer.c',
> >  	'test_timer_perf.c',
> >  	'test_timer_racecond.c',
> > +	'test_ticketlock.c',
> >  	'test_version.c',
> >  	'virtual_pmd.c'
> >  )
> > diff --git a/app/test/test_ticketlock.c b/app/test/test_ticketlock.c
> > new file mode 100644 index 0000000..67281ce
> > --- /dev/null
> > +++ b/app/test/test_ticketlock.c
> > @@ -0,0 +1,311 @@
> > +/* SPDX-License-Identifier: BSD-3-Clause
> > + * Copyright(c) 2018-2019 Arm Limited  */
> > +
> > +#include <inttypes.h>
> > +#include <stdint.h>
> > +#include <stdio.h>
> > +#include <string.h>
> > +#include <sys/queue.h>
> > +#include <unistd.h>
> > +
> > +#include <rte_atomic.h>
> > +#include <rte_common.h>
> > +#include <rte_cycles.h>
> > +#include <rte_eal.h>
> > +#include <rte_launch.h>
> > +#include <rte_lcore.h>
> > +#include <rte_memory.h>
> > +#include <rte_per_lcore.h>
> > +#include <rte_ticketlock.h>
> > +
> > +#include "test.h"
> > +
> > +/*
> > + * Ticketlock test
> > + * =============
> > + *
> > + * - There is a global ticketlock and a table of ticketlocks (one per lcore).
> > + *
> > + * - The test function takes all of these locks and launches the
> > + *   ``test_ticketlock_per_core()`` function on each core (except the master).
> > + *
> > + *   - The function takes the global lock, display something, then releases
> > + *     the global lock.
> > + *   - The function takes the per-lcore lock, display something, then
> releases
> > + *     the per-core lock.
> > + *
> > + * - The main function unlocks the per-lcore locks sequentially and
> > + *   waits between each lock. This triggers the display of a message
> > + *   for each core, in the correct order. The autotest script checks that
> > + *   this order is correct.
> > + *
> > + * - A load test is carried out, with all cores attempting to lock a single lock
> > + *   multiple times
> > + */
> > +
> > +static rte_ticketlock_t tl, tl_try;
> > +static rte_ticketlock_t tl_tab[RTE_MAX_LCORE]; static
> > +rte_ticketlock_recursive_t tlr; static unsigned int count;
> > +
> > +static rte_atomic32_t synchro;
> > +
> > +static int
> > +test_ticketlock_per_core(__attribute__((unused)) void *arg) {
> > +	rte_ticketlock_lock(&tl);
> > +	printf("Global lock taken on core %u\n", rte_lcore_id());
> > +	rte_ticketlock_unlock(&tl);
> > +
> > +	rte_ticketlock_lock(&tl_tab[rte_lcore_id()]);
> > +	printf("Hello from core %u !\n", rte_lcore_id());
> > +	rte_ticketlock_unlock(&tl_tab[rte_lcore_id()]);
> > +
> > +	return 0;
> > +}
> 
> I think that's probably no enough for functional testing.
> Need something extra to ensure that it provides correct locking in MT env.
> Probably extend the perf test below to do both?
> Something like that:
> 
> static uint64_t lcount __rte_cache_aligned; static uint64_t
> lcore_count[RTE_MAX_LCORE] __rte_cache_aligned;
> 
> ...
> 
> load_loop_fn(...)
> {
>    ...
>    rte_ticketlock_lock(&lk);
>    lcount++;
>    rte_ticketlock_unlock(&lk);
>    lcore_count[current_lcore]++;
> }
> 
> Then in test_ticketlock_perf() make sure that sum of al lcore_count[] values
> equals to lcount value:
> tcount = 0;
> for (i = 0; i != RTE_DIM(lcore_count); i++)
>    tcount += lcore_count[i];
> 
> if (tcount != lcount)
>   <error>
> 
> Same thought for trylock.
> Konstantin
> 

Got your opinion and will do this in next version.

> > +
> > +static int
> > +test_ticketlock_recursive_per_core(__attribute__((unused)) void *arg)
> > +{
> > +	unsigned int id = rte_lcore_id();
> > +
> > +	rte_ticketlock_recursive_lock(&tlr);
> > +	printf("Global recursive lock taken on core %u - count = %d\n",
> > +	       id, tlr.count);
> > +	rte_ticketlock_recursive_lock(&tlr);
> > +	printf("Global recursive lock taken on core %u - count = %d\n",
> > +	       id, tlr.count);
> > +	rte_ticketlock_recursive_lock(&tlr);
> > +	printf("Global recursive lock taken on core %u - count = %d\n",
> > +	       id, tlr.count);
> > +
> > +	printf("Hello from within recursive locks from core %u !\n", id);
> > +
> > +	rte_ticketlock_recursive_unlock(&tlr);
> > +	printf("Global recursive lock released on core %u - count = %d\n",
> > +	       id, tlr.count);
> > +	rte_ticketlock_recursive_unlock(&tlr);
> > +	printf("Global recursive lock released on core %u - count = %d\n",
> > +	       id, tlr.count);
> > +	rte_ticketlock_recursive_unlock(&tlr);
> > +	printf("Global recursive lock released on core %u - count = %d\n",
> > +	       id, tlr.count);
> > +
> > +	return 0;
> > +}
> > +
> > +static rte_ticketlock_t lk = RTE_TICKETLOCK_INITIALIZER; static
> > +uint64_t lock_count[RTE_MAX_LCORE] = {0};
> > +
> > +#define TIME_MS 100
> > +
> > +static int
> > +load_loop_fn(void *func_param)
> > +{
> > +	uint64_t time_diff = 0, begin;
> > +	uint64_t hz = rte_get_timer_hz();
> > +	uint64_t lcount = 0;
> > +	const int use_lock = *(int *)func_param;
> > +	const unsigned int lcore = rte_lcore_id();
> > +
> > +	/* wait synchro for slaves */
> > +	if (lcore != rte_get_master_lcore())
> > +		while (rte_atomic32_read(&synchro) == 0)
> > +			;
> > +
> > +	begin = rte_get_timer_cycles();
> > +	while (time_diff < hz * TIME_MS / 1000) {
> > +		if (use_lock)
> > +			rte_ticketlock_lock(&lk);
> > +		lcount++;
> > +		if (use_lock)
> > +			rte_ticketlock_unlock(&lk);
> > +		/* delay to make lock duty cycle slighlty realistic */
> 
> Probably better to do here the same as in test spinlock patches:
>  - remove delay_us()
> - move
>   time_diff = rte_get_timer_cycles() - begin;  out of the loop and report
> aggregate cycles.
> 

Will do the same as test spinlock patches in next version.

> > +		rte_delay_us(1);
> > +		time_diff = rte_get_timer_cycles() - begin;
> > +	}
> > +	lock_count[lcore] = lcount;
> > +	return 0;
> > +}
> > +
> > +static int
> > +test_ticketlock_perf(void)
> > +{
> > +	unsigned int i;
> > +	uint64_t total = 0;
> > +	int lock = 0;
> > +	const unsigned int lcore = rte_lcore_id();
> > +
> > +	printf("\nTest with no lock on single core...\n");
> > +	load_loop_fn(&lock);
> > +	printf("Core [%u] count = %"PRIu64"\n", lcore, lock_count[lcore]);
> > +	memset(lock_count, 0, sizeof(lock_count));
> > +
> > +	printf("\nTest with lock on single core...\n");
> > +	lock = 1;
> > +	load_loop_fn(&lock);
> > +	printf("Core [%u] count = %"PRIu64"\n", lcore, lock_count[lcore]);
> > +	memset(lock_count, 0, sizeof(lock_count));
> > +
> > +	printf("\nTest with lock on %u cores...\n", rte_lcore_count());
> > +
> > +	/* Clear synchro and start slaves */
> > +	rte_atomic32_set(&synchro, 0);
> > +	rte_eal_mp_remote_launch(load_loop_fn, &lock, SKIP_MASTER);
> > +
> > +	/* start synchro and launch test on master */
> > +	rte_atomic32_set(&synchro, 1);
> > +	load_loop_fn(&lock);
> > +
> > +	rte_eal_mp_wait_lcore();
> > +
> > +	RTE_LCORE_FOREACH(i) {
> > +		printf("Core [%u] count = %"PRIu64"\n", i, lock_count[i]);
> > +		total += lock_count[i];
> > +	}
> > +
> > +	printf("Total count = %"PRIu64"\n", total);
> > +
> > +	return 0;
> > +}
> > +
> > +/*
> > + * Use rte_ticketlock_trylock() to trylock a ticketlock object,
> > + * If it could not lock the object successfully, it would
> > + * return immediately and the variable of "count" would be
> > + * increased by one per times. the value of "count" could be
> > + * checked as the result later.
> > + */
> > +static int
> > +test_ticketlock_try(__attribute__((unused)) void *arg) {
> > +	if (rte_ticketlock_trylock(&tl_try) == 0) {
> > +		rte_ticketlock_lock(&tl);
> > +		count++;
> > +		rte_ticketlock_unlock(&tl);
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +
> > +/*
> > + * Test rte_eal_get_lcore_state() in addition to ticketlocks
> > + * as we have "waiting" then "running" lcores.
> > + */
> > +static int
> > +test_ticketlock(void)
> > +{
> > +	int ret = 0;
> > +	int i;
> > +
> > +	/* slave cores should be waiting: print it */
> > +	RTE_LCORE_FOREACH_SLAVE(i) {
> > +		printf("lcore %d state: %d\n", i,
> > +		       (int) rte_eal_get_lcore_state(i));
> > +	}
> > +
> > +	rte_ticketlock_init(&tl);
> > +	rte_ticketlock_init(&tl_try);
> > +	rte_ticketlock_recursive_init(&tlr);
> > +	RTE_LCORE_FOREACH_SLAVE(i) {
> > +		rte_ticketlock_init(&tl_tab[i]);
> > +	}
> > +
> > +	rte_ticketlock_lock(&tl);
> > +
> > +	RTE_LCORE_FOREACH_SLAVE(i) {
> > +		rte_ticketlock_lock(&tl_tab[i]);
> > +		rte_eal_remote_launch(test_ticketlock_per_core, NULL, i);
> > +	}
> > +
> > +	/* slave cores should be busy: print it */
> > +	RTE_LCORE_FOREACH_SLAVE(i) {
> > +		printf("lcore %d state: %d\n", i,
> > +		       (int) rte_eal_get_lcore_state(i));
> > +	}
> > +	rte_ticketlock_unlock(&tl);
> > +
> > +	RTE_LCORE_FOREACH_SLAVE(i) {
> > +		rte_ticketlock_unlock(&tl_tab[i]);
> > +		rte_delay_ms(10);
> > +	}
> > +
> > +	rte_eal_mp_wait_lcore();
> > +
> > +	rte_ticketlock_recursive_lock(&tlr);
> > +
> > +	/*
> > +	 * Try to acquire a lock that we already own
> > +	 */
> > +	if (!rte_ticketlock_recursive_trylock(&tlr)) {
> > +		printf("rte_ticketlock_recursive_trylock failed on a lock that "
> > +		       "we already own\n");
> > +		ret = -1;
> > +	} else
> > +		rte_ticketlock_recursive_unlock(&tlr);
> > +
> > +	RTE_LCORE_FOREACH_SLAVE(i) {
> > +		rte_eal_remote_launch(test_ticketlock_recursive_per_core,
> > +					NULL, i);
> > +	}
> > +	rte_ticketlock_recursive_unlock(&tlr);
> > +	rte_eal_mp_wait_lcore();
> > +
> > +	/*
> > +	 * Test if it could return immediately from try-locking a locked object.
> > +	 * Here it will lock the ticketlock object first, then launch all the
> > +	 * slave lcores to trylock the same ticketlock object.
> > +	 * All the slave lcores should give up try-locking a locked object and
> > +	 * return immediately, and then increase the "count" initialized with
> > +	 * zero by one per times.
> > +	 * We can check if the "count" is finally equal to the number of all
> > +	 * slave lcores to see if the behavior of try-locking a locked
> > +	 * ticketlock object is correct.
> > +	 */
> > +	if (rte_ticketlock_trylock(&tl_try) == 0)
> > +		return -1;
> > +
> > +	count = 0;
> > +	RTE_LCORE_FOREACH_SLAVE(i) {
> > +		rte_eal_remote_launch(test_ticketlock_try, NULL, i);
> > +	}
> > +	rte_eal_mp_wait_lcore();
> > +	rte_ticketlock_unlock(&tl_try);
> > +	if (rte_ticketlock_is_locked(&tl)) {
> > +		printf("ticketlock is locked but it should not be\n");
> > +		return -1;
> > +	}
> > +	rte_ticketlock_lock(&tl);
> > +	if (count != (rte_lcore_count() - 1))
> > +		ret = -1;
> > +
> > +	rte_ticketlock_unlock(&tl);
> > +
> > +	/*
> > +	 * Test if it can trylock recursively.
> > +	 * Use rte_ticketlock_recursive_trylock() to check if it can lock
> > +	 * a ticketlock object recursively. Here it will try to lock a
> > +	 * ticketlock object twice.
> > +	 */
> > +	if (rte_ticketlock_recursive_trylock(&tlr) == 0) {
> > +		printf("It failed to do the first ticketlock_recursive_trylock "
> > +			   "but it should able to do\n");
> > +		return -1;
> > +	}
> > +	if (rte_ticketlock_recursive_trylock(&tlr) == 0) {
> > +		printf("It failed to do the second ticketlock_recursive_trylock
> "
> > +			   "but it should able to do\n");
> > +		return -1;
> > +	}
> > +	rte_ticketlock_recursive_unlock(&tlr);
> > +	rte_ticketlock_recursive_unlock(&tlr);
> > +
> > +	if (test_ticketlock_perf() < 0)
> > +		return -1;
> > +
> > +	return ret;
> > +}
> > +
> > +REGISTER_TEST_COMMAND(ticketlock_autotest, test_ticketlock);
> > --
> > 2.7.4