Messages in this thread Patch in this message | | | From | David Howells <> | Subject | Re: [patch 00/19] mutex subsystem, -V11 | Date | Tue, 03 Jan 2006 15:55:01 +0000 |
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The attached patch adds a module for testing and benchmarking mutexes, semaphores and R/W semaphores.
Using it is simple:
insmod synchro-test.ko <args>
It will exit with error ENOANO after running the tests and printing the results to the kernel console log.
The available arguments are:
(*) mx=N
Start up to N mutex thrashing threads, where N is at most 20. All will try and thrash the same mutex.
(*) sm=N
Start up to N counting semaphore thrashing threads, where N is at most 20. All will try and thrash the same semaphore.
(*) ism=M
Initialise the counting semaphore with M, where M is any positive integer greater than zero. The default is 4.
(*) rd=N (*) wr=O (*) dg=P
Start up to N reader thrashing threads, O writer thrashing threads and P downgrader thrashing threads, where N, O and P are at most 20 apiece. All will try and thrash the same read/write semaphore.
(*) elapse=N
Run the tests for N seconds. The default is 5.
(*) load=N
Each thread delays for N uS whilst holding the lock. The dfault is 0.
(*) do_sched=1
Each thread will call schedule if required after each iteration.
(*) v=1
Print more verbose information, including a thread iteration distribution list.
The module should be enabled by turning on CONFIG_DEBUG_SYNCHRO_TEST to "m".
Signed-Off-By: David Howells <dhowells@redhat.com> --- warthog>diffstat -p1 mutex-debug-module-2615rc7.diff Documentation/synchro-test.txt | 51 ++++ kernel/Makefile | 1 kernel/synchro-test.c | 486 +++++++++++++++++++++++++++++++++++++++++ lib/Kconfig.debug | 14 + 4 files changed, 552 insertions(+)
diff -uNrp linux-2.6.15-rc7-mutex/Documentation/synchro-test.txt linux-2.6.15-rc7-mutex-slowopt/Documentation/synchro-test.txt --- linux-2.6.15-rc7-mutex/Documentation/synchro-test.txt 1970-01-01 01:00:00.000000000 +0100 +++ linux-2.6.15-rc7-mutex-slowopt/Documentation/synchro-test.txt 2006-01-03 15:45:26.000000000 +0000 @@ -0,0 +1,51 @@ +The synchro-test.ko module can be used for testing and benchmarking mutexes, +semaphores and R/W semaphores. + +Using it is simple: + + insmod synchro-test.ko <args> + +It will exit with error ENOANO after running the tests and printing the +results to the kernel console log. + +The available arguments are: + + (*) mx=N + + Start up to N mutex thrashing threads, where N is at most 20. All will + try and thrash the same mutex. + + (*) sm=N + + Start up to N counting semaphore thrashing threads, where N is at most + 20. All will try and thrash the same semaphore. + + (*) ism=M + + Initialise the counting semaphore with M, where M is any positive + integer greater than zero. The default is 4. + + (*) rd=N + (*) wr=O + (*) dg=P + + Start up to N reader thrashing threads, O writer thrashing threads and + P downgrader thrashing threads, where N, O and P are at most 20 + apiece. All will try and thrash the same read/write semaphore. + + (*) elapse=N + + Run the tests for N seconds. The default is 5. + + (*) load=N + + Each thread delays for N uS whilst holding the lock. The dfault is 0. + + (*) do_sched=1 + + Each thread will call schedule if required after each iteration. + + (*) v=1 + + Print more verbose information, including a thread iteration + distribution list. diff -uNrp linux-2.6.15-rc7-mutex/kernel/Makefile linux-2.6.15-rc7-mutex-slowopt/kernel/Makefile --- linux-2.6.15-rc7-mutex/kernel/Makefile 2006-01-03 14:40:06.000000000 +0000 +++ linux-2.6.15-rc7-mutex-slowopt/kernel/Makefile 2006-01-03 15:43:51.000000000 +0000 @@ -33,6 +33,7 @@ obj-$(CONFIG_GENERIC_HARDIRQS) += irq/ obj-$(CONFIG_CRASH_DUMP) += crash_dump.o obj-$(CONFIG_SECCOMP) += seccomp.o obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o +obj-$(CONFIG_DEBUG_SYNCHRO_TEST) += synchro-test.o ifneq ($(CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER),y) # According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is diff -uNrp linux-2.6.15-rc7-mutex/kernel/synchro-test.c linux-2.6.15-rc7-mutex-slowopt/kernel/synchro-test.c --- linux-2.6.15-rc7-mutex/kernel/synchro-test.c 1970-01-01 01:00:00.000000000 +0100 +++ linux-2.6.15-rc7-mutex-slowopt/kernel/synchro-test.c 2006-01-03 15:37:16.000000000 +0000 @@ -0,0 +1,486 @@ +/* synchro-test.c: run some threads to test the synchronisation primitives + * + * Copyright (C) 2005 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * run as something like: + * + * insmod synchro-test.ko rd=2 wr=2 + * insmod synchro-test.ko mx=1 + * insmod synchro-test.ko sm=2 ism=1 + * insmod synchro-test.ko sm=2 ism=2 + */ + +#include <linux/config.h> +#include <linux/module.h> +#include <linux/poll.h> +#include <linux/moduleparam.h> +#include <linux/stat.h> +#include <linux/init.h> +#include <asm/atomic.h> +#include <linux/personality.h> +#include <linux/smp_lock.h> +#include <linux/delay.h> +#include <linux/timer.h> +#include <linux/completion.h> +#include <linux/mutex.h> + +#define VALIDATE_OPERATORS 0 + +static int nummx = 0; +static int numsm = 0, seminit = 4; +static int numrd = 0, numwr = 0, numdg = 0; +static int elapse = 5, load = 0, do_sched = 0; +static int verbose = 0; + +MODULE_AUTHOR("David Howells"); +MODULE_DESCRIPTION("Synchronisation primitive test demo"); +MODULE_LICENSE("GPL"); + +module_param_named(v, verbose, int, 0); +MODULE_PARM_DESC(verbose, "Verbosity"); + +module_param_named(mx, nummx, int, 0); +MODULE_PARM_DESC(nummx, "Number of mutex threads"); + +module_param_named(sm, numsm, int, 0); +MODULE_PARM_DESC(numsm, "Number of semaphore threads"); + +module_param_named(ism, seminit, int, 0); +MODULE_PARM_DESC(seminit, "Initial semaphore value"); + +module_param_named(rd, numrd, int, 0); +MODULE_PARM_DESC(numrd, "Number of reader threads"); + +module_param_named(wr, numwr, int, 0); +MODULE_PARM_DESC(numwr, "Number of writer threads"); + +module_param_named(dg, numdg, int, 0); +MODULE_PARM_DESC(numdg, "Number of downgrader threads"); + +module_param(elapse, int, 0); +MODULE_PARM_DESC(elapse, "Number of seconds to run for"); + +module_param(load, int, 0); +MODULE_PARM_DESC(load, "Length of load in uS"); + +module_param(do_sched, int, 0); +MODULE_PARM_DESC(do_sched, "True if each thread should schedule regularly"); + +/* the semaphores under test */ +static struct mutex ____cacheline_aligned mutex; +static struct semaphore ____cacheline_aligned sem; +static struct rw_semaphore ____cacheline_aligned rwsem; + +static atomic_t ____cacheline_aligned do_stuff = ATOMIC_INIT(0); + +#if VALIDATE_OPERATORS +static atomic_t ____cacheline_aligned mutexes = ATOMIC_INIT(0); +static atomic_t ____cacheline_aligned semaphores = ATOMIC_INIT(0); +static atomic_t ____cacheline_aligned readers = ATOMIC_INIT(0); +static atomic_t ____cacheline_aligned writers = ATOMIC_INIT(0); +#endif + +static unsigned int ____cacheline_aligned mutexes_taken[20]; +static unsigned int ____cacheline_aligned semaphores_taken[20]; +static unsigned int ____cacheline_aligned reads_taken[20]; +static unsigned int ____cacheline_aligned writes_taken[20]; +static unsigned int ____cacheline_aligned downgrades_taken[20]; + +static struct completion ____cacheline_aligned mx_comp[20]; +static struct completion ____cacheline_aligned sm_comp[20]; +static struct completion ____cacheline_aligned rd_comp[20]; +static struct completion ____cacheline_aligned wr_comp[20]; +static struct completion ____cacheline_aligned dg_comp[20]; + +static struct timer_list ____cacheline_aligned timer; + +#define ACCOUNT(var, N) var##_taken[N]++; + +#if VALIDATE_OPERATORS +#define TRACK(var, dir) atomic_##dir(&(var)) + +#define CHECK(var, cond, val) \ +do { \ + int x = atomic_read(&(var)); \ + if (unlikely(!(x cond (val)))) \ + printk("check [%s %s %d, == %d] failed in %s\n", \ + #var, #cond, (val), x, __func__); \ +} while (0) + +#else +#define TRACK(var, dir) do {} while(0) +#define CHECK(var, cond, val) do {} while(0) +#endif + +static inline void do_mutex_lock(unsigned int N) +{ + mutex_lock(&mutex); + + ACCOUNT(mutexes, N); + TRACK(mutexes, inc); + CHECK(mutexes, ==, 1); +} + +static inline void do_mutex_unlock(unsigned int N) +{ + CHECK(mutexes, ==, 1); + TRACK(mutexes, dec); + + mutex_unlock(&mutex); +} + +static inline void do_down(unsigned int N) +{ + CHECK(mutexes, <, seminit); + + down(&sem); + + ACCOUNT(semaphores, N); + TRACK(semaphores, inc); +} + +static inline void do_up(unsigned int N) +{ + CHECK(semaphores, >, 0); + TRACK(semaphores, dec); + + up(&sem); +} + +static inline void do_down_read(unsigned int N) +{ + down_read(&rwsem); + + ACCOUNT(reads, N); + TRACK(readers, inc); + CHECK(readers, >, 0); + CHECK(writers, ==, 0); +} + +static inline void do_up_read(unsigned int N) +{ + CHECK(readers, >, 0); + CHECK(writers, ==, 0); + TRACK(readers, dec); + + up_read(&rwsem); +} + +static inline void do_down_write(unsigned int N) +{ + down_write(&rwsem); + + ACCOUNT(writes, N); + TRACK(writers, inc); + CHECK(writers, ==, 1); + CHECK(readers, ==, 0); +} + +static inline void do_up_write(unsigned int N) +{ + CHECK(writers, ==, 1); + CHECK(readers, ==, 0); + TRACK(writers, dec); + + up_write(&rwsem); +} + +static inline void do_downgrade_write(unsigned int N) +{ + CHECK(writers, ==, 1); + CHECK(readers, ==, 0); + TRACK(writers, dec); + TRACK(readers, inc); + + downgrade_write(&rwsem); + + ACCOUNT(downgrades, N); +} + +static inline void sched(void) +{ + if (do_sched) + schedule(); +} + +int mutexer(void *arg) +{ + unsigned int N = (unsigned long) arg; + + daemonize("Mutex%u", N); + + while (atomic_read(&do_stuff)) { + do_mutex_lock(N); + if (load) + udelay(load); + do_mutex_unlock(N); + sched(); + } + + if (verbose >= 2) + printk("%s: done\n", current->comm); + complete_and_exit(&mx_comp[N], 0); +} + +int semaphorer(void *arg) +{ + unsigned int N = (unsigned long) arg; + + daemonize("Sem%u", N); + + while (atomic_read(&do_stuff)) { + do_down(N); + if (load) + udelay(load); + do_up(N); + sched(); + } + + if (verbose >= 2) + printk("%s: done\n", current->comm); + complete_and_exit(&sm_comp[N], 0); +} + +int reader(void *arg) +{ + unsigned int N = (unsigned long) arg; + + daemonize("Read%u", N); + + while (atomic_read(&do_stuff)) { + do_down_read(N); +#ifdef LOAD_TEST + if (load) + udelay(load); +#endif + do_up_read(N); + sched(); + } + + if (verbose >= 2) + printk("%s: done\n", current->comm); + complete_and_exit(&rd_comp[N], 0); +} + +int writer(void *arg) +{ + unsigned int N = (unsigned long) arg; + + daemonize("Write%u", N); + + while (atomic_read(&do_stuff)) { + do_down_write(N); +#ifdef LOAD_TEST + if (load) + udelay(load); +#endif + do_up_write(N); + sched(); + } + + if (verbose >= 2) + printk("%s: done\n", current->comm); + complete_and_exit(&wr_comp[N], 0); +} + +int downgrader(void *arg) +{ + unsigned int N = (unsigned long) arg; + + daemonize("Down%u", N); + + while (atomic_read(&do_stuff)) { + do_down_write(N); +#ifdef LOAD_TEST + if (load) + udelay(load); +#endif + do_downgrade_write(N); +#ifdef LOAD_TEST + if (load) + udelay(load); +#endif + do_up_read(N); + sched(); + } + + if (verbose >= 2) + printk("%s: done\n", current->comm); + complete_and_exit(&dg_comp[N], 0); +} + +static void stop_test(unsigned long dummy) +{ + atomic_set(&do_stuff, 0); +} + +static unsigned int total(const char *what, unsigned int counts[], int num) +{ + unsigned int tot = 0, max = 0, min = UINT_MAX, zeros = 0, cnt; + int loop; + + for (loop = 0; loop < num; loop++) { + cnt = counts[loop]; + + if (cnt == 0) { + zeros++; + min = 0; + continue; + } + + tot += cnt; + if (tot > max) + max = tot; + if (tot < min) + min = tot; + } + + if (verbose && tot > 0) { + printk("%s:", what); + + for (loop = 0; loop < num; loop++) { + cnt = counts[loop]; + + if (cnt == 0) + printk(" zzz"); + else + printk(" %d%%", cnt * 100 / tot); + } + + printk("\n"); + } + + return tot; +} + +/*****************************************************************************/ +/* + * + */ +static int __init do_tests(void) +{ + unsigned long loop; + unsigned int mutex_total, sem_total, rd_total, wr_total, dg_total; + + if (nummx < 0 || nummx > 20 || + numsm < 0 || numsm > 20 || + numrd < 0 || numrd > 20 || + numwr < 0 || numwr > 20 || + numdg < 0 || numdg > 20 || + seminit < 1 || + elapse < 1 + ) { + printk("Parameter out of range\n"); + return -ERANGE; + } + + if ((nummx | numsm | numrd | numwr | numdg) == 0) { + printk("Nothing to do\n"); + return -EINVAL; + } + + if (verbose) + printk("\nStarting synchronisation primitive tests...\n"); + + mutex_init(&mutex); + sema_init(&sem, seminit); + init_rwsem(&rwsem); + atomic_set(&do_stuff, 1); + + /* kick off all the children */ + for (loop = 0; loop < 20; loop++) { + if (loop < nummx) { + init_completion(&mx_comp[loop]); + kernel_thread(mutexer, (void *) loop, 0); + } + + if (loop < numsm) { + init_completion(&sm_comp[loop]); + kernel_thread(semaphorer, (void *) loop, 0); + } + + if (loop < numrd) { + init_completion(&rd_comp[loop]); + kernel_thread(reader, (void *) loop, 0); + } + + if (loop < numwr) { + init_completion(&wr_comp[loop]); + kernel_thread(writer, (void *) loop, 0); + } + + if (loop < numdg) { + init_completion(&dg_comp[loop]); + kernel_thread(downgrader, (void *) loop, 0); + } + } + + /* set a stop timer */ + init_timer(&timer); + timer.function = stop_test; + timer.expires = jiffies + elapse * HZ; + add_timer(&timer); + + /* now wait until it's all done */ + for (loop = 0; loop < nummx; loop++) + wait_for_completion(&mx_comp[loop]); + + for (loop = 0; loop < numsm; loop++) + wait_for_completion(&sm_comp[loop]); + + for (loop = 0; loop < numrd; loop++) + wait_for_completion(&rd_comp[loop]); + + for (loop = 0; loop < numwr; loop++) + wait_for_completion(&wr_comp[loop]); + + for (loop = 0; loop < numdg; loop++) + wait_for_completion(&dg_comp[loop]); + + atomic_set(&do_stuff, 0); + del_timer(&timer); + + if (mutex_is_locked(&mutex)) + printk(KERN_ERR "Mutex is still locked!\n"); + + /* count up */ + mutex_total = total("MTX", mutexes_taken, nummx); + sem_total = total("SEM", semaphores_taken, numsm); + rd_total = total("RD ", reads_taken, numrd); + wr_total = total("WR ", writes_taken, numwr); + dg_total = total("DG ", downgrades_taken, numdg); + + /* print the results */ + if (verbose) { + printk("mutexes taken: %u\n", mutex_total); + printk("semaphores taken: %u\n", sem_total); + printk("reads taken: %u\n", rd_total); + printk("writes taken: %u\n", wr_total); + printk("downgrades taken: %u\n", dg_total); + } + else { + printk("%3d %3d %3d %3d %3d %c %3d %9u %9u %9u %9u %9u\n", + nummx, numsm, numrd, numwr, numdg, + do_sched ? 's' : '-', + load, + mutex_total, + sem_total, + rd_total, + wr_total, + dg_total); + } + + /* tell insmod to discard the module */ + if (verbose) + printk("Tests complete\n"); + return -ENOANO; + +} /* end do_tests() */ + +module_init(do_tests); diff -uNrp linux-2.6.15-rc7-mutex/lib/Kconfig.debug linux-2.6.15-rc7-mutex-slowopt/lib/Kconfig.debug --- linux-2.6.15-rc7-mutex/lib/Kconfig.debug 2006-01-03 14:40:06.000000000 +0000 +++ linux-2.6.15-rc7-mutex-slowopt/lib/Kconfig.debug 2006-01-03 15:48:23.000000000 +0000 @@ -207,3 +207,17 @@ config RCU_TORTURE_TEST at boot time (you probably don't). Say M if you want the RCU torture tests to build as a module. Say N if you are unsure. + +config DEBUG_SYNCHRO_TEST + tristate "Synchronisation primitive testing module" + depends on DEBUG_KERNEL + default n + help + This option provides a kernel module that can thrash the sleepable + synchronisation primitives (mutexes and semaphores). + + You should say N or M here. Whilst the module can be built in, it's + not recommended as it requires module parameters supplying to get it + to do anything. + + See Documentation/synchro-test.txt. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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