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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2020 Jeffrey Roberson <jeff@FreeBSD.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice unmodified, this list of conditions, and the following
* disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/libkern.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/kthread.h>
#include <sys/conf.h>
#include <sys/mbuf.h>
#include <sys/smp.h>
#include <sys/smr.h>
#include <vm/uma.h>
#include <machine/stdarg.h>
static uma_zone_t smrs_zone;
static smr_t smrs_smr;
static int smrs_cpus;
static int smrs_writers;
static int smrs_started;
static int smrs_iterations = 10000000;
static int smrs_failures = 0;
static volatile int smrs_completed;
struct smrs {
int generation;
volatile u_int count;
};
uintptr_t smrs_current;
static void
smrs_error(struct smrs *smrs, const char *fmt, ...)
{
va_list ap;
atomic_add_int(&smrs_failures, 1);
printf("SMR ERROR: wr_seq %d, rd_seq %d, c_seq %d, generation %d, count %d ",
smrs_smr->c_shared->s_wr.seq, smrs_smr->c_shared->s_rd_seq,
zpcpu_get(smrs_smr)->c_seq, smrs->generation, smrs->count);
va_start(ap, fmt);
(void)vprintf(fmt, ap);
va_end(ap);
}
static void
smrs_read(void)
{
struct smrs *cur;
int cnt;
/* Wait for the writer to exit. */
while (smrs_completed == 0) {
smr_enter(smrs_smr);
cur = (void *)atomic_load_acq_ptr(&smrs_current);
if (cur->generation == -1)
smrs_error(cur, "read early: Use after free!\n");
atomic_add_int(&cur->count, 1);
DELAY(100);
cnt = atomic_fetchadd_int(&cur->count, -1);
if (cur->generation == -1)
smrs_error(cur, "read late: Use after free!\n");
else if (cnt <= 0)
smrs_error(cur, "Invalid ref\n");
smr_exit(smrs_smr);
maybe_yield();
}
}
static void
smrs_write(void)
{
struct smrs *cur;
int i;
for (i = 0; i < smrs_iterations; i++) {
cur = uma_zalloc_smr(smrs_zone, M_WAITOK);
atomic_thread_fence_rel();
cur = (void *)atomic_swap_ptr(&smrs_current, (uintptr_t)cur);
uma_zfree_smr(smrs_zone, cur);
}
}
static void
smrs_thread(void *arg)
{
int rw = (intptr_t)arg;
if (rw < smrs_writers)
smrs_write();
else
smrs_read();
atomic_add_int(&smrs_completed, 1);
}
static void
smrs_start(void)
{
struct smrs *cur;
int i;
smrs_cpus = mp_ncpus;
if (mp_ncpus > 3)
smrs_writers = 2;
else
smrs_writers = 1;
smrs_started = smrs_cpus;
smrs_completed = 0;
atomic_store_rel_ptr(&smrs_current,
(uintptr_t)uma_zalloc_smr(smrs_zone, M_WAITOK));
for (i = 0; i < smrs_started; i++)
kthread_add((void (*)(void *))smrs_thread,
(void *)(intptr_t)i, curproc, NULL, 0, 0, "smrs-%d", i);
while (smrs_completed != smrs_started)
pause("prf", hz/2);
cur = (void *)smrs_current;
smrs_current = (uintptr_t)NULL;
uma_zfree_smr(smrs_zone, cur);
printf("Completed %d loops with %d failures\n",
smrs_iterations, smrs_failures);
}
static int
smrs_ctor(void *mem, int size, void *arg, int flags)
{
static int smr_generation = 0;
struct smrs *smrs = mem;
if (smrs->generation != -1 && smrs->generation != 0)
smrs_error(smrs, "ctor: Invalid smr generation on ctor\n");
else if (smrs->count != 0)
smrs_error(smrs, "ctor: Invalid count\n");
smrs->generation = ++smr_generation;
return (0);
}
static void
smrs_dtor(void *mem, int size, void *arg)
{
struct smrs *smrs = mem;
if (smrs->generation == -1)
smrs_error(smrs, "dtor: Invalid generation");
smrs->generation = -1;
if (smrs->count != 0)
smrs_error(smrs, "dtor: Invalid count\n");
}
static void
smrs_init(void)
{
smrs_zone = uma_zcreate("smrs", sizeof(struct smrs),
smrs_ctor, smrs_dtor, NULL, NULL, UMA_ALIGN_PTR,
UMA_ZONE_SMR | UMA_ZONE_ZINIT);
smrs_smr = uma_zone_get_smr(smrs_zone);
}
static void
smrs_fini(void)
{
uma_zdestroy(smrs_zone);
}
static int
smrs_modevent(module_t mod, int what, void *arg)
{
switch (what) {
case MOD_LOAD:
smrs_init();
smrs_start();
break;
case MOD_UNLOAD:
smrs_fini();
break;
default:
break;
}
return (0);
}
moduledata_t smrs_meta = {
"smrstress",
smrs_modevent,
NULL
};
DECLARE_MODULE(smrstress, smrs_meta, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);
MODULE_VERSION(smrstress, 1);
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