/* * IndyDog 0.3 A Hardware Watchdog Device for SGI IP22 * * (c) Copyright 2002 Guido Guenther , * All Rights Reserved. * * 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. * * based on softdog.c by Alan Cox */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include static unsigned long indydog_alive; static DEFINE_SPINLOCK(indydog_lock); #define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */ static bool nowayout = WATCHDOG_NOWAYOUT; module_param(nowayout, bool, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); static void indydog_start(void) { spin_lock(&indydog_lock); sgimc->cpuctrl0 |= SGIMC_CCTRL0_WDOG; spin_unlock(&indydog_lock); } static void indydog_stop(void) { spin_lock(&indydog_lock); sgimc->cpuctrl0 &= ~SGIMC_CCTRL0_WDOG; spin_unlock(&indydog_lock); pr_info("Stopped watchdog timer\n"); } static void indydog_ping(void) { sgimc->watchdogt = 0; } /* * Allow only one person to hold it open */ static int indydog_open(struct inode *inode, struct file *file) { if (test_and_set_bit(0, &indydog_alive)) return -EBUSY; if (nowayout) __module_get(THIS_MODULE); /* Activate timer */ indydog_start(); indydog_ping(); pr_info("Started watchdog timer\n"); return nonseekable_open(inode, file); } static int indydog_release(struct inode *inode, struct file *file) { /* Shut off the timer. * Lock it in if it's a module and we defined ...NOWAYOUT */ if (!nowayout) indydog_stop(); /* Turn the WDT off */ clear_bit(0, &indydog_alive); return 0; } static ssize_t indydog_write(struct file *file, const char *data, size_t len, loff_t *ppos) { /* Refresh the timer. */ if (len) indydog_ping(); return len; } static long indydog_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { int options, retval = -EINVAL; static const struct watchdog_info ident = { .options = WDIOF_KEEPALIVEPING, .firmware_version = 0, .identity = "Hardware Watchdog for SGI IP22", }; switch (cmd) { case WDIOC_GETSUPPORT: if (copy_to_user((struct watchdog_info *)arg, &ident, sizeof(ident))) return -EFAULT; return 0; case WDIOC_GETSTATUS: case WDIOC_GETBOOTSTATUS: return put_user(0, (int *)arg); case WDIOC_SETOPTIONS: { if (get_user(options, (int *)arg)) return -EFAULT; if (options & WDIOS_DISABLECARD) { indydog_stop(); retval = 0; } if (options & WDIOS_ENABLECARD) { indydog_start(); retval = 0; } return retval; } case WDIOC_KEEPALIVE: indydog_ping(); return 0; case WDIOC_GETTIMEOUT: return put_user(WATCHDOG_TIMEOUT, (int *)arg); default: return -ENOTTY; } } static int indydog_notify_sys(struct notifier_block *this, unsigned long code, void *unused) { if (code == SYS_DOWN || code == SYS_HALT) indydog_stop(); /* Turn the WDT off */ return NOTIFY_DONE; } static const struct file_operations indydog_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .write = indydog_write, .unlocked_ioctl = indydog_ioctl, .open = indydog_open, .release = indydog_release, }; static struct miscdevice indydog_miscdev = { .minor = WATCHDOG_MINOR, .name = "watchdog", .fops = &indydog_fops, }; static struct notifier_block indydog_notifier = { .notifier_call = indydog_notify_sys, }; static int __init watchdog_init(void) { int ret; ret = register_reboot_notifier(&indydog_notifier); if (ret) { pr_err("cannot register reboot notifier (err=%d)\n", ret); return ret; } ret = misc_register(&indydog_miscdev); if (ret) { pr_err("cannot register miscdev on minor=%d (err=%d)\n", WATCHDOG_MINOR, ret); unregister_reboot_notifier(&indydog_notifier); return ret; } pr_info("Hardware Watchdog Timer for SGI IP22: 0.3\n"); return 0; } static void __exit watchdog_exit(void) { misc_deregister(&indydog_miscdev); unregister_reboot_notifier(&indydog_notifier); } module_init(watchdog_init); module_exit(watchdog_exit); MODULE_AUTHOR("Guido Guenther "); MODULE_DESCRIPTION("Hardware Watchdog Device for SGI IP22"); MODULE_LICENSE("GPL"); ion value='2'>stat only
authorSteven Rostedt (VMware) <rostedt@goodmis.org>2017-01-30 19:27:10 -0500
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2017-01-31 09:13:49 -0500
commit79c6f448c8b79c321e4a1f31f98194e4f6b6cae7 (patch)
tree370efda701f03cccf21e02bb1fdd3b852547d75c /net/openvswitch/vport.h
parent0c744ea4f77d72b3dcebb7a8f2684633ec79be88 (diff)
tracing: Fix hwlat kthread migration
The hwlat tracer creates a kernel thread at start of the tracer. It is pinned to a single CPU and will move to the next CPU after each period of running. If the user modifies the migration thread's affinity, it will not change after that happens. The original code created the thread at the first instance it was called, but later was changed to destroy the thread after the tracer was finished, and would not be created until the next instance of the tracer was established. The code that initialized the affinity was only called on the initial instantiation of the tracer. After that, it was not initialized, and the previous affinity did not match the current newly created one, making it appear that the user modified the thread's affinity when it did not, and the thread failed to migrate again. Cc: stable@vger.kernel.org Fixes: 0330f7aa8ee6 ("tracing: Have hwlat trace migrate across tracing_cpumask CPUs") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'net/openvswitch/vport.h')