0793a61d4d
Implement the core kernel bits of Performance Counters subsystem.
The Linux Performance Counter subsystem provides an abstraction of
performance counter hardware capabilities. It provides per task and per
CPU counters, and it provides event capabilities on top of those.
Performance counters are accessed via special file descriptors.
There's one file descriptor per virtual counter used.
The special file descriptor is opened via the perf_counter_open()
system call:
int
perf_counter_open(u32 hw_event_type,
u32 hw_event_period,
u32 record_type,
pid_t pid,
int cpu);
The syscall returns the new fd. The fd can be used via the normal
VFS system calls: read() can be used to read the counter, fcntl()
can be used to set the blocking mode, etc.
Multiple counters can be kept open at a time, and the counters
can be poll()ed.
See more details in Documentation/perf-counters.txt.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
569 lines
14 KiB
C
569 lines
14 KiB
C
/* -*- linux-c -*-
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*
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* $Id: sysrq.c,v 1.15 1998/08/23 14:56:41 mj Exp $
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*
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* Linux Magic System Request Key Hacks
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*
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* (c) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
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* based on ideas by Pavel Machek <pavel@atrey.karlin.mff.cuni.cz>
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*
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* (c) 2000 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
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* overhauled to use key registration
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* based upon discusions in irc://irc.openprojects.net/#kernelnewbies
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*/
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#include <linux/sched.h>
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#include <linux/interrupt.h>
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#include <linux/mm.h>
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#include <linux/fs.h>
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#include <linux/tty.h>
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#include <linux/mount.h>
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#include <linux/kdev_t.h>
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#include <linux/major.h>
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#include <linux/reboot.h>
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#include <linux/sysrq.h>
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#include <linux/kbd_kern.h>
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#include <linux/proc_fs.h>
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#include <linux/quotaops.h>
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#include <linux/perf_counter.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/suspend.h>
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#include <linux/writeback.h>
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#include <linux/buffer_head.h> /* for fsync_bdev() */
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#include <linux/swap.h>
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#include <linux/spinlock.h>
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#include <linux/vt_kern.h>
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#include <linux/workqueue.h>
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#include <linux/kexec.h>
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#include <linux/irq.h>
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#include <linux/hrtimer.h>
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#include <linux/oom.h>
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#include <asm/ptrace.h>
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#include <asm/irq_regs.h>
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/* Whether we react on sysrq keys or just ignore them */
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int __read_mostly __sysrq_enabled = 1;
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static int __read_mostly sysrq_always_enabled;
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int sysrq_on(void)
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{
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return __sysrq_enabled || sysrq_always_enabled;
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}
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/*
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* A value of 1 means 'all', other nonzero values are an op mask:
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*/
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static inline int sysrq_on_mask(int mask)
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{
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return sysrq_always_enabled || __sysrq_enabled == 1 ||
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(__sysrq_enabled & mask);
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}
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static int __init sysrq_always_enabled_setup(char *str)
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{
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sysrq_always_enabled = 1;
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printk(KERN_INFO "debug: sysrq always enabled.\n");
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return 1;
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}
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__setup("sysrq_always_enabled", sysrq_always_enabled_setup);
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static void sysrq_handle_loglevel(int key, struct tty_struct *tty)
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{
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int i;
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i = key - '0';
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console_loglevel = 7;
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printk("Loglevel set to %d\n", i);
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console_loglevel = i;
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}
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static struct sysrq_key_op sysrq_loglevel_op = {
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.handler = sysrq_handle_loglevel,
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.help_msg = "loglevel0-8",
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.action_msg = "Changing Loglevel",
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.enable_mask = SYSRQ_ENABLE_LOG,
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};
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#ifdef CONFIG_VT
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static void sysrq_handle_SAK(int key, struct tty_struct *tty)
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{
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struct work_struct *SAK_work = &vc_cons[fg_console].SAK_work;
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schedule_work(SAK_work);
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}
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static struct sysrq_key_op sysrq_SAK_op = {
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.handler = sysrq_handle_SAK,
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.help_msg = "saK",
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.action_msg = "SAK",
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.enable_mask = SYSRQ_ENABLE_KEYBOARD,
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};
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#else
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#define sysrq_SAK_op (*(struct sysrq_key_op *)0)
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#endif
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#ifdef CONFIG_VT
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static void sysrq_handle_unraw(int key, struct tty_struct *tty)
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{
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struct kbd_struct *kbd = &kbd_table[fg_console];
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if (kbd)
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kbd->kbdmode = default_utf8 ? VC_UNICODE : VC_XLATE;
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}
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static struct sysrq_key_op sysrq_unraw_op = {
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.handler = sysrq_handle_unraw,
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.help_msg = "unRaw",
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.action_msg = "Keyboard mode set to system default",
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.enable_mask = SYSRQ_ENABLE_KEYBOARD,
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};
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#else
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#define sysrq_unraw_op (*(struct sysrq_key_op *)0)
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#endif /* CONFIG_VT */
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#ifdef CONFIG_KEXEC
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static void sysrq_handle_crashdump(int key, struct tty_struct *tty)
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{
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crash_kexec(get_irq_regs());
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}
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static struct sysrq_key_op sysrq_crashdump_op = {
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.handler = sysrq_handle_crashdump,
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.help_msg = "Crashdump",
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.action_msg = "Trigger a crashdump",
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.enable_mask = SYSRQ_ENABLE_DUMP,
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};
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#else
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#define sysrq_crashdump_op (*(struct sysrq_key_op *)0)
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#endif
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static void sysrq_handle_reboot(int key, struct tty_struct *tty)
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{
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lockdep_off();
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local_irq_enable();
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emergency_restart();
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}
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static struct sysrq_key_op sysrq_reboot_op = {
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.handler = sysrq_handle_reboot,
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.help_msg = "reBoot",
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.action_msg = "Resetting",
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.enable_mask = SYSRQ_ENABLE_BOOT,
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};
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static void sysrq_handle_sync(int key, struct tty_struct *tty)
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{
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emergency_sync();
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}
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static struct sysrq_key_op sysrq_sync_op = {
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.handler = sysrq_handle_sync,
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.help_msg = "Sync",
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.action_msg = "Emergency Sync",
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.enable_mask = SYSRQ_ENABLE_SYNC,
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};
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static void sysrq_handle_show_timers(int key, struct tty_struct *tty)
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{
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sysrq_timer_list_show();
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}
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static struct sysrq_key_op sysrq_show_timers_op = {
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.handler = sysrq_handle_show_timers,
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.help_msg = "show-all-timers(Q)",
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.action_msg = "Show clockevent devices & pending hrtimers (no others)",
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};
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static void sysrq_handle_mountro(int key, struct tty_struct *tty)
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{
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emergency_remount();
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}
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static struct sysrq_key_op sysrq_mountro_op = {
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.handler = sysrq_handle_mountro,
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.help_msg = "Unmount",
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.action_msg = "Emergency Remount R/O",
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.enable_mask = SYSRQ_ENABLE_REMOUNT,
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};
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#ifdef CONFIG_LOCKDEP
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static void sysrq_handle_showlocks(int key, struct tty_struct *tty)
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{
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debug_show_all_locks();
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}
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static struct sysrq_key_op sysrq_showlocks_op = {
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.handler = sysrq_handle_showlocks,
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.help_msg = "show-all-locks(D)",
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.action_msg = "Show Locks Held",
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};
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#else
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#define sysrq_showlocks_op (*(struct sysrq_key_op *)0)
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#endif
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#ifdef CONFIG_SMP
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static DEFINE_SPINLOCK(show_lock);
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static void showacpu(void *dummy)
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{
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unsigned long flags;
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/* Idle CPUs have no interesting backtrace. */
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if (idle_cpu(smp_processor_id()))
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return;
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spin_lock_irqsave(&show_lock, flags);
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printk(KERN_INFO "CPU%d:\n", smp_processor_id());
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show_stack(NULL, NULL);
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spin_unlock_irqrestore(&show_lock, flags);
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}
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static void sysrq_showregs_othercpus(struct work_struct *dummy)
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{
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smp_call_function(showacpu, NULL, 0);
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}
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static DECLARE_WORK(sysrq_showallcpus, sysrq_showregs_othercpus);
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static void sysrq_handle_showallcpus(int key, struct tty_struct *tty)
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{
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struct pt_regs *regs = get_irq_regs();
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if (regs) {
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printk(KERN_INFO "CPU%d:\n", smp_processor_id());
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show_regs(regs);
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}
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schedule_work(&sysrq_showallcpus);
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}
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static struct sysrq_key_op sysrq_showallcpus_op = {
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.handler = sysrq_handle_showallcpus,
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.help_msg = "aLlcpus",
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.action_msg = "Show backtrace of all active CPUs",
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.enable_mask = SYSRQ_ENABLE_DUMP,
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};
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#endif
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static void sysrq_handle_showregs(int key, struct tty_struct *tty)
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{
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struct pt_regs *regs = get_irq_regs();
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if (regs)
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show_regs(regs);
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perf_counter_print_debug();
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}
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static struct sysrq_key_op sysrq_showregs_op = {
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.handler = sysrq_handle_showregs,
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.help_msg = "showPc",
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.action_msg = "Show Regs",
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.enable_mask = SYSRQ_ENABLE_DUMP,
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};
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static void sysrq_handle_showstate(int key, struct tty_struct *tty)
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{
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show_state();
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}
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static struct sysrq_key_op sysrq_showstate_op = {
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.handler = sysrq_handle_showstate,
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.help_msg = "showTasks",
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.action_msg = "Show State",
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.enable_mask = SYSRQ_ENABLE_DUMP,
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};
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static void sysrq_handle_showstate_blocked(int key, struct tty_struct *tty)
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{
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show_state_filter(TASK_UNINTERRUPTIBLE);
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}
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static struct sysrq_key_op sysrq_showstate_blocked_op = {
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.handler = sysrq_handle_showstate_blocked,
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.help_msg = "shoW-blocked-tasks",
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.action_msg = "Show Blocked State",
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.enable_mask = SYSRQ_ENABLE_DUMP,
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};
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static void sysrq_handle_showmem(int key, struct tty_struct *tty)
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{
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show_mem();
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}
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static struct sysrq_key_op sysrq_showmem_op = {
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.handler = sysrq_handle_showmem,
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.help_msg = "showMem",
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.action_msg = "Show Memory",
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.enable_mask = SYSRQ_ENABLE_DUMP,
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};
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/*
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* Signal sysrq helper function. Sends a signal to all user processes.
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*/
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static void send_sig_all(int sig)
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{
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struct task_struct *p;
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for_each_process(p) {
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if (p->mm && !is_global_init(p))
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/* Not swapper, init nor kernel thread */
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force_sig(sig, p);
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}
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}
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static void sysrq_handle_term(int key, struct tty_struct *tty)
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{
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send_sig_all(SIGTERM);
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console_loglevel = 8;
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}
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static struct sysrq_key_op sysrq_term_op = {
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.handler = sysrq_handle_term,
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.help_msg = "tErm",
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.action_msg = "Terminate All Tasks",
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.enable_mask = SYSRQ_ENABLE_SIGNAL,
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};
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static void moom_callback(struct work_struct *ignored)
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{
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out_of_memory(node_zonelist(0, GFP_KERNEL), GFP_KERNEL, 0);
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}
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static DECLARE_WORK(moom_work, moom_callback);
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static void sysrq_handle_moom(int key, struct tty_struct *tty)
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{
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schedule_work(&moom_work);
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}
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static struct sysrq_key_op sysrq_moom_op = {
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.handler = sysrq_handle_moom,
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.help_msg = "Full",
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.action_msg = "Manual OOM execution",
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.enable_mask = SYSRQ_ENABLE_SIGNAL,
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};
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static void sysrq_handle_kill(int key, struct tty_struct *tty)
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{
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send_sig_all(SIGKILL);
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console_loglevel = 8;
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}
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static struct sysrq_key_op sysrq_kill_op = {
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.handler = sysrq_handle_kill,
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.help_msg = "kIll",
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.action_msg = "Kill All Tasks",
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.enable_mask = SYSRQ_ENABLE_SIGNAL,
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};
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static void sysrq_handle_unrt(int key, struct tty_struct *tty)
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{
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normalize_rt_tasks();
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}
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static struct sysrq_key_op sysrq_unrt_op = {
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.handler = sysrq_handle_unrt,
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.help_msg = "Nice",
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.action_msg = "Nice All RT Tasks",
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.enable_mask = SYSRQ_ENABLE_RTNICE,
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};
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/* Key Operations table and lock */
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static DEFINE_SPINLOCK(sysrq_key_table_lock);
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static struct sysrq_key_op *sysrq_key_table[36] = {
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&sysrq_loglevel_op, /* 0 */
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&sysrq_loglevel_op, /* 1 */
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&sysrq_loglevel_op, /* 2 */
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&sysrq_loglevel_op, /* 3 */
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&sysrq_loglevel_op, /* 4 */
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&sysrq_loglevel_op, /* 5 */
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&sysrq_loglevel_op, /* 6 */
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&sysrq_loglevel_op, /* 7 */
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&sysrq_loglevel_op, /* 8 */
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&sysrq_loglevel_op, /* 9 */
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/*
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* a: Don't use for system provided sysrqs, it is handled specially on
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* sparc and will never arrive.
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*/
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NULL, /* a */
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&sysrq_reboot_op, /* b */
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&sysrq_crashdump_op, /* c & ibm_emac driver debug */
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&sysrq_showlocks_op, /* d */
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&sysrq_term_op, /* e */
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&sysrq_moom_op, /* f */
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/* g: May be registered by ppc for kgdb */
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NULL, /* g */
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NULL, /* h */
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&sysrq_kill_op, /* i */
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NULL, /* j */
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&sysrq_SAK_op, /* k */
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#ifdef CONFIG_SMP
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&sysrq_showallcpus_op, /* l */
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#else
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NULL, /* l */
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#endif
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&sysrq_showmem_op, /* m */
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&sysrq_unrt_op, /* n */
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/* o: This will often be registered as 'Off' at init time */
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NULL, /* o */
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&sysrq_showregs_op, /* p */
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&sysrq_show_timers_op, /* q */
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&sysrq_unraw_op, /* r */
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&sysrq_sync_op, /* s */
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&sysrq_showstate_op, /* t */
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&sysrq_mountro_op, /* u */
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/* v: May be registered at init time by SMP VOYAGER */
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NULL, /* v */
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&sysrq_showstate_blocked_op, /* w */
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/* x: May be registered on ppc/powerpc for xmon */
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NULL, /* x */
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/* y: May be registered on sparc64 for global register dump */
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NULL, /* y */
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NULL /* z */
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};
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/* key2index calculation, -1 on invalid index */
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static int sysrq_key_table_key2index(int key)
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{
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int retval;
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if ((key >= '0') && (key <= '9'))
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retval = key - '0';
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else if ((key >= 'a') && (key <= 'z'))
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retval = key + 10 - 'a';
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else
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retval = -1;
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return retval;
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}
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/*
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* get and put functions for the table, exposed to modules.
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*/
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struct sysrq_key_op *__sysrq_get_key_op(int key)
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{
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struct sysrq_key_op *op_p = NULL;
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int i;
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i = sysrq_key_table_key2index(key);
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if (i != -1)
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op_p = sysrq_key_table[i];
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return op_p;
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}
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static void __sysrq_put_key_op(int key, struct sysrq_key_op *op_p)
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{
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int i = sysrq_key_table_key2index(key);
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if (i != -1)
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sysrq_key_table[i] = op_p;
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}
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/*
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* This is the non-locking version of handle_sysrq. It must/can only be called
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* by sysrq key handlers, as they are inside of the lock
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*/
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void __handle_sysrq(int key, struct tty_struct *tty, int check_mask)
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{
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struct sysrq_key_op *op_p;
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int orig_log_level;
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int i;
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unsigned long flags;
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spin_lock_irqsave(&sysrq_key_table_lock, flags);
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orig_log_level = console_loglevel;
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console_loglevel = 7;
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printk(KERN_INFO "SysRq : ");
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op_p = __sysrq_get_key_op(key);
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if (op_p) {
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/*
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* Should we check for enabled operations (/proc/sysrq-trigger
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* should not) and is the invoked operation enabled?
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*/
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if (!check_mask || sysrq_on_mask(op_p->enable_mask)) {
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printk("%s\n", op_p->action_msg);
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console_loglevel = orig_log_level;
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op_p->handler(key, tty);
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} else {
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printk("This sysrq operation is disabled.\n");
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}
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} else {
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printk("HELP : ");
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/* Only print the help msg once per handler */
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for (i = 0; i < ARRAY_SIZE(sysrq_key_table); i++) {
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if (sysrq_key_table[i]) {
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int j;
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|
|
for (j = 0; sysrq_key_table[i] !=
|
|
sysrq_key_table[j]; j++)
|
|
;
|
|
if (j != i)
|
|
continue;
|
|
printk("%s ", sysrq_key_table[i]->help_msg);
|
|
}
|
|
}
|
|
printk("\n");
|
|
console_loglevel = orig_log_level;
|
|
}
|
|
spin_unlock_irqrestore(&sysrq_key_table_lock, flags);
|
|
}
|
|
|
|
/*
|
|
* This function is called by the keyboard handler when SysRq is pressed
|
|
* and any other keycode arrives.
|
|
*/
|
|
void handle_sysrq(int key, struct tty_struct *tty)
|
|
{
|
|
if (sysrq_on())
|
|
__handle_sysrq(key, tty, 1);
|
|
}
|
|
EXPORT_SYMBOL(handle_sysrq);
|
|
|
|
static int __sysrq_swap_key_ops(int key, struct sysrq_key_op *insert_op_p,
|
|
struct sysrq_key_op *remove_op_p)
|
|
{
|
|
|
|
int retval;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&sysrq_key_table_lock, flags);
|
|
if (__sysrq_get_key_op(key) == remove_op_p) {
|
|
__sysrq_put_key_op(key, insert_op_p);
|
|
retval = 0;
|
|
} else {
|
|
retval = -1;
|
|
}
|
|
spin_unlock_irqrestore(&sysrq_key_table_lock, flags);
|
|
return retval;
|
|
}
|
|
|
|
int register_sysrq_key(int key, struct sysrq_key_op *op_p)
|
|
{
|
|
return __sysrq_swap_key_ops(key, op_p, NULL);
|
|
}
|
|
EXPORT_SYMBOL(register_sysrq_key);
|
|
|
|
int unregister_sysrq_key(int key, struct sysrq_key_op *op_p)
|
|
{
|
|
return __sysrq_swap_key_ops(key, NULL, op_p);
|
|
}
|
|
EXPORT_SYMBOL(unregister_sysrq_key);
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
/*
|
|
* writing 'C' to /proc/sysrq-trigger is like sysrq-C
|
|
*/
|
|
static ssize_t write_sysrq_trigger(struct file *file, const char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
if (count) {
|
|
char c;
|
|
|
|
if (get_user(c, buf))
|
|
return -EFAULT;
|
|
__handle_sysrq(c, NULL, 0);
|
|
}
|
|
return count;
|
|
}
|
|
|
|
static const struct file_operations proc_sysrq_trigger_operations = {
|
|
.write = write_sysrq_trigger,
|
|
};
|
|
|
|
static int __init sysrq_init(void)
|
|
{
|
|
proc_create("sysrq-trigger", S_IWUSR, NULL, &proc_sysrq_trigger_operations);
|
|
return 0;
|
|
}
|
|
module_init(sysrq_init);
|
|
#endif
|