linux_dsm_epyc7002/arch/powerpc/kernel/idle.c
Eric W. Biederman 0b4d414714 [PATCH] sysctl: remove insert_at_head from register_sysctl
The semantic effect of insert_at_head is that it would allow new registered
sysctl entries to override existing sysctl entries of the same name.  Which is
pain for caching and the proc interface never implemented.

I have done an audit and discovered that none of the current users of
register_sysctl care as (excpet for directories) they do not register
duplicate sysctl entries.

So this patch simply removes the support for overriding existing entries in
the sys_sysctl interface since no one uses it or cares and it makes future
enhancments harder.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Corey Minyard <minyard@acm.org>
Cc: Neil Brown <neilb@suse.de>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Jan Kara <jack@ucw.cz>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: David Chinner <dgc@sgi.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-14 08:09:59 -08:00

134 lines
2.9 KiB
C

/*
* Idle daemon for PowerPC. Idle daemon will handle any action
* that needs to be taken when the system becomes idle.
*
* Originally written by Cort Dougan (cort@cs.nmt.edu).
* Subsequent 32-bit hacking by Tom Rini, Armin Kuster,
* Paul Mackerras and others.
*
* iSeries supported added by Mike Corrigan <mikejc@us.ibm.com>
*
* Additional shared processor, SMT, and firmware support
* Copyright (c) 2003 Dave Engebretsen <engebret@us.ibm.com>
*
* 32-bit and 64-bit versions merged by Paul Mackerras <paulus@samba.org>
*
* 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.
*/
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/smp.h>
#include <linux/cpu.h>
#include <linux/sysctl.h>
#include <asm/system.h>
#include <asm/processor.h>
#include <asm/cputable.h>
#include <asm/time.h>
#include <asm/machdep.h>
#include <asm/smp.h>
#ifdef CONFIG_HOTPLUG_CPU
#define cpu_should_die() (cpu_is_offline(smp_processor_id()) && \
system_state == SYSTEM_RUNNING)
#else
#define cpu_should_die() 0
#endif
static int __init powersave_off(char *arg)
{
ppc_md.power_save = NULL;
return 0;
}
__setup("powersave=off", powersave_off);
/*
* The body of the idle task.
*/
void cpu_idle(void)
{
if (ppc_md.idle_loop)
ppc_md.idle_loop(); /* doesn't return */
set_thread_flag(TIF_POLLING_NRFLAG);
while (1) {
while (!need_resched() && !cpu_should_die()) {
ppc64_runlatch_off();
if (ppc_md.power_save) {
clear_thread_flag(TIF_POLLING_NRFLAG);
/*
* smp_mb is so clearing of TIF_POLLING_NRFLAG
* is ordered w.r.t. need_resched() test.
*/
smp_mb();
local_irq_disable();
/* check again after disabling irqs */
if (!need_resched() && !cpu_should_die())
ppc_md.power_save();
local_irq_enable();
set_thread_flag(TIF_POLLING_NRFLAG);
} else {
/*
* Go into low thread priority and possibly
* low power mode.
*/
HMT_low();
HMT_very_low();
}
}
HMT_medium();
ppc64_runlatch_on();
if (cpu_should_die())
cpu_die();
preempt_enable_no_resched();
schedule();
preempt_disable();
}
}
int powersave_nap;
#ifdef CONFIG_SYSCTL
/*
* Register the sysctl to set/clear powersave_nap.
*/
static ctl_table powersave_nap_ctl_table[]={
{
.ctl_name = KERN_PPC_POWERSAVE_NAP,
.procname = "powersave-nap",
.data = &powersave_nap,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{}
};
static ctl_table powersave_nap_sysctl_root[] = {
{
.ctl_name = CTL_KERN,
.procname = "kernel",
.mode = 0755,
.child = powersave_nap_ctl_table,
},
{}
};
static int __init
register_powersave_nap_sysctl(void)
{
register_sysctl_table(powersave_nap_sysctl_root);
return 0;
}
__initcall(register_powersave_nap_sysctl);
#endif