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Revision 1fd684346d41f6be2487c161f60d03a7feb68911 authored by Rafael J. Wysocki on 19 January 2009, 19:57:36 UTC, committed by Jeff Garzik on 27 January 2009, 07:15:51 UTC 
SATA AHCI: Blacklist system that spins off disks during ACPI power off
 
Some notebooks from HP have the problem that their BIOSes attempt to
spin down hard drives before entering ACPI system states S4 and S5.
This leads to a yo-yo effect during system power-off shutdown and the
last phase of hibernation when the disk is first spun down by the
kernel and then almost immediately turned on and off by the BIOS.
This, in turn, may result in shortening the disk's life times.

To prevent this from happening we can blacklist the affected systems
using DMI information.

Blacklist HP nx6310 that uses the AHCI driver.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
1 parent 2a6e58d
Raw File
drop_caches.c 
/*
 * Implement the manual drop-all-pagecache function
 */

#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/writeback.h>
#include <linux/sysctl.h>
#include <linux/gfp.h>

/* A global variable is a bit ugly, but it keeps the code simple */
int sysctl_drop_caches;

static void drop_pagecache_sb(struct super_block *sb)
{
	struct inode *inode, *toput_inode = NULL;

	spin_lock(&inode_lock);
	list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
		if (inode->i_state & (I_FREEING|I_WILL_FREE))
			continue;
		if (inode->i_mapping->nrpages == 0)
			continue;
		__iget(inode);
		spin_unlock(&inode_lock);
		__invalidate_mapping_pages(inode->i_mapping, 0, -1, true);
		iput(toput_inode);
		toput_inode = inode;
		spin_lock(&inode_lock);
	}
	spin_unlock(&inode_lock);
	iput(toput_inode);
}

static void drop_pagecache(void)
{
	struct super_block *sb;

	spin_lock(&sb_lock);
restart:
	list_for_each_entry(sb, &super_blocks, s_list) {
		sb->s_count++;
		spin_unlock(&sb_lock);
		down_read(&sb->s_umount);
		if (sb->s_root)
			drop_pagecache_sb(sb);
		up_read(&sb->s_umount);
		spin_lock(&sb_lock);
		if (__put_super_and_need_restart(sb))
			goto restart;
	}
	spin_unlock(&sb_lock);
}

static void drop_slab(void)
{
	int nr_objects;

	do {
		nr_objects = shrink_slab(1000, GFP_KERNEL, 1000);
	} while (nr_objects > 10);
}

int drop_caches_sysctl_handler(ctl_table *table, int write,
	struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
{
	proc_dointvec_minmax(table, write, file, buffer, length, ppos);
	if (write) {
		if (sysctl_drop_caches & 1)
			drop_pagecache();
		if (sysctl_drop_caches & 2)
			drop_slab();
	}
	return 0;
}
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