Revision 1e0b5ab81e2abb8bbf7446f4a17f43a1e34944fe authored by Robert Hancock on 29 June 2007, 00:52:24 UTC, committed by Jeff Garzik on 02 July 2007, 14:14:02 UTC
The sata_nv driver was missing the change_queue_depth hook in the SCSI host
template which the other NCQ-capable libata drivers had. This made it impossible
to change the queue depth by user request. Add this in.

Signed-off-by: Robert Hancock <hancockr@shaw.ca>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
1 parent 90c9378
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;

	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;
		invalidate_mapping_pages(inode->i_mapping, 0, -1);
	}
	spin_unlock(&inode_lock);
}

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);
}

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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