Revision 883a2dfd6f13eca5aab30f0bcc9a6f1e2f983b1e authored by Linus Torvalds on 09 July 2015, 00:34:51 UTC, committed by Linus Torvalds on 09 July 2015, 00:34:51 UTC
Pull power management and ACPI updates from Rafael Wysocki:
"These are fixes on top of the previous PM+ACPI pull requests
(including one fix for a 4.1 regression) and two commits adding
_CLS-based device enumeration support to the ACPI core and the ATA
subsystem that waited for the latest ACPICA changes to be merged.
Specifics:
- Fix for an ACPI resources management regression introduced during
the 4.1 cycle (that unfortunately went into -stable) effectively
reverting the bad commit along with the recent fixups on top of it
and using an alternative approach to address the underlying issue
(Rafael J Wysocki).
- Fix for a memory leak and an incorrect return value in an error
code path in the ACPI LPSS (Low-Power Subsystem) driver (Rafael J
Wysocki).
- Fix for a leftover dangling pointer in an error code path in the
new wakeup IRQ support code (Rafael J Wysocki).
- Fix to prevent infinite loops (due to errors in other places) from
happening in the core generic PM domains support code (Geert
Uytterhoeven).
- Hibernation documentation update/clarification (Uwe Geuder).
- Support for _CLS-based device enumeration in the ACPI core and in
the ATA subsystem (Suravee Suthikulpanit)"
* tag 'pm+acpi-4.2-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
PM / wakeirq: Avoid setting power.wakeirq too hastily
ata: ahci_platform: Add ACPI _CLS matching
ACPI / scan: Add support for ACPI _CLS device matching
PM / hibernate: clarify resume documentation
PM / Domains: Avoid infinite loops in attach/detach code
ACPI / LPSS: Fix up acpi_lpss_create_device()
ACPI / PNP: Reserve ACPI resources at the fs_initcall_sync stage
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>
#include "internal.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, void *unused)
{
struct inode *inode, *toput_inode = NULL;
spin_lock(&inode_sb_list_lock);
list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
spin_lock(&inode->i_lock);
if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) ||
(inode->i_mapping->nrpages == 0)) {
spin_unlock(&inode->i_lock);
continue;
}
__iget(inode);
spin_unlock(&inode->i_lock);
spin_unlock(&inode_sb_list_lock);
invalidate_mapping_pages(inode->i_mapping, 0, -1);
iput(toput_inode);
toput_inode = inode;
spin_lock(&inode_sb_list_lock);
}
spin_unlock(&inode_sb_list_lock);
iput(toput_inode);
}
int drop_caches_sysctl_handler(struct ctl_table *table, int write,
void __user *buffer, size_t *length, loff_t *ppos)
{
int ret;
ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
if (ret)
return ret;
if (write) {
static int stfu;
if (sysctl_drop_caches & 1) {
iterate_supers(drop_pagecache_sb, NULL);
count_vm_event(DROP_PAGECACHE);
}
if (sysctl_drop_caches & 2) {
drop_slab();
count_vm_event(DROP_SLAB);
}
if (!stfu) {
pr_info("%s (%d): drop_caches: %d\n",
current->comm, task_pid_nr(current),
sysctl_drop_caches);
}
stfu |= sysctl_drop_caches & 4;
}
return 0;
}
Computing file changes ...
