提交 · 96e9694df446d1154ec2f4fdba8908588b9cba38 · openanolis / cloud-kernel

27 10月, 2010 40 次提交

hpet: fix unwanted interrupt due to stale irq status bit · 96e9694d

由 Clemens Ladisch 提交于 10月 26, 2010

Jaswinder Singh Rajput wrote:
> By executing Documentation/timers/hpet_example.c
>
> for polling, I requested for 3 iterations but it seems iteration work
> for only 2 as first expired time is always very small.
>
> # ./hpet_example poll /dev/hpet 10 3
> -hpet: executing poll
> hpet_poll: info.hi_flags 0x0
> hpet_poll: expired time = 0x13
> hpet_poll: revents = 0x1
> hpet_poll: data 0x1
> hpet_poll: expired time = 0x1868c
> hpet_poll: revents = 0x1
> hpet_poll: data 0x1
> hpet_poll: expired time = 0x18645
> hpet_poll: revents = 0x1
> hpet_poll: data 0x1

Clearing the HPET interrupt enable bit disables interrupt generation
but does not disable the timer, so the interrupt status bit will still
be set when the timer elapses.  If another interrupt arrives before
the timer has been correctly programmed (due to some other device on
the same interrupt line, or CONFIG_DEBUG_SHIRQ), this results in an
extra unwanted interrupt event because the status bit is likely to be
set from comparator matches that happened before the device was opened.

Therefore, we have to ensure that the interrupt status bit is and
stays cleared until we actually program the timer.
Signed-off-by: NClemens Ladisch <clemens@ladisch.de>
Reported-by: NJaswinder Singh Rajput <jaswinderlinux@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Bob Picco <bpicco@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

96e9694d

hpet: unmap unused I/O space · a56d5318

由 Jiri Slaby 提交于 10月 26, 2010

When the initialization code in hpet finds a memory resource and does not
find an IRQ, it does not unmap the memory resource previously mapped.

There are buggy BIOSes which report resources exactly like this and what
is worse the memory region bases point to normal RAM.  This normally would
not matter since the space is not touched.  But when PAT is turned on,
ioremap causes the page to be uncached and sets this bit in page->flags.

Then when the page is about to be used by the allocator, it is reported
as:

BUG: Bad page state in process md5sum  pfn:3ed00
page:ffffea0000dbd800 count:0 mapcount:0 mapping:(null) index:0x0
page flags: 0x20000001000000(uncached)
Pid: 7956, comm: md5sum Not tainted 2.6.34-12-desktop #1
Call Trace:
 [<ffffffff810df851>] bad_page+0xb1/0x100
 [<ffffffff810dfa45>] prep_new_page+0x1a5/0x1c0
 [<ffffffff810dfe01>] get_page_from_freelist+0x3a1/0x640
 [<ffffffff810e01af>] __alloc_pages_nodemask+0x10f/0x6b0
...

In this particular case:

1) HPET returns 3ed00000 as memory region base, but it is not in
reserved ranges reported by the BIOS (excerpt):
 BIOS-e820: 0000000000100000 - 00000000af6cf000 (usable)
 BIOS-e820: 00000000af6cf000 - 00000000afdcf000 (reserved)

2) there is no IRQ resource reported by HPET method. On the other
hand, the Intel HPET specs (1.0a) says (3.2.5.1):
_CRS (
  // Report 1K of memory consumed by this Timer Block
  memory range consumed
  // Optional: only used if BIOS allocates Interrupts [1]
  IRQs consumed
)

[1] For case where Timer Block is configured to consume IRQ0/IRQ8 AND
Legacy 8254/Legacy RTC hardware still exists, the device objects
associated with 8254 & RTC devices should not report IRQ0/IRQ8 as
"consumed resources".

So in theory we should check whether if it is the case and use those
interrupts instead.

Anyway the address reported by the BIOS here is bogus, so non-presence
of IRQ doesn't mean the "optional" part in point 2).

Since I got no reply previously, fix this by simply unmapping the space
when IRQ is not found and memory region was mapped previously.  It would
be probably more safe to walk the resources again and unmap appropriately
depending on type.  But as we now use only ioremap for both 2 memory
resource types, it is not necessarily needed right now.

Addresses https://bugzilla.novell.com/show_bug.cgi?id=629908Reported-by: NOlaf Hering <olaf@aepfle.de>
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Acked-by: NClemens Ladisch <clemens@ladisch.de>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

a56d5318

mm: do_migrate_range: reduce list_empty() check · f3ab2636

由 Bob Liu 提交于 10月 26, 2010

Simple code for reducing list_empty(&source) check.
Signed-off-by: NBob Liu <lliubbo@gmail.com>
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: NWu Fengguang <fengguang.wu@intel.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

f3ab2636

mm: do_migrate_range: exit loop if not_managed is true · 809c4449

由 Bob Liu 提交于 10月 26, 2010

If not_managed is true all pages will be putback to lru, so break the loop
earlier to skip other pages isolate.
Signed-off-by: NBob Liu <lliubbo@gmail.com>
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: NWu Fengguang <fengguang.wu@intel.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

809c4449

mm: page_isolation: codeclean fix comment and rm unneeded val init · f6a3607e

由 Bob Liu 提交于 10月 26, 2010

__test_page_isolated_in_pageblock() returns 1 if all pages in the range
are isolated, so fix the comment.  Variable `pfn' will be initialised in
the following loop so remove it.
Signed-off-by: NBob Liu <lliubbo@gmail.com>
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

f6a3607e

mm: fix is_mem_section_removable() page_order BUG_ON check · 572438f9

由 KAMEZAWA Hiroyuki 提交于 10月 26, 2010

page_order() is called by memory hotplug's user interface to check the
section is removable or not.  (is_mem_section_removable())

It calls page_order() withoug holding zone->lock.
So, even if the caller does

	if (PageBuddy(page))
		ret = page_order(page) ...
The caller may hit BUG_ON().

For fixing this, there are 2 choices.
  1. add zone->lock.
  2. remove BUG_ON().

is_mem_section_removable() is used for some "advice" and doesn't need to
be 100% accurate.  This is_removable() can be called via user program..
We don't want to take this important lock for long by user's request.  So,
this patch removes BUG_ON().
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: NWu Fengguang <fengguang.wu@intel.com>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Acked-by: NMel Gorman <mel@csn.ul.ie>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

572438f9

mm/hugetlb.c: add missing spin_lock() to hugetlb_cow() · 44e2aa93

由 Dean Nelson 提交于 10月 26, 2010

Add missing spin_lock() of the page_table_lock before an error return in
hugetlb_cow(). Callers of hugtelb_cow() expect it to be held upon return.
Signed-off-by: NDean Nelson <dnelson@redhat.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

44e2aa93

mm: fix error reporting in move_pages() syscall · 70384dc6

由 Gleb Natapov 提交于 10月 26, 2010

The vma returned by find_vma does not necessarily include the target
address.  If this happens the code tries to follow a page outside of any
vma and returns ENOENT instead of EFAULT.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Acked-by: NChristoph Lameter <cl@linux-foundation.org>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

70384dc6

/proc/swaps: support polling · 66d7dd51

由 Kay Sievers 提交于 10月 26, 2010

System management wants to subscribe to changes in swap configuration.
Make /proc/swaps pollable like /proc/mounts.

[akpm@linux-foundation.org: document proc_poll_event]
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Acked-by: NGreg KH <greg@kroah.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

66d7dd51

mm: add vzalloc() and vzalloc_node() helpers · e1ca7788

由 Dave Young 提交于 10月 26, 2010

Add vzalloc() and vzalloc_node() to encapsulate the
vmalloc-then-memset-zero operation.

Use __GFP_ZERO to zero fill the allocated memory.
Signed-off-by: NDave Young <hidave.darkstar@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Acked-by: NGreg Ungerer <gerg@snapgear.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

e1ca7788

mm/memory_hotplug.c: make scan_lru_pages() static · 7bbc0905

由 Andrew Morton 提交于 10月 26, 2010

Reported-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

7bbc0905

fs/fs-writeback.c: restore lost comment · 74ce002d

由 Andrew Morton 提交于 10月 26, 2010

I had to go back to a 2.6.20 tree to work out why we're adding a
number-of-inodes into a number-of-pages count.  Restore the lost comment.

Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

74ce002d

mm: fix sparse warnings on GFP_ZONE_TABLE/BAD · 16b56cf4