This patch below does what Paul McKenney suggested in the previous thread.
Signed-off-by: Dave Jones <davej@redhat.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Paul Moore <paul@paul-moore.com> Cc: Eric Paris <eparis@parisplace.org> Cc: James Morris <jmorris@namei.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Corey Minyard [Thu, 15 Nov 2012 02:37:02 +0000 (13:37 +1100)]
CRIS: Fix I/O macros
The inb/outb macros for CRIS are broken from a number of points of view,
missing () around parameters and they have an unprotected if statement in
them. This was breaking the compile of IPMI on CRIS and thus I was being
annoyed by build regressions, so I fixed them.
Plus I don't think they would have worked at all, since the data values
were missing "&" and the outsl had a "3" instead of a "4" for the size.
From what I can tell, this stuff is not used at all, so this can't be any
more broken than it was before, anyway.
Mel Gorman [Thu, 15 Nov 2012 02:37:01 +0000 (13:37 +1100)]
mm: revert "mm: vmscan: scale number of pages reclaimed by reclaim/compaction based on failures"
Jiri Slaby reported the following:
(It's an effective revert of "mm: vmscan: scale number of pages
reclaimed by reclaim/compaction based on failures".) Given kswapd
had hours of runtime in ps/top output yesterday in the morning
and after the revert it's now 2 minutes in sum for the last 24h,
I would say, it's gone.
The intention of the patch in question was to compensate for the loss of
lumpy reclaim. Part of the reason lumpy reclaim worked is because it
aggressively reclaimed pages and this patch was meant to be a sane
compromise.
When compaction fails, it gets deferred and both compaction and
reclaim/compaction is deferred avoid excessive reclaim. However, since
commit c6543459 ("mm: remove __GFP_NO_KSWAPD"), kswapd is woken up each
time and continues reclaiming which was not taken into account when the
patch was developed.
Attempts to address the problem ended up just changing the shape of the
problem instead of fixing it. The release window gets closer and while a
THP allocation failing is not a major problem, kswapd chewing up a lot of
CPU is. This patch reverts "mm: vmscan: scale number of pages reclaimed
by reclaim/compaction based on failures" and will be revisited in the
future.
7b540d0646ce ("proc_map_files_readdir(): don't bother with grabbing
files") switched proc_map_files_readdir() to use @f_mode directly instead
of grabbing @file reference, but same time the test for @vm_file presence
was lost leading to nil dereference. The patch brings the test back.
The all proc_map_files feature is CONFIG_CHECKPOINT_RESTORE wrapped (which
is set to 'n' by default) so the bug doesn't affect regular kernels.
The regression is 3.7-rc1 only as far as I can tell.
[gorcunov@openvz.org: provided changelog] Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Jiang Liu [Thu, 15 Nov 2012 02:37:01 +0000 (13:37 +1100)]
mm: fix a regression with HIGHMEM
Changeset 7f1290f2f2 ("mm: fix-up zone present pages") tried to fix a
issue when calculating zone->present_pages, but it causes a regression to
32bit systems with HIGHMEM. With that changeset,
reset_zone_present_pages() resets all zone->present_pages to zero, and
fixup_zone_present_pages() is called to recalculate zone->present_pages
when the boot allocator frees core memory pages into the buddy allocator.
Because highmem pages are not freed by bootmem allocator, all highmem
zones' present_pages becomes zero.
Actually there's no need to recalculate present_pages for the highmem zone
because the bootmem allocator never allocates pages from it. So fix the
regression by skipping highmem in function reset_zone_present_pages() and
fixup_zone_present_pages().
Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Signed-off-by: Jianguo Wu <wujianguo@huawei.com> Reported-by: Maciej Rutecki <maciej.rutecki@gmail.com> Tested-by: Maciej Rutecki <maciej.rutecki@gmail.com> Tested-by: Chris Clayton <chris2553@googlemail.com> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Mel Gorman <mgorman@suse.de> Cc: Minchan Kim <minchan@kernel.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Hugh Dickins [Thu, 15 Nov 2012 02:37:00 +0000 (13:37 +1100)]
tmpfs: change final i_blocks BUG to WARNING
Under a particular load on one machine, I have hit shmem_evict_inode()'s
BUG_ON(inode->i_blocks), enough times to narrow it down to a particular
race between swapout and eviction.
It comes from the "if (freed > 0)" asymmetry in shmem_recalc_inode(), and
the lack of coherent locking between mapping's nrpages and shmem's swapped
count. There's a window in shmem_writepage(), between lowering nrpages in
shmem_delete_from_page_cache() and then raising swapped count, when the
freed count appears to be +1 when it should be 0, and then the asymmetry
stops it from being corrected with -1 before hitting the BUG.
One answer is coherent locking: using tree_lock throughout, without
info->lock; reasonable, but the raw_spin_lock in percpu_counter_add() on
used_blocks makes that messier than expected. Another answer may be a
further effort to eliminate the weird shmem_recalc_inode() altogether, but
previous attempts at that failed.
So far undecided, but for now change the BUG_ON to WARN_ON: in usual
circumstances it remains a useful consistency check.
Signed-off-by: Hugh Dickins <hughd@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Thanks to Johannes for pointing to truncation: free_swap_and_cache() only
does a trylock on the page, so the page lock we've held since before
confirming swap is not enough to protect against truncation.
What cleanup is needed in this case? Just delete_from_swap_cache(), which
takes care of the memcg uncharge.
Reported-by: Dave Jones <davej@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.com> Signed-off-by: Hugh Dickins <hughd@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Randy Dunlap [Thu, 15 Nov 2012 02:37:00 +0000 (13:37 +1100)]
rapidio: fix kernel-doc warnings
Fix rapidio kernel-doc warnings:
Warning(drivers/rapidio/rio.c:415): No description found for parameter 'local'
Warning(drivers/rapidio/rio.c:415): Excess function parameter 'lstart' description in 'rio_map_inb_region'
Warning(include/linux/rio.h:290): No description found for parameter 'switches'
Warning(include/linux/rio.h:290): No description found for parameter 'destid_table'
Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Matt Porter <mporter@kernel.crashing.org> Acked-by: Alexandre Bounine <alexandre.bounine@idt.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Ian Munsie [Thu, 8 Nov 2012 05:40:28 +0000 (16:40 +1100)]
powerpc: Disable relocation on exceptions when kexecing
Since we don't know if they new kernel we are kexecing into has been
built to support relocation on exceptions, we disable them before we
kexec.
We do NOT disable them if we are execing a kdump kernel, because we
want to change as little state as possible and it is likely that we are
execing ourselves and will be able to handle them anyway.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Ian Munsie [Thu, 8 Nov 2012 05:03:14 +0000 (16:03 +1100)]
powerpc: Enable relocation on during exceptions at boot
We currently do this synchronously at boot from setup_arch. On a large
system this could hypothetically take a little while to complete, so
currently we will give up if we are asked to wait for more than a second
in total.
If we actually start hitting that timeout in practice we can always move
this code into a kernel thread to take care of it in the background.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Ian Munsie [Thu, 8 Nov 2012 05:10:29 +0000 (16:10 +1100)]
powerpc: Move get_longbusy_msecs into hvcall.h and remove duplicate function
I am going to use this in the next patch, better to have this code in
one place rather than three.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Ian Munsie [Thu, 8 Nov 2012 04:57:04 +0000 (15:57 +1100)]
powerpc: Add wrappers to enable/disable relocation on exceptions
These wrappers hide the parameters that have to be passed to H_SET_MODE
to enable/disable relocation on during exceptions.
As noted in the comments, since these have partition wide scope, they
may take some time to complete and must be periodically retried until
H_SUCCESS is returned.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Ian Munsie [Tue, 6 Nov 2012 05:15:17 +0000 (16:15 +1100)]
powerpc: Add set_mode hcall
This new hcall in POWER8 is used to set various resource mode registers.
eg. it can set address translation mode on interrupt (note: partition wide
scope)
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Michael Neuling [Fri, 2 Nov 2012 05:41:58 +0000 (16:41 +1100)]
powerpc: Setup relocation on exceptions for bare metal systems
This turns on MMU on execptions via AIL field in the LPCR.
Signed-off-by: Matt Evans <matt@ozlabs.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Michael Neuling [Mon, 5 Nov 2012 03:40:18 +0000 (14:40 +1100)]
powerpc: Move initial mfspr LPCR out of __init_LPCR
We want to change what's initially set in the LPCR, so start by taking the move
from LPCR out of the function and into the caller.
Signed-off-by: Matt Evans <matt@ozlabs.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Michael Neuling [Fri, 2 Nov 2012 06:21:43 +0000 (17:21 +1100)]
powerpc: Add relocation on exception vector handlers
POWER8/v2.07 allows exceptions to be taken with the MMU still on.
A new set of exception vectors is added at 0xc000_0000_0000_4xxx. When the HW
takes us here, MSR IR/DR will be set already and we no longer need a costly
RFID to turn the MMU back on again.
The original 0x0 based exception vectors remain for when the HW can't leave the
MMU on. Examples of this are when we can't trust the current MMU mappings,
like when we are changing from guest to hypervisor (HV 0 -> 1) or when the MMU
was off already. In these cases the HW will take us to the original 0x0 based
exception vectors with the MMU off as before.
This uses the new macros added previously too implement these new execption
vectors at 0xc000_0000_0000_4xxx. We exit these exception vectors using
mflr/blr (rather than mtspr SSR0/RFID), since we don't need the costly MMU
switch anymore.
This moves the __end_interrupts marker down past these new 0x4000 vectors since
they will need to be copied down to 0x0 when the kernel is not at 0x0.
Signed-off-by: Matt Evans <matt@ozlabs.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Michael Neuling [Fri, 2 Nov 2012 06:21:28 +0000 (17:21 +1100)]
powerpc: Add new macros needed for relocation on exceptions
POWER8/v2.07 allows exceptions to be taken with the MMU still on.
A new set of exception vectors is added at 0xc000_0000_0000_4xxx. When the HW
takes us here, MSR IR/DR will be set already and we no longer need a costly
RFID to turn the MMU back on again.
The original 0x0 based exception vectors remain for when the HW can't leave the
MMU on. Examples of this are when we can't trust the current the MMU mappings,
like when we are changing from guest to hypervisor (HV 0 -> 1) or when the MMU
was off already. In these cases the HW will take us to the original 0x0 based
exception vectors with the MMU off as before.
The below macros are copies of the macros used at the 0x0 offset but modified
to handle the MMU being on. In these macros we use the link register to jump
to the secondary handlers rather than using RFID (RFID was also use to turn on
the MMU).
Signed-off-by: Matt Evans <matt@ozlabs.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Michael Neuling [Fri, 2 Nov 2012 06:16:01 +0000 (17:16 +1100)]
powerpc: Turn syscall handler into macros
This turns the syscall handler into macros as we are going to want to reuse
them again later.
Signed-off-by: Matt Evans <matt@ozlabs.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
If we build a kernel with CONFIG_RELOCATABLE=y CONFIG_CRASH_DUMP=n,
the kernel fails when we run at a non zero offset. It turns out
we were incorrectly wrapping some of the relocatable kernel code
with CONFIG_CRASH_DUMP.
Signed-off-by: Anton Blanchard <anton@samba.org> Cc: <stable@kernel.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Hugh Dickins [Thu, 15 Nov 2012 02:31:03 +0000 (13:31 +1100)]
memcg: fix hotplugged memory zone oops
When MEMCG is configured on (even when it's disabled by boot option), when
adding or removing a page to/from its lru list, the zone pointer used for
stats updates is nowadays taken from the struct lruvec. (On many
configurations, calculating zone from page is slower.)
But we have no code to update all the lruvecs (per zone, per memcg) when a
memory node is hotadded. Here's an extract from the oops which results
when running numactl to bind a program to a newly onlined node:
The natural solution might be to use a memcg callback whenever memory is
hotadded; but that solution has not been scoped out, and it happens that
we do have an easy location at which to update lruvec->zone. The lruvec
pointer is discovered either by mem_cgroup_zone_lruvec() or by
mem_cgroup_page_lruvec(), and both of those do know the right zone.
So check and set lruvec->zone in those; and remove the inadequate attempt
to set lruvec->zone from lruvec_init(), which is called before
NODE_DATA(node) has been allocated in such cases.
Ah, there was one exceptionr. For no particularly good reason,
mem_cgroup_force_empty_list() has its own code for deciding lruvec.
Change it to use the standard mem_cgroup_zone_lruvec() and
mem_cgroup_get_lru_size() too. In fact it was already safe against such
an oops (the lru lists in danger could only be empty), but we're better
proofed against future changes this way.
I've marked this for stable (3.6) since we introduced the problem in 3.5
(now closed to stable); but I have no idea if this is the only fix needed
to get memory hotadd working with memcg in 3.6, and received no answer
when I enquired twice before.
Reported-by: Tang Chen <tangchen@cn.fujitsu.com> Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Michal Hocko [Thu, 15 Nov 2012 02:31:03 +0000 (13:31 +1100)]
doc: describe memcg swappiness more precisely
since fe35004f (mm: avoid swapping out with swappiness==0) memcg reclaim
stopped swapping out anon pages completely when 0 value is used.
Although this is somehow expected it hasn't been done for a really long
time this way and so it is probably better to be explicit about the
effect. Moreover global reclaim swapps out even when swappiness is 0
to prevent from OOM killer.
The original issue (a wrong tasks get killed in a small group and memcg
swappiness=0) has been reported on top of our 3.0 based kernel (with fe35004f backported). I have tried to replicate it by the test case
mentioned https://lkml.org/lkml/2012/10/10/223.
As David correctly pointed out (https://lkml.org/lkml/2012/10/10/418) the
significant role played the fact that all the processes in the group have
CAP_SYS_ADMIN but oom_score_adj has the similar effect. Say there is 2G
of swap space which is 524288 pages. If you add CAP_SYS_ADMIN bonus then
you have -15728 score for the bias. This means that all tasks with less
than 60M get the minimum score and it is tasks ordering which determines
who gets killed as a result.
To summarize it. Users of small groups (relatively to the swap size) with
CAP_SYS_ADMIN tasks resp. oom_score_adj are affected the most others
might see an unexpected oom_badness calculation. Whether this is a
workload which is representative, I don't know but I think that it is
worth fixing and pushing to stable as well.
Signed-off-by: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Michal Hocko [Thu, 15 Nov 2012 02:31:02 +0000 (13:31 +1100)]
memcg: oom: fix totalpages calculation for memory.swappiness==0
oom_badness() takes a totalpages argument which says how many pages are
available and it uses it as a base for the score calculation. The value
is calculated by mem_cgroup_get_limit which considers both limit and
total_swap_pages (resp. memsw portion of it).
This is usually correct but since fe35004f ("mm: avoid swapping out with
swappiness==0") we do not swap when swappiness is 0 which means that we
cannot really use up all the totalpages pages. This in turn confuses oom
score calculation if the memcg limit is much smaller than the available
swap because the used memory (capped by the limit) is negligible comparing
to totalpages so the resulting score is too small if adj!=0 (typically
task with CAP_SYS_ADMIN or non zero oom_score_adj). A wrong process might
be selected as result.
The problem can be worked around by checking mem_cgroup_swappiness==0 and
not considering swap at all in such a case.
Signed-off-by: Michal Hocko <mhocko@suse.cz> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Rientjes [Thu, 15 Nov 2012 02:31:02 +0000 (13:31 +1100)]
mm: fix build warning for uninitialized value
do_wp_page() sets mmun_called if mmun_start and mmun_end were initialized
and, if so, may call mmu_notifier_invalidate_range_end() with these
values. This doesn't prevent gcc from emitting a build warning though:
mm/memory.c: In function `do_wp_page':
mm/memory.c:2530: warning: `mmun_start' may be used uninitialized in this function
mm/memory.c:2531: warning: `mmun_end' may be used uninitialized in this function
It's much easier to initialize the variables to impossible values and do a
simple comparison to determine if they were initialized to remove the bool
entirely.
Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Iterating over the vma->anon_vma_chain without anon_vma_lock may cause
NULL ptr deref in anon_vma_interval_tree_verify(), because the node in the
chain might have been removed.
Reported-by: Sasha Levin <sasha.levin@oracle.com> Cc: Bob Liu <lliubbo@gmail.com> Signed-off-by: Michel Lespinasse <walken@google.com> Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
projects / karo-tx-linux.git / log