06 Feb, 2016
12 commits
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We need to iterate over split_queue, not local empty list to get
anything split from the shrinker.Fixes: e3ae19535c66 ("thp: limit number of object to scan on deferred_split_scan()")
Signed-off-by: Kirill A. Shutemov
Cc: Andrea Arcangeli
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Sequence vma_lock_anon_vma() - vma_unlock_anon_vma() isn't safe if
anon_vma appeared between lock and unlock. We have to check anon_vma
first or call anon_vma_prepare() to be sure that it's here. There are
only few users of these legacy helpers. Let's get rid of them.This patch fixes anon_vma lock imbalance in validate_mm(). Write lock
isn't required here, read lock is enough.And reorders expand_downwards/expand_upwards: security_mmap_addr() and
wrapping-around check don't have to be under anon vma lock.Link: https://lkml.kernel.org/r/CACT4Y+Y908EjM2z=706dv4rV6dWtxTLK9nFg9_7DhRMLppBo2g@mail.gmail.com
Signed-off-by: Konstantin Khlebnikov
Reported-by: Dmitry Vyukov
Acked-by: Kirill A. Shutemov
Cc: Andrea Arcangeli
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Commit 944d9fec8d7a ("hugetlb: add support for gigantic page allocation
at runtime") has added the runtime gigantic page allocation via
alloc_contig_range(), making this support available only when CONFIG_CMA
is enabled. Because it doesn't depend on MIGRATE_CMA pageblocks and the
associated infrastructure, it is possible with few simple adjustments to
require only CONFIG_MEMORY_ISOLATION instead of full CONFIG_CMA.After this patch, alloc_contig_range() and related functions are
available and used for gigantic pages with just CONFIG_MEMORY_ISOLATION
enabled. Note CONFIG_CMA selects CONFIG_MEMORY_ISOLATION. This allows
supporting runtime gigantic pages without the CMA-specific checks in
page allocator fastpaths.Signed-off-by: Vlastimil Babka
Cc: Luiz Capitulino
Cc: Kirill A. Shutemov
Cc: Zhang Yanfei
Cc: Yasuaki Ishimatsu
Cc: Joonsoo Kim
Cc: Naoya Horiguchi
Cc: Mel Gorman
Cc: Davidlohr Bueso
Cc: Hillf Danton
Cc: Mike Kravetz
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Attempting to preallocate 1G gigantic huge pages at boot time with
"hugepagesz=1G hugepages=1" on the kernel command line will prevent
booting with the following:kernel BUG at mm/hugetlb.c:1218!
When mapcount accounting was reworked, the setting of
compound_mapcount_ptr in prep_compound_gigantic_page was overlooked. As
a result, the validation of mapcount in free_huge_page fails.The "BUG_ON" checks in free_huge_page were also changed to
"VM_BUG_ON_PAGE" to assist with debugging.Fixes: 53f9263baba69 ("mm: rework mapcount accounting to enable 4k mapping of THPs")
Signed-off-by: Mike Kravetz
Signed-off-by: Naoya Horiguchi
Acked-by: Kirill A. Shutemov
Acked-by: David Rientjes
Tested-by: Vlastimil Babka
Cc: "Aneesh Kumar K.V"
Cc: Jerome Marchand
Cc: Michal Hocko
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Calling isolate_lru_page() is wrong and shouldn't happen, but it not
nessesary fatal: the page just will not be isolated if it's not on LRU.Let's downgrade the VM_BUG_ON_PAGE() to WARN_RATELIMIT().
Signed-off-by: Kirill A. Shutemov
Cc: Dmitry Vyukov
Cc: Vlastimil Babka
Cc: David Rientjes
Cc: Naoya Horiguchi
Acked-by: Michal Hocko
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Maybe I miss some point, but I don't see a reason why we try to queue
pages from non migratable VMAs.This testcase steps on VM_BUG_ON_PAGE() in isolate_lru_page():
#include
#include
#include
#include
#include#define SIZE 0x2000
int foo;
int main()
{
int fd;
char *p;
unsigned long mask = 2;fd = open("/dev/sg0", O_RDWR);
p = mmap(NULL, SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
/* Faultin pages */
foo = p[0] + p[0x1000];
mbind(p, SIZE, MPOL_BIND, &mask, 4, MPOL_MF_MOVE | MPOL_MF_STRICT);
return 0;
}The only case when we can queue pages from such VMA is MPOL_MF_STRICT
plus MPOL_MF_MOVE or MPOL_MF_MOVE_ALL for VMA which has pages on LRU,
but gfp mask is not sutable for migaration (see mapping_gfp_mask() check
in vma_migratable()). That's looks like a bug to me.Let's filter out non-migratable vma at start of queue_pages_test_walk()
and go to queue_pages_pte_range() only if MPOL_MF_MOVE or
MPOL_MF_MOVE_ALL flag is set.Signed-off-by: Kirill A. Shutemov
Signed-off-by: Dmitry Vyukov
Cc: Vlastimil Babka
Cc: David Rientjes
Cc: Naoya Horiguchi
Cc: Michal Hocko
Cc: Johannes Weiner
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Jan Stancek has reported that system occasionally hanging after "oom01"
testcase from LTP triggers OOM. Guessing from a result that there is a
kworker thread doing memory allocation and the values between "Node 0
Normal free:" and "Node 0 Normal:" differs when hanging, vmstat is not
up-to-date for some reason.According to commit 373ccbe59270 ("mm, vmstat: allow WQ concurrency to
discover memory reclaim doesn't make any progress"), it meant to force
the kworker thread to take a short sleep, but it by error used
schedule_timeout(1). We missed that schedule_timeout() in state
TASK_RUNNING doesn't do anything.Fix it by using schedule_timeout_uninterruptible(1) which forces the
kworker thread to take a short sleep in order to make sure that vmstat
is up-to-date.Fixes: 373ccbe59270 ("mm, vmstat: allow WQ concurrency to discover memory reclaim doesn't make any progress")
Signed-off-by: Tetsuo Handa
Reported-by: Jan Stancek
Acked-by: Michal Hocko
Cc: Tejun Heo
Cc: Cristopher Lameter
Cc: Joonsoo Kim
Cc: Arkadiusz Miskiewicz
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Commit 0eb77e988032 ("vmstat: make vmstat_updater deferrable again and
shut down on idle") made vmstat_shepherd deferrable. vmstat_update
itself is still useing standard timer which might interrupt idle task.
This is possible because "mm, vmstat: make quiet_vmstat lighter" removed
cancel_delayed_work from the quiet_vmstat.Change vmstat_work to use DEFERRABLE_WORK to prevent from pointless
wakeups from the idle context.Acked-by: Christoph Lameter
Signed-off-by: Michal Hocko
Cc: Mike Galbraith
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Mike has reported a considerable overhead of refresh_cpu_vm_stats from
the idle entry during pipe test:12.89% [kernel] [k] refresh_cpu_vm_stats.isra.12
4.75% [kernel] [k] __schedule
4.70% [kernel] [k] mutex_unlock
3.14% [kernel] [k] __switch_toThis is caused by commit 0eb77e988032 ("vmstat: make vmstat_updater
deferrable again and shut down on idle") which has placed quiet_vmstat
into cpu_idle_loop. The main reason here seems to be that the idle
entry has to get over all zones and perform atomic operations for each
vmstat entry even though there might be no per cpu diffs. This is a
pointless overhead for _each_ idle entry.Make sure that quiet_vmstat is as light as possible.
First of all it doesn't make any sense to do any local sync if the
current cpu is already set in oncpu_stat_off because vmstat_update puts
itself there only if there is nothing to do.Then we can check need_update which should be a cheap way to check for
potential per-cpu diffs and only then do refresh_cpu_vm_stats.The original patch also did cancel_delayed_work which we are not doing
here. There are two reasons for that. Firstly cancel_delayed_work from
idle context will blow up on RT kernels (reported by Mike):CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.5.0-rt3 #7
Hardware name: MEDION MS-7848/MS-7848, BIOS M7848W08.20C 09/23/2013
Call Trace:
dump_stack+0x49/0x67
___might_sleep+0xf5/0x180
rt_spin_lock+0x20/0x50
try_to_grab_pending+0x69/0x240
cancel_delayed_work+0x26/0xe0
quiet_vmstat+0x75/0xa0
cpu_idle_loop+0x38/0x3e0
cpu_startup_entry+0x13/0x20
start_secondary+0x114/0x140And secondly, even on !RT kernels it might add some non trivial overhead
which is not necessary. Even if the vmstat worker wakes up and preempts
idle then it will be most likely a single shot noop because the stats
were already synced and so it would end up on the oncpu_stat_off anyway.
We just need to teach both vmstat_shepherd and vmstat_update to stop
scheduling the worker if there is nothing to do.[mgalbraith@suse.de: cancel pending work of the cpu_stat_off CPU]
Signed-off-by: Michal Hocko
Reported-by: Mike Galbraith
Acked-by: Christoph Lameter
Signed-off-by: Mike Galbraith
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The description mentions kswapd threads, while the deferred struct page
initialization is actually done by one-off "pgdatinitX" threads.Fix the description so that potentially users are not confused about
pgdatinit threads using CPU after boot instead of kswapd.Signed-off-by: Vlastimil Babka
Acked-by: Mel Gorman
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
At the moment memblock_phys_mem_size() is marked as __init, and so is
discarded after boot. This is different from most of the memblock
functions which are marked __init_memblock, and are only discarded after
boot if memory hotplug is not configured.To allow for upcoming code which will need memblock_phys_mem_size() in
the hotplug path, change it from __init to __init_memblock.Signed-off-by: David Gibson
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The mmap_sem for reading in validate_mm called from expand_stack is not
enough to prevent the argumented rbtree rb_subtree_gap information to
change from under us because expand_stack may be running from other
threads concurrently which will hold the mmap_sem for reading too.The argumented rbtree is updated with vma_gap_update under the
page_table_lock so use it in browse_rb() too to avoid false positives.Signed-off-by: Andrea Arcangeli
Reported-by: Dmitry Vyukov
Tested-by: Dmitry Vyukov
Cc: Konstantin Khlebnikov
Cc: Oleg Nesterov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
04 Feb, 2016
10 commits
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Merge fixes from Andrew Morton:
"18 fixes"[ The 18 fixes turned into 17 commits, because one of the fixes was a
fix for another patch in the series that I just folded in by editing
the patch manually - hopefully correctly - Linus ]* emailed patches from Andrew Morton :
mm: fix memory leak in copy_huge_pmd()
drivers/hwspinlock: fix race between radix tree insertion and lookup
radix-tree: fix race in gang lookup
mm/vmpressure.c: fix subtree pressure detection
mm: polish virtual memory accounting
mm: warn about VmData over RLIMIT_DATA
Documentation: cgroup-v2: add memory.stat::sock description
mm: memcontrol: drop superfluous entry in the per-memcg stats array
drivers/scsi/sg.c: mark VMA as VM_IO to prevent migration
proc: revert /proc//maps [stack:TID] annotation
numa: fix /proc//numa_maps for hugetlbfs on s390
MAINTAINERS: update Seth email
ocfs2/cluster: fix memory leak in o2hb_region_release
lib/test-string_helpers.c: fix and improve string_get_size() tests
thp: limit number of object to scan on deferred_split_scan()
thp: change deferred_split_count() to return number of THP in queue
thp: make split_queue per-node -
Trinity is now hitting the WARN_ON_ONCE we added in v3.15 commit
cda540ace6a1 ("mm: get_user_pages(write,force) refuse to COW in shared
areas"). The warning has served its purpose, nobody was harmed by that
change, so just remove the warning to generate less noise from Trinity.Which reminds me of the comment I wrongly left behind with that commit
(but was spotted at the time by Kirill), which has since moved into a
separate function, and become even more obscure: delete it.Reported-by: Dave Jones
Suggested-by: Kirill A. Shutemov
Signed-off-by: Hugh Dickins
Signed-off-by: Linus Torvalds -
We allocate a pgtable but do not attach it to anything if the PMD is in
a DAX VMA, causing it to leak.We certainly try to not free pgtables associated with the huge zero page
if the zero page is in a DAX VMA, so I think this is the right solution.
This needs to be properly audited.Signed-off-by: Matthew Wilcox
Cc: Dan Williams
Acked-by: Kirill A. Shutemov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
When vmpressure is called for the entire subtree under pressure we
mistakenly use vmpressure->scanned instead of vmpressure->tree_scanned
when checking if vmpressure work is to be scheduled. This results in
suppressing all vmpressure events in the legacy cgroup hierarchy. Fix it.Fixes: 8e8ae645249b ("mm: memcontrol: hook up vmpressure to socket pressure")
Signed-off-by: Vladimir Davydov
Acked-by: Johannes Weiner
Acked-by: Michal Hocko
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
* add VM_STACK as alias for VM_GROWSUP/DOWN depending on architecture
* always account VMAs with flag VM_STACK as stack (as it was before)
* cleanup classifying helpers
* update comments and documentationSigned-off-by: Konstantin Khlebnikov
Tested-by: Sudip Mukherjee
Cc: Cyrill Gorcunov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch provides a way of working around a slight regression
introduced by commit 84638335900f ("mm: rework virtual memory
accounting").Before that commit RLIMIT_DATA have control only over size of the brk
region. But that change have caused problems with all existing versions
of valgrind, because it set RLIMIT_DATA to zero.This patch fixes rlimit check (limit actually in bytes, not pages) and
by default turns it into warning which prints at first VmData misuse:"mmap: top (795): VmData 516096 exceed data ulimit 512000. Will be forbidden soon."
Behavior is controlled by boot param ignore_rlimit_data=y/n and by sysfs
/sys/module/kernel/parameters/ignore_rlimit_data. For now it set to "y".[akpm@linux-foundation.org: tweak kernel-parameters.txt text[
Signed-off-by: Konstantin Khlebnikov
Link: http://lkml.kernel.org/r/20151228211015.GL2194@uranus
Reported-by: Christian Borntraeger
Cc: Cyrill Gorcunov
Cc: Linus Torvalds
Cc: Vegard Nossum
Cc: Peter Zijlstra
Cc: Vladimir Davydov
Cc: Andy Lutomirski
Cc: Quentin Casasnovas
Cc: Kees Cook
Cc: Willy Tarreau
Cc: Pavel Emelyanov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Commit b76437579d13 ("procfs: mark thread stack correctly in
proc//maps") added [stack:TID] annotation to /proc//maps.Finding the task of a stack VMA requires walking the entire thread list,
turning this into quadratic behavior: a thousand threads means a
thousand stacks, so the rendering of /proc//maps needs to look at a
million combinations.The cost is not in proportion to the usefulness as described in the
patch.Drop the [stack:TID] annotation to make /proc//maps (and
/proc//numa_maps) usable again for higher thread counts.The [stack] annotation inside /proc//task//maps is retained, as
identifying the stack VMA there is an O(1) operation.Siddesh said:
"The end users needed a way to identify thread stacks programmatically and
there wasn't a way to do that. I'm afraid I no longer remember (or have
access to the resources that would aid my memory since I changed
employers) the details of their requirement. However, I did do this on my
own time because I thought it was an interesting project for me and nobody
really gave any feedback then as to its utility, so as far as I am
concerned you could roll back the main thread maps information since the
information is available in the thread-specific files"Signed-off-by: Johannes Weiner
Cc: "Kirill A. Shutemov"
Cc: Siddhesh Poyarekar
Cc: Shaohua Li
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
If we have a lot of pages in queue to be split, deferred_split_scan()
can spend unreasonable amount of time under spinlock with disabled
interrupts.Let's cap number of pages to split on scan by sc->nr_to_scan.
Signed-off-by: Kirill A. Shutemov
Reported-by: Andrea Arcangeli
Reviewed-by: Andrea Arcangeli
Cc: Hugh Dickins
Cc: Dave Hansen
Cc: Mel Gorman
Cc: Rik van Riel
Cc: Vlastimil Babka
Cc: "Aneesh Kumar K.V"
Cc: Johannes Weiner
Cc: Michal Hocko
Cc: Jerome Marchand
Cc: Sasha Levin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
I've got meaning of shrinker::count_objects() wrong: it should return
number of potentially freeable objects, which is not necessary correlate
with freeable memory.Returning 256 per THP in queue is not reasonable:
shrinker::scan_objects() never called with nr_to_scan > 128 in my setup.Let's return 1 per THP and correct scan_object accordingly.
Signed-off-by: Kirill A. Shutemov
Reviewed-by: Andrea Arcangeli
Cc: Hugh Dickins
Cc: Dave Hansen
Cc: Mel Gorman
Cc: Rik van Riel
Cc: Vlastimil Babka
Cc: "Aneesh Kumar K.V"
Cc: Johannes Weiner
Cc: Michal Hocko
Cc: Jerome Marchand
Cc: Sasha Levin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Andrea Arcangeli suggested to make split queue per-node to improve
scalability. Let's do it.Signed-off-by: Kirill A. Shutemov
Suggested-by: Andrea Arcangeli
Reviewed-by: Andrea Arcangeli
Cc: Hugh Dickins
Cc: Dave Hansen
Cc: Mel Gorman
Cc: Rik van Riel
Cc: Vlastimil Babka
Cc: "Aneesh Kumar K.V"
Cc: Johannes Weiner
Cc: Michal Hocko
Cc: Jerome Marchand
Cc: Sasha Levin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
02 Feb, 2016
1 commit
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Pull libnvdimm fixes from Dan Williams:
"1/ Fixes to the libnvdimm 'pfn' device that establishes a reserved
area for storing a struct page array.2/ Fixes for dax operations on a raw block device to prevent pagecache
collisions with dax mappings.3/ A fix for pfn_t usage in vm_insert_mixed that lead to a null
pointer de-reference.These have received build success notification from the kbuild robot
across 153 configs and pass the latest ndctl tests"* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
phys_to_pfn_t: use phys_addr_t
mm: fix pfn_t to page conversion in vm_insert_mixed
block: use DAX for partition table reads
block: revert runtime dax control of the raw block device
fs, block: force direct-I/O for dax-enabled block devices
devm_memremap_pages: fix vmem_altmap lifetime + alignment handling
libnvdimm, pfn: fix restoring memmap location
libnvdimm: fix mode determination for e820 devices
01 Feb, 2016
1 commit
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pfn_t_to_page() honors the flags in the pfn_t value to determine if a
pfn is backed by a page. However, vm_insert_mixed() was originally
written to use pfn_valid() to make this determination. To restore the
old/correct behavior, ignore the pfn_t flags in the !pfn_t_devmap() case
and fallback to trusting pfn_valid().Fixes: 01c8f1c44b83 ("mm, dax, gpu: convert vm_insert_mixed to pfn_t")
Cc: Dave Hansen
Cc: David Airlie
Reported-by: Tomi Valkeinen
Tested-by: Tomi Valkeinen
Signed-off-by: Dan Williams
30 Jan, 2016
1 commit
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Pull cleancache cleanups from Konrad Rzeszutek Wilk:
"Simple cleanups"* 'stable/for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/mm:
include/linux/cleancache.h: Clean up code
cleancache: constify cleancache_ops structure
27 Jan, 2016
1 commit
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The cleancache_ops structure is never modified, so declare it as const.
Done with the help of Coccinelle.
Signed-off-by: Julia Lawall
Signed-off-by: Konrad Rzeszutek Wilk
25 Jan, 2016
1 commit
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If we detect that there is nothing to do just set the flag and do not
check if it was already set before. Races really do not matter. If the
flag is set by any code then the shepherd will start dealing with the
situation and reenable the vmstat workers when necessary again.Since commit 0eb77e988032 ("vmstat: make vmstat_updater deferrable again
and shut down on idle") quiet_vmstat might update cpu_stat_off and mark
a particular cpu to be handled by vmstat_shepherd. This might trigger a
VM_BUG_ON in vmstat_update because the work item might have been
sleeping during the idle period and see the cpu_stat_off updated after
the wake up. The VM_BUG_ON is therefore misleading and no more
appropriate. Moreover it doesn't really suite any protection from real
bugs because vmstat_shepherd will simply reschedule the vmstat_work
anytime it sees a particular cpu set or vmstat_update would do the same
from the worker context directly. Even when the two would race the
result wouldn't be incorrect as the counters update is fully idempotent.Reported-by: Sasha Levin
Signed-off-by: Christoph Lameter
Acked-by: Michal Hocko
Cc: Johannes Weiner
Cc: Tetsuo Handa
Cc: Andrew Morton
Signed-off-by: Linus Torvalds
24 Jan, 2016
1 commit
-
Pull final vfs updates from Al Viro:
- The ->i_mutex wrappers (with small prereq in lustre)
- a fix for too early freeing of symlink bodies on shmem (they need to
be RCU-delayed) (-stable fodder)- followup to dedupe stuff merged this cycle
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
vfs: abort dedupe loop if fatal signals are pending
make sure that freeing shmem fast symlinks is RCU-delayed
wrappers for ->i_mutex access
lustre: remove unused declaration
23 Jan, 2016
6 commits
-
There are many locations that do
if (memory_was_allocated_by_vmalloc)
vfree(ptr);
else
kfree(ptr);but kvfree() can handle both kmalloc()ed memory and vmalloc()ed memory
using is_vmalloc_addr(). Unless callers have special reasons, we can
replace this branch with kvfree(). Please check and reply if you found
problems.Signed-off-by: Tetsuo Handa
Acked-by: Michal Hocko
Acked-by: Jan Kara
Acked-by: Russell King
Reviewed-by: Andreas Dilger
Acked-by: "Rafael J. Wysocki"
Acked-by: David Rientjes
Cc: "Luck, Tony"
Cc: Oleg Drokin
Cc: Boris Petkov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
To properly handle fsync/msync in an efficient way DAX needs to track
dirty pages so it is able to flush them durably to media on demand.The tracking of dirty pages is done via the radix tree in struct
address_space. This radix tree is already used by the page writeback
infrastructure for tracking dirty pages associated with an open file,
and it already has support for exceptional (non struct page*) entries.
We build upon these features to add exceptional entries to the radix
tree for DAX dirty PMD or PTE pages at fault time.[dan.j.williams@intel.com: fix dax_pmd_dbg build warning]
Signed-off-by: Ross Zwisler
Cc: "H. Peter Anvin"
Cc: "J. Bruce Fields"
Cc: "Theodore Ts'o"
Cc: Alexander Viro
Cc: Andreas Dilger
Cc: Dave Chinner
Cc: Ingo Molnar
Cc: Jan Kara
Cc: Jeff Layton
Cc: Matthew Wilcox
Cc: Thomas Gleixner
Cc: Matthew Wilcox
Cc: Dave Hansen
Signed-off-by: Dan Williams
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add find_get_entries_tag() to the family of functions that include
find_get_entries(), find_get_pages() and find_get_pages_tag(). This is
needed for DAX dirty page handling because we need a list of both page
offsets and radix tree entries ('indices' and 'entries' in this
function) that are marked with the PAGECACHE_TAG_TOWRITE tag.Signed-off-by: Ross Zwisler
Reviewed-by: Jan Kara
Cc: "H. Peter Anvin"
Cc: "J. Bruce Fields"
Cc: "Theodore Ts'o"
Cc: Alexander Viro
Cc: Andreas Dilger
Cc: Dave Chinner
Cc: Ingo Molnar
Cc: Jeff Layton
Cc: Matthew Wilcox
Cc: Thomas Gleixner
Cc: Dan Williams
Cc: Matthew Wilcox
Cc: Dave Hansen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add support for tracking dirty DAX entries in the struct address_space
radix tree. This tree is already used for dirty page writeback, and it
already supports the use of exceptional (non struct page*) entries.In order to properly track dirty DAX pages we will insert new
exceptional entries into the radix tree that represent dirty DAX PTE or
PMD pages. These exceptional entries will also contain the writeback
addresses for the PTE or PMD faults that we can use at fsync/msync time.There are currently two types of exceptional entries (shmem and shadow)
that can be placed into the radix tree, and this adds a third. We rely
on the fact that only one type of exceptional entry can be found in a
given radix tree based on its usage. This happens for free with DAX vs
shmem but we explicitly prevent shadow entries from being added to radix
trees for DAX mappings.The only shadow entries that would be generated for DAX radix trees
would be to track zero page mappings that were created for holes. These
pages would receive minimal benefit from having shadow entries, and the
choice to have only one type of exceptional entry in a given radix tree
makes the logic simpler both in clear_exceptional_entry() and in the
rest of DAX.Signed-off-by: Ross Zwisler
Cc: "H. Peter Anvin"
Cc: "J. Bruce Fields"
Cc: "Theodore Ts'o"
Cc: Alexander Viro
Cc: Andreas Dilger
Cc: Dave Chinner
Cc: Ingo Molnar
Cc: Jan Kara
Cc: Jeff Layton
Cc: Matthew Wilcox
Cc: Thomas Gleixner
Cc: Dan Williams
Cc: Matthew Wilcox
Cc: Dave Hansen
Cc: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Cc: stable@vger.kernel.org # v4.2+
Signed-off-by: Al Viro -
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.Signed-off-by: Al Viro
22 Jan, 2016
3 commits
-
This crash is caused by NULL pointer deference, in page_to_pfn() marco,
when page == NULL :Unable to handle kernel NULL pointer dereference at virtual address 00000000
Internal error: Oops: 94000006 [#1] SMP
Modules linked in:
CPU: 1 PID: 26 Comm: khugepaged Tainted: G W 4.3.0-rc6-next-20151022ajb-00001-g32f3386-dirty #3
PC is at khugepaged+0x378/0x1af8
LR is at khugepaged+0x418/0x1af8
Process khugepaged (pid: 26, stack limit = 0xffffffc079638020)
Call trace:
khugepaged+0x378/0x1af8
kthread+0xdc/0xf4
ret_from_fork+0xc/0x40
Code: 35001700 f0002c60 aa0703e3 f9009fa0 (f94000e0)
---[ end trace 637503d8e28ae69e ]---
Kernel panic - not syncing: Fatal exception
CPU2: stopping
CPU: 2 PID: 0 Comm: swapper/2 Tainted: G D W 4.3.0-rc6-next-20151022ajb-00001-g32f3386-dirty #3
Hardware name: linux,dummy-virt (DT)[akpm@linux-foundation.org: fix fat-fingered merge resolution]
Signed-off-by: yalin wang
Acked-by: Vlastimil Babka
Acked-by: Kirill A. Shutemov
Acked-by: David Rientjes
Cc: Cyrill Gorcunov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Tetsuo Handa reported underflow of NR_MLOCK on munlock.
Testcase:
#include
#include
#include#define BASE ((void *)0x400000000000)
#define SIZE (1UL << 21)int main(int argc, char *argv[])
{
void *addr;system("grep Mlocked /proc/meminfo");
addr = mmap(BASE, SIZE, PROT_READ | PROT_WRITE,
MAP_ANONYMOUS | MAP_PRIVATE | MAP_LOCKED | MAP_FIXED,
-1, 0);
if (addr == MAP_FAILED)
printf("mmap() failed\n"), exit(1);
munmap(addr, SIZE);
system("grep Mlocked /proc/meminfo");
return 0;
}It happens on munlock_vma_page() due to unfortunate choice of nr_pages
data type:__mod_zone_page_state(zone, NR_MLOCK, -nr_pages);
For unsigned int nr_pages, implicitly casted to long in
__mod_zone_page_state(), it becomes something around UINT_MAX.munlock_vma_page() usually called for THP as small pages go though
pagevec.Let's make nr_pages signed int.
Similar fixes in 6cdb18ad98a4 ("mm/vmstat: fix overflow in
mod_zone_page_state()") used `long' type, but `int' here is OK for a
count of the number of sub-pages in a huge page.Fixes: ff6a6da60b89 ("mm: accelerate munlock() treatment of THP pages")
Signed-off-by: Kirill A. Shutemov
Reported-by: Tetsuo Handa
Tested-by: Tetsuo Handa
Cc: Michel Lespinasse
Acked-by: Michal Hocko
Cc: [4.4+]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
After THP refcounting rework we have only two possible return values
from pmd_trans_huge_lock(): success and failure. Return-by-pointer for
ptl doesn't make much sense in this case.Let's convert pmd_trans_huge_lock() to return ptl on success and NULL on
failure.Signed-off-by: Kirill A. Shutemov
Suggested-by: Linus Torvalds
Cc: Minchan Kim
Acked-by: Michal Hocko
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
21 Jan, 2016
3 commits
-
Provide statistics on how much of a cgroup's memory footprint is made up
of socket buffers from network connections owned by the group.Signed-off-by: Johannes Weiner
Cc: Michal Hocko
Cc: Vladimir Davydov
Cc: Tejun Heo
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Provide a cgroup2 memory.stat that provides statistics on LRU memory
and fault event counters. More consumers and breakdowns will follow.Signed-off-by: Johannes Weiner
Acked-by: Vladimir Davydov
Cc: Michal Hocko
Cc: Tejun Heo
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Changing page->mem_cgroup of a live page is tricky and fragile. In
particular, the memcg writeback code relies on that mapping being stable
and users of mem_cgroup_replace_page() not overlapping with dirtyable
inodes.Page cache replacement doesn't have to do that, though. Instead of being
clever and transferring the charge from the old page to the new,
force-charge the new page and leave the old page alone. A temporary
overcharge won't matter in practice, and the old page is going to be freed
shortly after this anyway. And this is not performance critical.Signed-off-by: Johannes Weiner
Cc: Michal Hocko
Cc: Vladimir Davydov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds