zs_can_compact() has two race conditions in its core calculation:
unsigned long obj_wasted = zs_stat_get(class, OBJ_ALLOCATED) -
zs_stat_get(class, OBJ_USED);
1) classes are not locked, so the numbers of allocated and used
objects can change by the concurrent ops happening on other CPUs
2) shrinker invokes it from preemptible context
Depending on the circumstances, thus, OBJ_ALLOCATED can become
less than OBJ_USED, which can result in either very high or
negative `total_scan' value calculated later in do_shrink_slab().
do_shrink_slab() has some logic to prevent those cases:
vmscan: shrink_slab: zs_shrinker_scan+0x0/0x28 [zsmalloc] negative objects to delete nr=-62
vmscan: shrink_slab: zs_shrinker_scan+0x0/0x28 [zsmalloc] negative objects to delete nr=-62
vmscan: shrink_slab: zs_shrinker_scan+0x0/0x28 [zsmalloc] negative objects to delete nr=-64
vmscan: shrink_slab: zs_shrinker_scan+0x0/0x28 [zsmalloc] negative objects to delete nr=-62
vmscan: shrink_slab: zs_shrinker_scan+0x0/0x28 [zsmalloc] negative objects to delete nr=-62
vmscan: shrink_slab: zs_shrinker_scan+0x0/0x28 [zsmalloc] negative objects to delete nr=-62
However, due to the way `total_scan' is calculated, not every
shrinker->count_objects() overflow can be spotted and handled.
To demonstrate the latter, I added some debugging code to do_shrink_slab()
(x86_64) and the results were:
vmscan: OVERFLOW: shrinker->count_objects() == -1 [18446744073709551615]
vmscan: but total_scan > 0: 92679974445502
vmscan: resulting total_scan: 92679974445502
[..]
vmscan: OVERFLOW: shrinker->count_objects() == -1 [18446744073709551615]
vmscan: but total_scan > 0: 22634041808232578
vmscan: resulting total_scan: 22634041808232578
Even though shrinker->count_objects() has returned an overflowed value,
the resulting `total_scan' is positive, and, what is more worrisome, it
is insanely huge. This value is getting used later on in
shrinker->scan_objects() loop:
while (total_scan >= batch_size ||
total_scan >= freeable) {
unsigned long ret;
unsigned long nr_to_scan = min(batch_size, total_scan);
shrinkctl->nr_to_scan = nr_to_scan;
ret = shrinker->scan_objects(shrinker, shrinkctl);
if (ret == SHRINK_STOP)
break;
freed += ret;
count_vm_events(SLABS_SCANNED, nr_to_scan);
total_scan -= nr_to_scan;
cond_resched();
}
`total_scan >= batch_size' is true for a very-very long time and
'total_scan >= freeable' is also true for quite some time, because
`freeable < 0' and `total_scan' is large enough, for example,
22634041808232578. The only break condition, in the given scheme of
things, is shrinker->scan_objects() == SHRINK_STOP test, which is a
bit too weak to rely on, especially in heavy zsmalloc-usage scenarios.
To fix the issue, take a pool stat snapshot and use it instead of
racy zs_stat_get() calls.
Link: http://lkml.kernel.org/r/20160509140052.3389-1-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: <stable@vger.kernel.org> [4.3+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull writeback fix from Jens Axboe:
"Just a single fix for domain aware writeback, fixing a regression that
can cause balance_dirty_pages() to keep looping while not getting any
work done"
* 'for-linus' of git://git.kernel.dk/linux-block:
writeback: Fix performance regression in wb_over_bg_thresh()
Assume memory47 is the last online block left in node1. This will hang:
# echo offline > /sys/devices/system/node/node1/memory47/state
After a couple of minutes, the following pops up in dmesg:
INFO: task bash:957 blocked for more than 120 seconds.
Not tainted 4.6.0-rc6+ #6
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
bash D ffff8800b7adbaf8 0 957 951 0x00000000
Call Trace:
schedule+0x35/0x80
schedule_timeout+0x1ac/0x270
wait_for_completion+0xe1/0x120
kthread_stop+0x4f/0x110
kcompactd_stop+0x26/0x40
__offline_pages.constprop.28+0x7e6/0x840
offline_pages+0x11/0x20
memory_block_action+0x73/0x1d0
memory_subsys_offline+0x47/0x60
device_offline+0x86/0xb0
store_mem_state+0xda/0xf0
dev_attr_store+0x18/0x30
sysfs_kf_write+0x37/0x40
kernfs_fop_write+0x11d/0x170
__vfs_write+0x37/0x120
vfs_write+0xa9/0x1a0
SyS_write+0x55/0xc0
entry_SYSCALL_64_fastpath+0x1a/0xa4
kcompactd is waiting for kcompactd_max_order > 0 when it's woken up to
actually exit. Check kthread_should_stop() to break out of the wait.
Fixes: 698b1b306 ("mm, compaction: introduce kcompactd").
Reported-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Tested-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: David Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Instead of using "zswap" as the name for all zpools created, add an
atomic counter and use "zswap%x" with the counter number for each zpool
created, to provide a unique name for each new zpool.
As zsmalloc, one of the zpool implementations, requires/expects a unique
name for each pool created, zswap should provide a unique name. The
zsmalloc pool creation does not fail if a new pool with a conflicting
name is created, unless CONFIG_ZSMALLOC_STAT is enabled; in that case,
zsmalloc pool creation fails with -ENOMEM. Then zswap will be unable to
change its compressor parameter if its zpool is zsmalloc; it also will
be unable to change its zpool parameter back to zsmalloc, if it has any
existing old zpool using zsmalloc with page(s) in it. Attempts to
change the parameters will result in failure to create the zpool. This
changes zswap to provide a unique name for each zpool creation.
Fixes: f1c54846ee ("zswap: dynamic pool creation")
Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Dan Streetman <dan.streetman@canonical.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
/proc/sys/vm/stat_refresh warns nr_isolated_anon and nr_isolated_file go
increasingly negative under compaction: which would add delay when
should be none, or no delay when should delay. The bug in compaction
was due to a recent mmotm patch, but much older instance of the bug was
also noticed in isolate_migratepages_range() which is used for CMA and
gigantic hugepage allocations.
The bug is caused by putback_movable_pages() in an error path
decrementing the isolated counters without them being previously
incremented by acct_isolated(). Fix isolate_migratepages_range() by
removing the error-path putback, thus reaching acct_isolated() with
migratepages still isolated, and leaving putback to caller like most
other places do.
Fixes: edc2ca6124 ("mm, compaction: move pageblock checks up from isolate_migratepages_range()")
[vbabka@suse.cz: expanded the changelog]
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Khugepaged attempts to raise min_free_kbytes if its set too low.
However, on boot khugepaged sets min_free_kbytes first from
subsys_initcall(), and then the mm 'core' over-rides min_free_kbytes
after from init_per_zone_wmark_min(), via a module_init() call.
Khugepaged used to use a late_initcall() to set min_free_kbytes (such
that it occurred after the core initialization), however this was
removed when the initialization of min_free_kbytes was integrated into
the starting of the khugepaged thread.
The fix here is simply to invoke the core initialization using a
core_initcall() instead of module_init(), such that the previous
initialization ordering is restored. I didn't restore the
late_initcall() since start_stop_khugepaged() already sets
min_free_kbytes via set_recommended_min_free_kbytes().
This was noticed when we had a number of page allocation failures when
moving a workload to a kernel with this new initialization ordering. On
an 8GB system this restores min_free_kbytes back to 67584 from 11365
when CONFIG_TRANSPARENT_HUGEPAGE=y is set and either
CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS=y or
CONFIG_TRANSPARENT_HUGEPAGE_MADVISE=y.
Fixes: 79553da293 ("thp: cleanup khugepaged startup")
Signed-off-by: Jason Baron <jbaron@akamai.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
zap_pmd_range()'s CONFIG_DEBUG_VM !rwsem_is_locked(&mmap_sem) BUG() will
be invalid with huge pagecache, in whatever way it is implemented:
truncation of a hugely-mapped file to an unhugely-aligned size would
easily hit it.
(Although anon THP could in principle apply khugepaged to private file
mappings, which are not excluded by the MADV_HUGEPAGE restrictions, in
practice there's a vm_ops check which excludes them, so it never hits
this BUG() - there's no interface to "truncate" an anonymous mapping.)
We could complicate the test, to check i_mmap_rwsem also when there's a
vm_file; but my inclination was to make zap_pmd_range() more readable by
simply deleting this check. A search has shown no report of the issue
in the years since commit e0897d75f0 ("mm, thp: print useful
information when mmap_sem is unlocked in zap_pmd_range") expanded it
from VM_BUG_ON() - though I cannot point to what commit I would say then
fixed the issue.
But there are a couple of other patches now floating around, neither yet
in the tree: let's agree to retain the check as a VM_BUG_ON_VMA(), as
Matthew Wilcox has done; but subject to a vma_is_anonymous() check, as
Kirill Shutemov has done. And let's get this in, without waiting for
any particular huge pagecache implementation to reach the tree.
Matthew said "We can reproduce this BUG() in the current Linus tree with
DAX PMDs".
Signed-off-by: Hugh Dickins <hughd@google.com>
Tested-by: Matthew Wilcox <willy@linux.intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Yang Shi <yang.shi@linaro.org>
Cc: Ning Qu <quning@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 947e9762a8 ("writeback: update wb_over_bg_thresh() to use
wb_domain aware operations") unintentionally changed this function's
meaning from "are there more dirty pages than the background writeback
threshold" to "are there more dirty pages than the writeback threshold".
The background writeback threshold is typically half of the writeback
threshold, so this had the effect of raising the number of dirty pages
required to cause a writeback worker to perform background writeout.
This can cause a very severe performance regression when a BDI uses
BDI_CAP_STRICTLIMIT because balance_dirty_pages() and the writeback worker
can now disagree on whether writeback should be initiated.
For example, in a system having 1GB of RAM, a single spinning disk, and a
"pass-through" FUSE filesystem mounted over the disk, application code
mmapped a 128MB file on the disk and was randomly dirtying pages in that
mapping.
Because FUSE uses strictlimit and has a default max_ratio of only 1%, in
balance_dirty_pages, thresh is ~200, bg_thresh is ~100, and the
dirty_freerun_ceiling is the average of those, ~150. So, it pauses the
dirtying processes when we have 151 dirty pages and wakes up a background
writeback worker. But the worker tests the wrong threshold (200 instead of
100), so it does not initiate writeback and just returns.
Thus, balance_dirty_pages keeps looping, sleeping and then waking up the
worker who will do nothing. It remains stuck in this state until the few
dirty pages that we have finally expire and we write them back for that
reason. Then the whole process repeats, resulting in near-zero throughput
through the FUSE BDI.
The fix is to call the parameterized variant of wb_calc_thresh, so that the
worker will do writeback if the bg_thresh is exceeded which was the
behavior before the referenced commit.
Fixes: 947e9762a8 ("writeback: update wb_over_bg_thresh() to use wb_domain aware operations")
Signed-off-by: Howard Cochran <hcochran@kernelspring.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: <stable@vger.kernel.org> # v4.2+
Tested-by Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
get_hwpoison_page() must recheck relation between head and tail pages.
n-horiguchi said: without this recheck, the race causes kernel to pin an
irrelevant page, and finally makes kernel crash for refcount mismatch.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When kswapd goes to sleep it checks if the node is balanced and at first
it sleeps only for HZ/10 time, then rechecks if the node is still
balanced and nobody has woken it during the initial sleep. Only then it
goes fully sleep until an allocation slowpath wakes it up again.
For higher-order allocations, waking up kcompactd is done only before
the full sleep. This turns out to be an issue in case another
high-order allocation fails during the initial sleep. It will wake
kswapd up, however kswapd considers the zone balanced from the order-0
perspective, and will just quickly try to sleep again. So if there's a
longer stream of high-order allocations hitting the slowpath and waking
up kswapd, it might never actually wake up kcompactd, which may be
considered a regression from kswapd-based compaction. In the worst
case, it might be that a single allocation that cannot direct
reclaim/compact itself is waking kswapd in the retry loop and preventing
kcompactd from being woken up and unblocking it.
This patch makes sure kcompactd is woken up in such situations by simply
moving the wakeup before the short initial sleep. More efficient
solution would be to wake kcompactd immediately instead of kswapd if the
node is already order-0 balanced, but in that case we should also move
reset_isolation_suitable() call to kcompactd so it's not adding to the
allocator's latency. Since it's late in the 4.6 cycle, let's go with
the simpler change for now.
Fixes: accf62422b ("mm, kswapd: replace kswapd compaction with waking up kcompactd")
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: David Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, migration code increses num_poisoned_pages on *failed*
migration page as well as successfully migrated one at the trial of
memory-failure. It will make the stat wrong. As well, it marks the
page as PG_HWPoison even if the migration trial failed. It would mean
we cannot recover the corrupted page using memory-failure facility.
This patches fixes it.
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kyeongdon reported below error which is BUG_ON(!PageSwapCache(page)) in
page_swap_info. The reason is that page_endio in rw_page unlocks the
page if read I/O is completed so we need to hold a PG_lock again to
check PageSwapCache. Otherwise, the page can be removed from swapcache.
Kernel BUG at c00f9040 [verbose debug info unavailable]
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 4 PID: 13446 Comm: RenderThread Tainted: G W 3.10.84-g9f14aec-dirty #73
task: c3b73200 ti: dd192000 task.ti: dd192000
PC is at page_swap_info+0x10/0x2c
LR is at swap_slot_free_notify+0x18/0x6c
pc : [<c00f9040>] lr : [<c00f5560>] psr: 400f0113
sp : dd193d78 ip : c2deb1e4 fp : da015180
r10: 00000000 r9 : 000200da r8 : c120fe08
r7 : 00000000 r6 : 00000000 r5 : c249a6c0 r4 : = c249a6c0
r3 : 00000000 r2 : 40080009 r1 : 200f0113 r0 : = c249a6c0
..<snip> ..
Call Trace:
page_swap_info+0x10/0x2c
swap_slot_free_notify+0x18/0x6c
swap_readpage+0x90/0x11c
read_swap_cache_async+0x134/0x1ac
swapin_readahead+0x70/0xb0
handle_pte_fault+0x320/0x6fc
handle_mm_fault+0xc0/0xf0
do_page_fault+0x11c/0x36c
do_DataAbort+0x34/0x118
Fixes: 3f2b1a04f4 ("zram: revive swap_slot_free_notify")
Signed-off-by: Minchan Kim <minchan@kernel.org>
Tested-by: Kyeongdon Kim <kyeongdon.kim@lge.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We have been reclaimed highmem zone if buffer_heads is over limit but
commit 6b4f7799c6 ("mm: vmscan: invoke slab shrinkers from
shrink_zone()") changed the behavior so it doesn't reclaim highmem zone
although buffer_heads is over the limit. This patch restores the logic.
Fixes: 6b4f7799c6 ("mm: vmscan: invoke slab shrinkers from shrink_zone()")
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In gather_pte_stats() a THP pmd is cast into a pte, which is wrong
because the layouts may differ depending on the architecture. On s390
this will lead to inaccurate numa_maps accounting in /proc because of
misguided pte_present() and pte_dirty() checks on the fake pte.
On other architectures pte_present() and pte_dirty() may work by chance,
but there may be an issue with direct-access (dax) mappings w/o
underlying struct pages when HAVE_PTE_SPECIAL is set and THP is
available. In vm_normal_page() the fake pte will be checked with
pte_special() and because there is no "special" bit in a pmd, this will
always return false and the VM_PFNMAP | VM_MIXEDMAP checking will be
skipped. On dax mappings w/o struct pages, an invalid struct page
pointer would then be returned that can crash the kernel.
This patch fixes the numa_maps THP handling by introducing new "_pmd"
variants of the can_gather_numa_stats() and vm_normal_page() functions.
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org> [4.3+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hello,
So, this ended up a lot simpler than I originally expected. I tested
it lightly and it seems to work fine. Petr, can you please test these
two patches w/o the lru drain drop patch and see whether the problem
is gone?
Thanks.
------ 8< ------
If charge moving is used, memcg performs relabeling of the affected
pages from its ->attach callback which is called under both
cgroup_threadgroup_rwsem and thus can't create new kthreads. This is
fragile as various operations may depend on workqueues making forward
progress which relies on the ability to create new kthreads.
There's no reason to perform charge moving from ->attach which is deep
in the task migration path. Move it to ->post_attach which is called
after the actual migration is finished and cgroup_threadgroup_rwsem is
dropped.
* move_charge_struct->mm is added and ->can_attach is now responsible
for pinning and recording the target mm. mem_cgroup_clear_mc() is
updated accordingly. This also simplifies mem_cgroup_move_task().
* mem_cgroup_move_task() is now called from ->post_attach instead of
->attach.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@kernel.org>
Debugged-and-tested-by: Petr Mladek <pmladek@suse.com>
Reported-by: Cyril Hrubis <chrubis@suse.cz>
Reported-by: Johannes Weiner <hannes@cmpxchg.org>
Fixes: 1ed1328792 ("sched, cgroup: replace signal_struct->group_rwsem with a global percpu_rwsem")
Cc: <stable@vger.kernel.org> # 4.4+
Pull block fixes from Jens Axboe:
"A few fixes for the current series. This contains:
- Two fixes for NVMe:
One fixes a reset race that can be triggered by repeated
insert/removal of the module.
The other fixes an issue on some platforms, where we get probe
timeouts since legacy interrupts isn't working. This used not to
be a problem since we had the worker thread poll for completions,
but since that was killed off, it means those poor souls can't
successfully probe their NVMe device. Use a proper IRQ check and
probe (msi-x -> msi ->legacy), like most other drivers to work
around this. Both from Keith.
- A loop corruption issue with offset in iters, from Ming Lei.
- A fix for not having the partition stat per cpu ref count
initialized before sending out the KOBJ_ADD, which could cause user
space to access the counter prior to initialization. Also from
Ming Lei.
- A fix for using the wrong congestion state, from Kaixu Xia"
* 'for-linus' of git://git.kernel.dk/linux-block:
block: loop: fix filesystem corruption in case of aio/dio
NVMe: Always use MSI/MSI-x interrupts
NVMe: Fix reset/remove race
writeback: fix the wrong congested state variable definition
block: partition: initialize percpuref before sending out KOBJ_ADD
Pull mm gup cleanup from Ingo Molnar:
"This removes the ugly get-user-pages API hack, now that all upstream
code has been migrated to it"
("ugly" is putting it mildly. But it worked.. - Linus)
* 'mm-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
mm/gup: Remove the macro overload API migration helpers from the get_user*() APIs
The pkeys changes brought about a truly hideous set of macros in:
cde70140fe ("mm/gup: Overload get_user_pages() functions")
... which macros are (ab-)using the fact that __VA_ARGS__ can be used
to shift parameter positions in macro arguments without breaking the
build and so can be used to call separate C functions depending on
the number of arguments of the macro.
This allowed easy migration of these 3 GUP APIs, as both these variants
worked at the C level:
old:
ret = get_user_pages(current, current->mm, address, 1, 1, 0, &page, NULL);
new:
ret = get_user_pages(address, 1, 1, 0, &page, NULL);
... while we also generated a (functionally harmless but noticeable) build
time warning if the old API was used. As there are over 300 uses of these
APIs, this trick eased the migration of the API and avoided excessive
migration pain in linux-next.
Now, with its work done, get rid of all of that complication and ugliness:
3 files changed, 16 insertions(+), 140 deletions(-)
... where the linecount of the migration hack was further inflated by the
fact that there are NOMMU variants of these GUP APIs as well.
Much of the conversion was done in linux-next over the past couple of months,
and Linus recently removed all remaining old API uses from the upstream tree
in the following upstrea commit:
cb107161df ("Convert straggling drivers to new six-argument get_user_pages()")
There was one more old-API usage in mm/gup.c, in the CONFIG_HAVE_GENERIC_RCU_GUP
code path that ARM, ARM64 and PowerPC uses.
After this commit any old API usage will break the build.
[ Also fixed a PowerPC/HAVE_GENERIC_RCU_GUP warning reported by Stephen Rothwell. ]
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Merge PAGE_CACHE_SIZE removal patches from Kirill Shutemov:
"PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.
This promise never materialized. And unlikely will.
Let's stop pretending that pages in page cache are special. They are
not.
The first patch with most changes has been done with coccinelle. The
second is manual fixups on top.
The third patch removes macros definition"
[ I was planning to apply this just before rc2, but then I spaced out,
so here it is right _after_ rc2 instead.
As Kirill suggested as a possibility, I could have decided to only
merge the first two patches, and leave the old interfaces for
compatibility, but I'd rather get it all done and any out-of-tree
modules and patches can trivially do the converstion while still also
working with older kernels, so there is little reason to try to
maintain the redundant legacy model. - Linus ]
* PAGE_CACHE_SIZE-removal:
mm: drop PAGE_CACHE_* and page_cache_{get,release} definition
mm, fs: remove remaining PAGE_CACHE_* and page_cache_{get,release} usage
mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.
This promise never materialized. And unlikely will.
We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.
Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.
Let's stop pretending that pages in page cache are special. They are
not.
The changes are pretty straight-forward:
- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
- page_cache_get() -> get_page();
- page_cache_release() -> put_page();
This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.
The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.
There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.
virtual patch
@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT
@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE
@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK
@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)
@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)
@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sergey Senozhatsky
Linus Torvalds
Vlastimil Babka
Dan Streetman
Hugh Dickins
Jason Baron
Yang Shi
Howard Cochran
Konstantin Khlebnikov
Minchan Kim
Gerald Schaefer
Konstantin Khlebnikov
Kirill A. Shutemov
Tejun Heo
Ingo Molnar
Neil Zhang