With the goal of allowing tmem backends (zcache, ramster, Xen tmem) to
be built/loaded as modules rather than built-in and enabled by a boot
parameter, this patch provides "lazy initialization", allowing backends
to register to cleancache even after filesystems were mounted. Calls to
init_fs and init_shared_fs are remembered as fake poolids but no real
tmem_pools created. On backend registration the fake poolids are mapped
to real poolids and respective tmem_pools.
Signed-off-by: Stefan Hengelein <ilendir@googlemail.com>
Signed-off-by: Florian Schmaus <fschmaus@gmail.com>
Signed-off-by: Andor Daam <andor.daam@googlemail.com>
Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
[v1: Minor fixes: used #define for some values and bools]
[v2: Removed CLEANCACHE_HAS_LAZY_INIT]
[v3: Added more comments, added a lock for [shared_|]fs_poolid_map]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Frontswap initialization routine depends on swap_lock, which want to be
atomic about frontswap's first appearance. IOW, frontswap is not present
and will fail all calls OR frontswap is fully functional but if new
swap_info_struct isn't registered by enable_swap_info, swap subsystem
doesn't start I/O so there is no race between init procedure and page I/O
working on frontswap.
So let's remove unnecessary swap_lock dependency.
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
[v1: Rebased on my branch, reworked to work with backends loading late]
[v2: Added a check for !map]
[v3: Made the invalidate path follow the init path]
[v4: Address comments by Wanpeng Li <liwanp@linux.vnet.ibm.com>]
Signed-off-by: Konrad Rzeszutek Wilk <konrad@darnok.org>
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Andor Daam <andor.daam@googlemail.com>
Cc: Florian Schmaus <fschmaus@gmail.com>
Cc: Stefan Hengelein <ilendir@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With the goal of allowing tmem backends (zcache, ramster, Xen tmem) to
be built/loaded as modules rather than built-in and enabled by a boot
parameter, this patch provides "lazy initialization", allowing backends
to register to frontswap even after swapon was run. Before a backend
registers all calls to init are recorded and the creation of tmem_pools
delayed until a backend registers or until a frontswap store is
attempted.
Signed-off-by: Stefan Hengelein <ilendir@googlemail.com>
Signed-off-by: Florian Schmaus <fschmaus@gmail.com>
Signed-off-by: Andor Daam <andor.daam@googlemail.com>
Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
[v1: Fixes per Seth Jennings suggestions]
[v2: Removed FRONTSWAP_HAS_.. ]
[v3: Fix up per Bob Liu <lliubbo@gmail.com> recommendations]
[v4: Fix up per Andrew's comments]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge second batch of fixes from Andrew Morton:
- various misc bits
- some printk updates
- a new "SRAM" driver.
- MAINTAINERS updates
- the backlight driver queue
- checkpatch updates
- a few init/ changes
- a huge number of drivers/rtc changes
- fatfs updates
- some lib/idr.c work
- some renaming of the random driver interfaces
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (285 commits)
net: rename random32 to prandom
net/core: remove duplicate statements by do-while loop
net/core: rename random32() to prandom_u32()
net/netfilter: rename random32() to prandom_u32()
net/sched: rename random32() to prandom_u32()
net/sunrpc: rename random32() to prandom_u32()
scsi: rename random32() to prandom_u32()
lguest: rename random32() to prandom_u32()
uwb: rename random32() to prandom_u32()
video/uvesafb: rename random32() to prandom_u32()
mmc: rename random32() to prandom_u32()
drbd: rename random32() to prandom_u32()
kernel/: rename random32() to prandom_u32()
mm/: rename random32() to prandom_u32()
lib/: rename random32() to prandom_u32()
x86: rename random32() to prandom_u32()
x86: pageattr-test: remove srandom32 call
uuid: use prandom_bytes()
raid6test: use prandom_bytes()
sctp: convert sctp_assoc_set_id() to use idr_alloc_cyclic()
...
Pull cgroup updates from Tejun Heo:
- Fixes and a lot of cleanups. Locking cleanup is finally complete.
cgroup_mutex is no longer exposed to individual controlelrs which
used to cause nasty deadlock issues. Li fixed and cleaned up quite a
bit including long standing ones like racy cgroup_path().
- device cgroup now supports proper hierarchy thanks to Aristeu.
- perf_event cgroup now supports proper hierarchy.
- A new mount option "__DEVEL__sane_behavior" is added. As indicated
by the name, this option is to be used for development only at this
point and generates a warning message when used. Unfortunately,
cgroup interface currently has too many brekages and inconsistencies
to implement a consistent and unified hierarchy on top. The new flag
is used to collect the behavior changes which are necessary to
implement consistent unified hierarchy. It's likely that this flag
won't be used verbatim when it becomes ready but will be enabled
implicitly along with unified hierarchy.
The option currently disables some of broken behaviors in cgroup core
and also .use_hierarchy switch in memcg (will be routed through -mm),
which can be used to make very unusual hierarchy where nesting is
partially honored. It will also be used to implement hierarchy
support for blk-throttle which would be impossible otherwise without
introducing a full separate set of control knobs.
This is essentially versioning of interface which isn't very nice but
at this point I can't see any other options which would allow keeping
the interface the same while moving towards hierarchy behavior which
is at least somewhat sane. The planned unified hierarchy is likely
to require some level of adaptation from userland anyway, so I think
it'd be best to take the chance and update the interface such that
it's supportable in the long term.
Maintaining the existing interface does complicate cgroup core but
shouldn't put too much strain on individual controllers and I think
it'd be manageable for the foreseeable future. Maybe we'll be able
to drop it in a decade.
Fix up conflicts (including a semantic one adding a new #include to ppc
that was uncovered by header the file changes) as per Tejun.
* 'for-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (45 commits)
cpuset: fix compile warning when CONFIG_SMP=n
cpuset: fix cpu hotplug vs rebuild_sched_domains() race
cpuset: use rebuild_sched_domains() in cpuset_hotplug_workfn()
cgroup: restore the call to eventfd->poll()
cgroup: fix use-after-free when umounting cgroupfs
cgroup: fix broken file xattrs
devcg: remove parent_cgroup.
memcg: force use_hierarchy if sane_behavior
cgroup: remove cgrp->top_cgroup
cgroup: introduce sane_behavior mount option
move cgroupfs_root to include/linux/cgroup.h
cgroup: convert cgroupfs_root flag bits to masks and add CGRP_ prefix
cgroup: make cgroup_path() not print double slashes
Revert "cgroup: remove bind() method from cgroup_subsys."
perf: make perf_event cgroup hierarchical
cgroup: implement cgroup_is_descendant()
cgroup: make sure parent won't be destroyed before its children
cgroup: remove bind() method from cgroup_subsys.
devcg: remove broken_hierarchy tag
cgroup: remove cgroup_lock_is_held()
...
The memcg is not referenced, so it can be destroyed at anytime right
after we exit rcu read section, so it's not safe to access it.
To fix this, we call css_tryget() to get a reference while we're still
in rcu read section.
This also removes a bogus comment above __memcg_create_cache_enqueue().
Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: Glauber Costa <glommer@parallels.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.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>
There are times when HIGHMEM is enabled, but we don't prefer
CONFIG_BOUNCE to be enabled. CONFIG_BOUNCE can reduce the block device
throughput, and this is not ideal for machines where we don't gain much
by enabling it. So provide an option to deselect CONFIG_BOUNCE. The
observation was made while measuring eMMC throughput using iozone on an
ARM device with 1GB RAM.
Signed-off-by: Vinayak Menon <vinayakm.list@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
PFN_PHYS() is a phys_addr_t, which can be u32 or u64.
Fix the build warning when phys_addr_t is u32.
mm/memory_hotplug.c: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 2 has type 'unsigned int' [-Wformat]: => 1685:3
mm/memory_hotplug.c: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'unsigned int' [-Wformat]: => 1685:3
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As pointed out by Andrew Morton, the swap-over-NFS writeback is not
setting PageWriteback before it is queued for direct IO. While swap
pages do not participate in BDI or process dirty accounting and the IO
is synchronous, the writeback bit is still required and not setting it
in this case was an oversight. swapoff depends on the page writeback to
synchronoise all pending writes on a swap page before it is reused.
Swapcache freeing and reuse depend on checking the PageWriteback under
lock to ensure the page is safe to reuse.
Direct IO handlers and the direct IO handler for NFS do not deal with
PageWriteback as they are synchronous writes. In the case of NFS, it
schedules pages (or a page in the case of swap) for IO and then waits
synchronously for IO to complete in nfs_direct_write(). It is
recognised that this is a slowdown from normal swap handling which is
asynchronous and uses a completion handler. Shoving PageWriteback
handling down into direct IO handlers looks like a bad fit to handle the
swap case although it may have to be dealt with some day if swap is
converted to use direct IO in general and bmap is finally done away
with. At that point it will be necessary to refit asynchronous direct
IO with completion handlers onto the swap subsystem.
As swapcache currently depends on PageWriteback to protect against
races, this patch sets PageWriteback under the page lock before queueing
it for direct IO. It is cleared when the direct IO handler returns. IO
errors are treated similarly to the direct-to-bio case except PageError
is not set as in the case of swap-over-NFS, it is likely to be a
transient error.
It was asked what prevents such a page being reclaimed in parallel.
With this patch applied, such a page will now be skipped (most of the
time) or blocked until the writeback completes. Reclaim checks
PageWriteback under the page lock before calling try_to_free_swap and
the page lock should prevent the page being requeued for IO before it is
freed.
This and Jerome's related patch should considered for -stable as far
back as 3.6 when swap-over-NFS was introduced.
[akpm@linux-foundation.org: use pr_err_ratelimited()]
[akpm@linux-foundation.org: remove hopefully-unneeded cast in printk]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org> [3.6+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since commit 62c230bc17 ("mm: add support for a filesystem to activate
swap files and use direct_IO for writing swap pages"), swap_writepage()
calls direct_IO on swap files. However, in that case the page isn't
redirtied if I/O fails, and is therefore handled afterwards as if it has
been successfully written to the swap file, leading to memory corruption
when the page is eventually swapped back in.
This patch sets the page dirty when direct_IO() fails. It fixes a
memory corruption that happened while using swap-over-NFS.
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org> [3.6+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A memcg may livelock when oom if the process that grabs the hierarchy's
oom lock is never the first process with PF_EXITING set in the memcg's
task iteration.
The oom killer, both global and memcg, will defer if it finds an
eligible process that is in the process of exiting and it is not being
ptraced. The idea is to allow it to exit without using memory reserves
before needlessly killing another process.
This normally works fine except in the memcg case with a large number of
threads attached to the oom memcg. In this case, the memcg oom killer
only gets called for the process that grabs the hierarchy's oom lock;
all others end up blocked on the memcg's oom waitqueue. Thus, if the
process that grabs the hierarchy's oom lock is never the first
PF_EXITING process in the memcg's task iteration, the oom killer is
constantly deferred without anything making progress.
The fix is to give PF_EXITING processes access to memory reserves so
that we've marked them as oom killed without any iteration. This allows
__mem_cgroup_try_charge() to succeed so that the process may exit. This
makes the memcg oom killer exemption for TIF_MEMDIE tasks, now
immediately granted for processes with pending SIGKILLs and those in the
exit path, to be equivalent to what is done for the global oom killer.
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Current implementation of huge zero page uses pfn value 0 to indicate
that the page hasn't allocated yet. It assumes that buddy page
allocator can't return page with pfn == 0.
Let's rework the code to store 'struct page *' of huge zero page, not
its pfn. This way we can avoid the weak assumption.
[akpm@linux-foundation.org: fix sparse warning]
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Minchan Kim <minchan@kernel.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are two convenient ways to report errors to userspace
1) retun error to original syscall for example write(2)
2) mark mapping with error flag and return it on later fsync(2)
Second one is broken if (mapping->nrpages == 0) This is real-life
situation because after error pages are likey to be truncated or
invalidated.
We have to return an error regardless to number of pages in the mapping.
#Original testcase: git@github.com:dmonakhov/xfstests.git
MOUNT_OPTIONS="-b1024"
./check shared/305
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In page reclaim, huge page is split. split_huge_page() adds tail pages
to LRU list. Since we are reclaiming a huge page, it's better we
reclaim all subpages of the huge page instead of just the head page.
This patch adds split tail pages to shrink page list so the tail pages
can be reclaimed soon.
Before this patch, run a swap workload:
thp_fault_alloc 3492
thp_fault_fallback 608
thp_collapse_alloc 6
thp_collapse_alloc_failed 0
thp_split 916
With this patch:
thp_fault_alloc 4085
thp_fault_fallback 16
thp_collapse_alloc 90
thp_collapse_alloc_failed 0
thp_split 1272
fallback allocation is reduced a lot.
[akpm@linux-foundation.org: fix CONFIG_SWAP=n build]
Signed-off-by: Shaohua Li <shli@fusionio.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.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>
