23 Sep, 2009
3 commits
-
Move various magic-number definitions into magic.h.
Signed-off-by: Nick Black
Acked-by: Pekka Enberg
Cc: Al Viro
Cc: "David S. Miller"
Cc: Casey Schaufler
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
When syslog is not possible, at the same time there's no serial/net
console available, it will be hard to read the printk messages. For
example oops/panic/warning messages in shutdown phase.Add a printk delay feature, we can make each printk message delay some
milliseconds.Setting the delay by proc/sysctl interface: /proc/sys/kernel/printk_delay
The value range from 0 - 10000, default value is 0
[akpm@linux-foundation.org: fix a few things]
Signed-off-by: Dave Young
Acked-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
of the form
include/net/inet_sock.h:208: warning: ISO C90 forbids mixed declarations and code
Cc: Johannes Berg
Acked-by: Vegard Nossum
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
22 Sep, 2009
37 commits
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* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/vegard/kmemcheck:
kmemcheck: add missing braces to do-while in kmemcheck_annotate_bitfield
kmemcheck: update documentation
kmemcheck: depend on HAVE_ARCH_KMEMCHECK
kmemcheck: remove useless check
kmemcheck: remove duplicated #include -
* 'for-2.6.32' of git://linux-nfs.org/~bfields/linux: (68 commits)
nfsd4: nfsv4 clients should cross mountpoints
nfsd: revise 4.1 status documentation
sunrpc/cache: avoid variable over-loading in cache_defer_req
sunrpc/cache: use list_del_init for the list_head entries in cache_deferred_req
nfsd: return success for non-NFS4 nfs4_state_start
nfsd41: Refactor create_client()
nfsd41: modify nfsd4.1 backchannel to use new xprt class
nfsd41: Backchannel: Implement cb_recall over NFSv4.1
nfsd41: Backchannel: cb_sequence callback
nfsd41: Backchannel: Setup sequence information
nfsd41: Backchannel: Server backchannel RPC wait queue
nfsd41: Backchannel: Add sequence arguments to callback RPC arguments
nfsd41: Backchannel: callback infrastructure
nfsd4: use common rpc_cred for all callbacks
nfsd4: allow nfs4 state startup to fail
SUNRPC: Defer the auth_gss upcall when the RPC call is asynchronous
nfsd4: fix null dereference creating nfsv4 callback client
nfsd4: fix whitespace in NFSPROC4_CLNT_CB_NULL definition
nfsd41: sunrpc: add new xprt class for nfsv4.1 backchannel
sunrpc/cache: simplify cache_fresh_locked and cache_fresh_unlocked.
... -
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (34 commits)
trivial: fix typo in aic7xxx comment
trivial: fix comment typo in drivers/ata/pata_hpt37x.c
trivial: typo in kernel-parameters.txt
trivial: fix typo in tracing documentation
trivial: add __init/__exit macros in drivers/gpio/bt8xxgpio.c
trivial: add __init macro/ fix of __exit macro location in ipmi_poweroff.c
trivial: remove unnecessary semicolons
trivial: Fix duplicated word "options" in comment
trivial: kbuild: remove extraneous blank line after declaration of usage()
trivial: improve help text for mm debug config options
trivial: doc: hpfall: accept disk device to unload as argument
trivial: doc: hpfall: reduce risk that hpfall can do harm
trivial: SubmittingPatches: Fix reference to renumbered step
trivial: fix typos "man[ae]g?ment" -> "management"
trivial: media/video/cx88: add __init/__exit macros to cx88 drivers
trivial: fix typo in CONFIG_DEBUG_FS in gcov doc
trivial: fix missing printk space in amd_k7_smp_check
trivial: fix typo s/ketymap/keymap/ in comment
trivial: fix typo "to to" in multiple files
trivial: fix typos in comments s/DGBU/DBGU/
... -
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
HID: Remove duplicate Kconfig entry
HID: consolidate connect and disconnect into core code
HID: fix non-atomic allocation in hid_input_report -
The shutdown method is used by the winbond cir driver to setup the
hardware for wake-from-S5.Signed-off-by: Bjorn Helgaas
Signed-off-by: David Härdeman
Cc: Dmitry Torokhov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This offers a way for platforms to define flags and thresholds for the
free-fall/wakeup functions of the lis302d chips.More registers needed to be seperated as they are specific to the
Signed-off-by: Daniel Mack
Acked-by: Pavel Machek
Cc: Eric Piel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Bit 0x80 in CTRL_REG3 is an ACTIVE_LOW rather than an ACTIVE_HIGH
function, I got that wrong during my last change.Signed-off-by: Daniel Mack
Acked-by: Pavel Machek
Cc: Eric Piel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
FLEX_ARRAY_INIT(element_size, total_nr_elements) cannot determine if
either parameter is valid, so flex arrays which are statically allocated
with this interface can easily become corrupted or reference beyond its
allocated memory.This removes FLEX_ARRAY_INIT() as a struct flex_array initializer since no
initializer may perform the required checking. Instead, the array is now
defined with a new interface:DEFINE_FLEX_ARRAY(name, element_size, total_nr_elements)
This may be prefixed with `static' for file scope.
This interface includes compile-time checking of the parameters to ensure
they are valid. Since the validity of both element_size and
total_nr_elements depend on FLEX_ARRAY_BASE_SIZE and FLEX_ARRAY_PART_SIZE,
the kernel build will fail if either of these predefined values changes
such that the array parameters are no longer valid.Since BUILD_BUG_ON() requires compile time constants, several of the
static inline functions that were once local to lib/flex_array.c had to be
moved to include/linux/flex_array.h.Signed-off-by: David Rientjes
Acked-by: Dave Hansen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add a new function to the flex_array API:
int flex_array_shrink(struct flex_array *fa)
This function will free all unused second-level pages. Since elements are
now poisoned if they are not allocated with __GFP_ZERO, it's possible to
identify parts that consist solely of unused elements.flex_array_shrink() returns the number of pages freed.
Signed-off-by: David Rientjes
Cc: Dave Hansen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Newly initialized flex_array's and/or flex_array_part's are now poisoned
with a new poison value, FLEX_ARRAY_FREE. It's value is similar to
POISON_FREE used in the various slab allocators, but is different to
distinguish between flex array's poisoned kmem and slab allocator poisoned
kmem.This will allow us to identify flex_array_part's that only contain free
elements (and free them with an addition to the flex_array API). This
could also be extended in the future to identify `get' uses on elements
that have not been `put'.If __GFP_ZERO is passed for a part's gfp mask, the poisoning is avoided.
These elements are considered to be in-use since they have been
initialized.Signed-off-by: David Rientjes
Cc: Dave Hansen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add a new function to the flex_array API:
int flex_array_clear(struct flex_array *fa,
unsigned int element_nr)This function will zero the element at element_nr in the flex_array.
Although this is equivalent to using flex_array_put() and passing a
pointer to zero'd memory, flex_array_clear() does not require such a
pointer to memory that would most likely need to be allocated on the
caller's stack which could be significantly large depending on
element_size.Signed-off-by: David Rientjes
Cc: Dave Hansen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fix the menu idle governor which balances power savings, energy efficiency
and performance impact.The reason for a reworked governor is that there have been serious
performance issues reported with the existing code on Nehalem server
systems.To show this I'm sure Andrew wants to see benchmark results:
(benchmark is "fio", "no cstates" is using "idle=poll")no cstates current linux new algorithm
1 disk 107 Mb/s 85 Mb/s 105 Mb/s
2 disks 215 Mb/s 123 Mb/s 209 Mb/s
12 disks 590 Mb/s 320 Mb/s 585 Mb/sIn various power benchmark measurements, no degredation was found by our
measurement&diagnostics team. Obviously a small percentage more power was
used in the "fio" benchmark, due to the much higher performance.While it would be a novel idea to describe the new algorithm in this
commit message, I cheaped out and described it in comments in the code
instead.[changes since first post: spelling fixes from akpm, review feedback,
folded menu-tng into menu.c]Signed-off-by: Arjan van de Ven
Cc: Venkatesh Pallipadi
Cc: Len Brown
Cc: Ingo Molnar
Cc: Peter Zijlstra
Cc: Yanmin Zhang
Acked-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Anyone who wants to do copy to/from user from a kernel thread, needs
use_mm (like what fs/aio has). Move that into mm/, to make reusing and
exporting easier down the line, and make aio use it. Next intended user,
besides aio, will be vhost-net.Acked-by: Andrea Arcangeli
Signed-off-by: Michael S. Tsirkin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add a flag for mmap that will be used to request a huge page region that
will look like anonymous memory to userspace. This is accomplished by
using a file on the internal vfsmount. MAP_HUGETLB is a modifier of
MAP_ANONYMOUS and so must be specified with it. The region will behave
the same as a MAP_ANONYMOUS region using small pages.[akpm@linux-foundation.org: fix arch definitions of MAP_HUGETLB]
Signed-off-by: Eric B Munson
Acked-by: David Rientjes
Cc: Mel Gorman
Cc: Adam Litke
Cc: David Gibson
Cc: Lee Schermerhorn
Cc: Nick Piggin
Cc: Hugh Dickins
Cc: Arnd Bergmann
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add a flag for mmap that will be used to request a huge page region that
will look like anonymous memory to user space. This is accomplished by
using a file on the internal vfsmount. MAP_HUGETLB is a modifier of
MAP_ANONYMOUS and so must be specified with it. The region will behave
the same as a MAP_ANONYMOUS region using small pages.The patch also adds the MAP_STACK flag, which was previously defined only
on some architectures but not on others. Since MAP_STACK is meant to be a
hint only, architectures can define it without assigning a specific
meaning to it.Signed-off-by: Arnd Bergmann
Cc: Eric B Munson
Cc: Hugh Dickins
Cc: David Rientjes
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patchset adds a flag to mmap that allows the user to request that an
anonymous mapping be backed with huge pages. This mapping will borrow
functionality from the huge page shm code to create a file on the kernel
internal mount and use it to approximate an anonymous mapping. The
MAP_HUGETLB flag is a modifier to MAP_ANONYMOUS and will not work without
both flags being preset.A new flag is necessary because there is no other way to hook into huge
pages without creating a file on a hugetlbfs mount which wouldn't be
MAP_ANONYMOUS.To userspace, this mapping will behave just like an anonymous mapping
because the file is not accessible outside of the kernel.This patchset is meant to simplify the programming model. Presently there
is a large chunk of boiler platecode, contained in libhugetlbfs, required
to create private, hugepage backed mappings. This patch set would allow
use of hugepages without linking to libhugetlbfs or having hugetblfs
mounted.Unification of the VM code would provide these same benefits, but it has
been resisted each time that it has been suggested for several reasons: it
would break PAGE_SIZE assumptions across the kernel, it makes page-table
abstractions really expensive, and it does not provide any benefit on
architectures that do not support huge pages, incurring fast path
penalties without providing any benefit on these architectures.This patch:
There are two means of creating mappings backed by huge pages:
1. mmap() a file created on hugetlbfs
2. Use shm which creates a file on an internal mount which essentially
maps it MAP_SHAREDThe internal mount is only used for shared mappings but there is very
little that stops it being used for private mappings. This patch extends
hugetlbfs_file_setup() to deal with the creation of files that will be
mapped MAP_PRIVATE on the internal hugetlbfs mount. This extended API is
used in a subsequent patch to implement the MAP_HUGETLB mmap() flag.Signed-off-by: Eric Munson
Acked-by: David Rientjes
Cc: Mel Gorman
Cc: Adam Litke
Cc: David Gibson
Cc: Lee Schermerhorn
Cc: Nick Piggin
Cc: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
CONFIG_SHMEM off gives you (ramfs masquerading as) tmpfs, even when
CONFIG_TMPFS is off: that's a little anomalous, and I'd intended to make
more sense of it by removing CONFIG_TMPFS altogether, always enabling its
code when CONFIG_SHMEM; but so many defconfigs have CONFIG_SHMEM on
CONFIG_TMPFS off that we'd better leave that as is.But there is no point in asking for CONFIG_TMPFS if CONFIG_SHMEM is off:
make TMPFS depend on SHMEM, which also prevents TMPFS_POSIX_ACL
shmem_acl.o being pointlessly built into the kernel when SHMEM is off.And a selfish change, to prevent the world from being rebuilt when I
switch between CONFIG_SHMEM on and off: the only CONFIG_SHMEM in the
header files is mm.h shmem_lock() - give that a shmem.c stub instead.Signed-off-by: Hugh Dickins
Acked-by: Matt Mackall
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
__get_user_pages() has been taking its own GUP flags, then processing
them into FOLL flags for follow_page(). Though oddly named, the FOLL
flags are more widely used, so pass them to __get_user_pages() now.
Sorry, VM flags, VM_FAULT flags and FAULT_FLAGs are still distinct.(The patch to __get_user_pages() looks peculiar, with both gup_flags
and foll_flags: the gup_flags remain constant; but as before there's
an exceptional case, out of scope of the patch, in which foll_flags
per page have FOLL_WRITE masked off.)Signed-off-by: Hugh Dickins
Cc: Rik van Riel
Cc: KAMEZAWA Hiroyuki
Cc: KOSAKI Motohiro
Cc: Nick Piggin
Cc: Mel Gorman
Cc: Minchan Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
follow_hugetlb_page() shouldn't be guessing about the coredump case
either: pass the foll_flags down to it, instead of just the write bit.Remove that obscure huge_zeropage_ok() test. The decision is easy,
though unlike the non-huge case - here vm_ops->fault is always set.
But we know that a fault would serve up zeroes, unless there's
already a hugetlbfs pagecache page to back the range.(Alternatively, since hugetlb pages aren't swapped out under pressure,
you could save more dump space by arguing that a page not yet faulted
into this process cannot be relevant to the dump; but that would be
more surprising.)Signed-off-by: Hugh Dickins
Acked-by: Rik van Riel
Cc: KAMEZAWA Hiroyuki
Cc: KOSAKI Motohiro
Cc: Nick Piggin
Cc: Mel Gorman
Cc: Minchan Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The "FOLL_ANON optimization" and its use_zero_page() test have caused
confusion and bugs: why does it test VM_SHARED? for the very good but
unsatisfying reason that VMware crashed without. As we look to maybe
reinstating anonymous use of the ZERO_PAGE, we need to sort this out.Easily done: it's silly for __get_user_pages() and follow_page() to
be guessing whether it's safe to assume that they're being used for
a coredump (which can take a shortcut snapshot where other uses must
handle a fault) - just tell them with GUP_FLAGS_DUMP and FOLL_DUMP.get_dump_page() doesn't even want a ZERO_PAGE: an error suits fine.
Signed-off-by: Hugh Dickins
Acked-by: Rik van Riel
Acked-by: Mel Gorman
Reviewed-by: Minchan Kim
Cc: KAMEZAWA Hiroyuki
Cc: KOSAKI Motohiro
Cc: Nick Piggin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
In preparation for the next patch, add a simple get_dump_page(addr)
interface for the CONFIG_ELF_CORE dumpers to use, instead of calling
get_user_pages() directly. They're not interested in errors: they
just want to use holes as much as possible, to save space and make
sure that the data is aligned where the headers said it would be.Oh, and don't use that horrid DUMP_SEEK(off) macro!
Signed-off-by: Hugh Dickins
Acked-by: Rik van Riel
Cc: KAMEZAWA Hiroyuki
Cc: KOSAKI Motohiro
Cc: Nick Piggin
Cc: Mel Gorman
Cc: Minchan Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The following two patches remove searching in the page allocator fast-path
by maintaining multiple free-lists in the per-cpu structure. At the time
the search was introduced, increasing the per-cpu structures would waste a
lot of memory as per-cpu structures were statically allocated at
compile-time. This is no longer the case.The patches are as follows. They are based on mmotm-2009-08-27.
Patch 1 adds multiple lists to struct per_cpu_pages, one per
migratetype that can be stored on the PCP lists.Patch 2 notes that the pcpu drain path check empty lists multiple times. The
patch reduces the number of checks by maintaining a count of free
lists encountered. Lists containing pages will then free multiple
pages in batchThe patches were tested with kernbench, netperf udp/tcp, hackbench and
sysbench. The netperf tests were not bound to any CPU in particular and
were run such that the results should be 99% confidence that the reported
results are within 1% of the estimated mean. sysbench was run with a
postgres background and read-only tests. Similar to netperf, it was run
multiple times so that it's 99% confidence results are within 1%. The
patches were tested on x86, x86-64 and ppc64 asx86: Intel Pentium D 3GHz with 8G RAM (no-brand machine)
kernbench - No significant difference, variance well within noise
netperf-udp - 1.34% to 2.28% gain
netperf-tcp - 0.45% to 1.22% gain
hackbench - Small variances, very close to noise
sysbench - Very small gainsx86-64: AMD Phenom 9950 1.3GHz with 8G RAM (no-brand machine)
kernbench - No significant difference, variance well within noise
netperf-udp - 1.83% to 10.42% gains
netperf-tcp - No conclusive until buffer >= PAGE_SIZE
4096 +15.83%
8192 + 0.34% (not significant)
16384 + 1%
hackbench - Small gains, very close to noise
sysbench - 0.79% to 1.6% gainppc64: PPC970MP 2.5GHz with 10GB RAM (it's a terrasoft powerstation)
kernbench - No significant difference, variance well within noise
netperf-udp - 2-3% gain for almost all buffer sizes tested
netperf-tcp - losses on small buffers, gains on larger buffers
possibly indicates some bad caching effect.
hackbench - No significant difference
sysbench - 2-4% gainThis patch:
Currently the per-cpu page allocator searches the PCP list for pages of
the correct migrate-type to reduce the possibility of pages being
inappropriate placed from a fragmentation perspective. This search is
potentially expensive in a fast-path and undesirable. Splitting the
per-cpu list into multiple lists increases the size of a per-cpu structure
and this was potentially a major problem at the time the search was
introduced. These problem has been mitigated as now only the necessary
number of structures is allocated for the running system.This patch replaces a list search in the per-cpu allocator with one list
per migrate type. The potential snag with this approach is when bulk
freeing pages. We round-robin free pages based on migrate type which has
little bearing on the cache hotness of the page and potentially checks
empty lists repeatedly in the event the majority of PCP pages are of one
type.Signed-off-by: Mel Gorman
Acked-by: Nick Piggin
Cc: Christoph Lameter
Cc: Minchan Kim
Cc: Pekka Enberg
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Currently, OOM logic callflow is here.
__out_of_memory()
select_bad_process() for each task
badness() calculate badness of one task
oom_kill_process() search child
oom_kill_task() kill target task and mm shared tasks with itexample, process-A have two thread, thread-A and thread-B and it have very
fat memory and each thread have following oom_adj and oom_score.thread-A: oom_adj = OOM_DISABLE, oom_score = 0
thread-B: oom_adj = 0, oom_score = very-highThen, select_bad_process() select thread-B, but oom_kill_task() refuse
kill the task because thread-A have OOM_DISABLE. Thus __out_of_memory()
call select_bad_process() again. but select_bad_process() select the same
task. It mean kernel fall in livelock.The fact is, select_bad_process() must select killable task. otherwise
OOM logic go into livelock.And root cause is, oom_adj shouldn't be per-thread value. it should be
per-process value because OOM-killer kill a process, not thread. Thus
This patch moves oomkilladj (now more appropriately named oom_adj) from
struct task_struct to struct signal_struct. it naturally prevent
select_bad_process() choose wrong task.Signed-off-by: KOSAKI Motohiro
Cc: Paul Menage
Cc: David Rientjes
Cc: KAMEZAWA Hiroyuki
Cc: Rik van Riel
Cc: Oleg Nesterov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
For mem_cgroup, shrink_zone() may call shrink_list() with nr_to_scan=1, in
which case shrink_list() _still_ calls isolate_pages() with the much
larger SWAP_CLUSTER_MAX. It effectively scales up the inactive list scan
rate by up to 32 times.For example, with 16k inactive pages and DEF_PRIORITY=12, (16k >> 12)=4.
So when shrink_zone() expects to scan 4 pages in the active/inactive list,
the active list will be scanned 4 pages, while the inactive list will be
(over) scanned SWAP_CLUSTER_MAX=32 pages in effect. And that could break
the balance between the two lists.It can further impact the scan of anon active list, due to the anon
active/inactive ratio rebalance logic in balance_pgdat()/shrink_zone():inactive anon list over scanned => inactive_anon_is_low() == TRUE
=> shrink_active_list()
=> active anon list over scannedSo the end result may be
- anon inactive => over scanned
- anon active => over scanned (maybe not as much)
- file inactive => over scanned
- file active => under scanned (relatively)The accesses to nr_saved_scan are not lock protected and so not 100%
accurate, however we can tolerate small errors and the resulted small
imbalanced scan rates between zones.Cc: Rik van Riel
Reviewed-by: KOSAKI Motohiro
Acked-by: Balbir Singh
Reviewed-by: Minchan Kim
Signed-off-by: KAMEZAWA Hiroyuki
Signed-off-by: Wu Fengguang
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Signed-off-by: Alexey Dobriyan
Acked-by: David Rientjes
Reviewed-by: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This is being done by allowing boot time allocations to specify that they
may want a sub-page sized amount of memory.Overall this seems more consistent with the other hash table allocations,
and allows making two supposedly mm-only variables really mm-only
(nr_{kernel,all}_pages).Signed-off-by: Jan Beulich
Cc: Ingo Molnar
Cc: "Eric W. Biederman"
Cc: Mel Gorman
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Sizing of memory allocations shouldn't depend on the number of physical
pages found in a system, as that generally includes (perhaps a huge amount
of) non-RAM pages. The amount of what actually is usable as storage
should instead be used as a basis here.Some of the calculations (i.e. those not intending to use high memory)
should likely even use (totalram_pages - totalhigh_pages).Signed-off-by: Jan Beulich
Acked-by: Rusty Russell
Acked-by: Ingo Molnar
Cc: Dave Airlie
Cc: Kyle McMartin
Cc: Jeremy Fitzhardinge
Cc: Pekka Enberg
Cc: Hugh Dickins
Cc: "David S. Miller"
Cc: Patrick McHardy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Make page_has_private() return a true boolean value and remove the double
negations from the two callsites using it for arithmetic.Signed-off-by: Johannes Weiner
Cc: Christoph Lameter
Reviewed-by: Christoph Lameter
Reviewed-by: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
page_is_file_cache() has been used for both boolean checks and LRU
arithmetic, which was always a bit weird.Now that page_lru_base_type() exists for LRU arithmetic, make
page_is_file_cache() a real predicate function and adjust the
boolean-using callsites to drop those pesky double negations.Signed-off-by: Johannes Weiner
Reviewed-by: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Instead of abusing page_is_file_cache() for LRU list index arithmetic, add
another helper with a more appropriate name and convert the non-boolean
users of page_is_file_cache() accordingly.This new helper gives the LRU base type a page is supposed to live on,
inactive anon or inactive file.[hugh.dickins@tiscali.co.uk: convert del_page_from_lru() also]
Signed-off-by: Johannes Weiner
Reviewed-by: Rik van Riel
Cc: Minchan Kim
Reviewed-by: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The kzalloc mempool zeros items when they are initially allocated, but
does not rezero used items that are returned to the pool. Consequently
mempool_alloc()s may return non-zeroed memory.Since there are/were only two in-tree users for
mempool_create_kzalloc_pool(), and 'fixing' this in a way that will
re-zero used (but not new) items before first use is non-trivial, just
remove it.Signed-off-by: Sage Weil
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The page allocation trace event reports that a page was successfully
allocated but it does not specify where it came from. When analysing
performance, it can be important to distinguish between pages coming from
the per-cpu allocator and pages coming from the buddy lists as the latter
requires the zone lock to the taken and more data structures to be
examined.This patch adds a trace event for __rmqueue reporting when a page is being
allocated from the buddy lists. It distinguishes between being called to
refill the per-cpu lists or whether it is a high-order allocation.
Similarly, this patch adds an event to catch when the PCP lists are being
drained a little and pages are going back to the buddy lists.This is trickier to draw conclusions from but high activity on those
events could explain why there were a large number of cache misses on a
page-allocator-intensive workload. The coalescing and splitting of
buddies involves a lot of writing of page metadata and cache line bounces
not to mention the acquisition of an interrupt-safe lock necessary to
enter this path.[akpm@linux-foundation.org: fix build]
Signed-off-by: Mel Gorman
Acked-by: Rik van Riel
Reviewed-by: Ingo Molnar
Cc: Larry Woodman
Cc: Peter Zijlstra
Cc: Li Ming Chun
Reviewed-by: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fragmentation avoidance depends on being able to use free pages from lists
of the appropriate migrate type. In the event this is not possible,
__rmqueue_fallback() selects a different list and in some circumstances
change the migratetype of the pageblock. Simplistically, the more times
this event occurs, the more likely that fragmentation will be a problem
later for hugepage allocation at least but there are other considerations
such as the order of page being split to satisfy the allocation.This patch adds a trace event for __rmqueue_fallback() that reports what
page is being used for the fallback, the orders of relevant pages, the
desired migratetype and the migratetype of the lists being used, whether
the pageblock changed type and whether this event is important with
respect to fragmentation avoidance or not. This information can be used
to help analyse fragmentation avoidance and help decide whether
min_free_kbytes should be increased or not.Signed-off-by: Mel Gorman
Acked-by: Rik van Riel
Reviewed-by: Ingo Molnar
Cc: Larry Woodman
Cc: Peter Zijlstra
Cc: Li Ming Chun
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch adds trace events for the allocation and freeing of pages,
including the freeing of pagevecs. Using the events, it will be known
what struct page and pfns are being allocated and freed and what the call
site was in many cases.The page alloc tracepoints be used as an indicator as to whether the
workload was heavily dependant on the page allocator or not. You can make
a guess based on vmstat but you can't get a per-process breakdown.
Depending on the call path, the call_site for page allocation may be
__get_free_pages() instead of a useful callsite. Instead of passing down
a return address similar to slab debugging, the user should enable the
stacktrace and seg-addr options to get a proper stack trace.The pagevec free tracepoint has a different usecase. It can be used to
get a idea of how many pages are being dumped off the LRU and whether it
is kswapd doing the work or a process doing direct reclaim.Signed-off-by: Mel Gorman
Acked-by: Rik van Riel
Reviewed-by: Ingo Molnar
Cc: Larry Woodman
Cc: Peter Zijlstra
Cc: Li Ming Chun
Reviewed-by: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The function free_cold_page() has no callers so delete it.
Signed-off-by: Mel Gorman
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Just as the swapoff system call allocates many pages of RAM to various
processes, perhaps triggering OOM, so "echo 2 >/sys/kernel/mm/ksm/run"
(unmerge) is liable to allocate many pages of RAM to various processes,
perhaps triggering OOM; and each is normally run from a modest admin
process (swapoff or shell), easily repeated until it succeeds.So treat unmerge_and_remove_all_rmap_items() in the same way that we treat
try_to_unuse(): generalize PF_SWAPOFF to PF_OOM_ORIGIN, and bracket both
with that, to ask the OOM killer to kill them first, to prevent them from
spawning more and more OOM kills.Signed-off-by: Hugh Dickins
Acked-by: Izik Eidus
Cc: Andrea Arcangeli
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
A few cleanups, given the munlock fix: the comment on ksm_test_exit() no
longer applies, and it can be made private to ksm.c; there's no more
reference to mmu_gather or tlb.h, and mmap.c doesn't need ksm.h.Signed-off-by: Hugh Dickins
Acked-by: Izik Eidus
Cc: Andrea Arcangeli
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
