Hugh Dickins [Thu, 7 Feb 2008 08:14:22 +0000 (00:14 -0800)]
memcgroup: fix hang with shmem/tmpfs
The memcgroup regime relies upon a cgroup reclaiming pages from itself within
add_to_page_cache: which may involve some waiting. Whereas shmem and tmpfs
rely upon using add_to_page_cache while holding a spinlock: when it cannot
wait. The consequence is that when a cgroup reaches its limit, shmem_getpage
just hangs - unless there is outside memory pressure too, neither kswapd nor
radix_tree_preload get it out of the retry loop.
In most cases we can mem_cgroup_cache_charge the page waitably first, to
attach the page_cgroup in advance, so add_to_page_cache will do no more than
increment a count; then mem_cgroup_uncharge_page after (in both success and
failure cases) to balance the books again.
And where there used to be a congestion_wait for kswapd (recently made
redundant by radix_tree_preload), use mem_cgroup_cache_charge with NULL page
to go through a cycle of allocation and freeing, without accounting to any
particular page, and without updating the statistics vector. This brings the
cgroup below its limit so the next try usually succeeds.
Hugh Dickins [Thu, 7 Feb 2008 08:14:19 +0000 (00:14 -0800)]
memcgroup: tidy up mem_cgroup_charge_common
Tidy up mem_cgroup_charge_common before extending it. Adjust some comments,
but mainly clean up its loop: I've an aversion to loops full of continues,
then a break or a goto at the bottom. And the is_atomic test should be on the
__GFP_WAIT bit, not GFP_ATOMIC bits.
memory cgroup enhancements: remember "a page is charged as page cache"
Add a flag to page_cgroup to remember "this page is
charged as cache."
cache here includes page caches and swap cache.
This is useful for implementing precise accounting in memory cgroup.
TODO:
distinguish page-cache and swap-cache
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Pavel Emelianov <xemul@openvz.org> Cc: Paul Menage <menage@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Kirill Korotaev <dev@sw.ru> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: David Rientjes <rientjes@google.com> Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
memory cgroup enhancements: fix zone handling in try_to_free_mem_cgroup_page
Because NODE_DATA(node)->node_zonelists[] is guaranteed to contain all
necessary zones, it is not necessary to use for_each_online_node.
And this for_each_online_node() makes reclaim routine start always
from node 0. This is not good. This patch makes reclaim start from
caller's node and just use usual (default) zonelist order.
[akpm@linux-foundation.org: fix warning] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Pavel Emelianov <xemul@openvz.org> Cc: Paul Menage <menage@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Kirill Korotaev <dev@sw.ru> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: David Rientjes <rientjes@google.com> Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hugh Dickins [Thu, 7 Feb 2008 08:14:13 +0000 (00:14 -0800)]
memcgroup: revert swap_state mods
If we're charging rss and we're charging cache, it seems obvious that we
should be charging swapcache - as has been done. But in practice that
doesn't work out so well: both swapin readahead and swapoff leave the
majority of pages charged to the wrong cgroup (the cgroup that happened to
read them in, rather than the cgroup to which they belong).
(Which is why unuse_pte's GFP_KERNEL while holding pte lock never showed up
as a problem: no allocation was ever done there, every page read being
already charged to the cgroup which initiated the swapoff.)
It all works rather better if we leave the charging to do_swap_page and
unuse_pte, and do nothing for swapcache itself: revert mm/swap_state.c to
what it was before the memory-controller patches. This also speeds up
significantly a contained process working at its limit: because it no
longer needs to keep waiting for swap writeback to complete.
Is it unfair that swap pages become uncharged once they're unmapped, even
though they're still clearly private to particular cgroups? For a short
while, yes; but PageReclaim arranges for those pages to go to the end of
the inactive list and be reclaimed soon if necessary.
shmem/tmpfs pages are a distinct case: their charging also benefits from
this change, but their second life on the lists as swapcache pages may
prove more unfair - that I need to check next.
Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: Pavel Emelianov <xemul@openvz.org> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Kirill Korotaev <dev@sw.ru> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: David Rientjes <rientjes@google.com> Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hugh Dickins [Thu, 7 Feb 2008 08:14:12 +0000 (00:14 -0800)]
memcgroup: fix zone isolation OOM
mem_cgroup_charge_common shows a tendency to OOM without good reason, when
a memhog goes well beyond its rss limit but with plenty of swap available.
Seen on x86 but not on PowerPC; seen when the next patch omits swapcache
from memcgroup, but we presume it can happen without.
mem_cgroup_isolate_pages is not quite satisfying reclaim's criteria for OOM
avoidance. Already it has to scan beyond the nr_to_scan limit when it
finds a !LRU page or an active page when handling inactive or an inactive
page when handling active. It needs to do exactly the same when it finds a
page from the wrong zone (the x86 tests had two zones, the PowerPC tests
had only one).
Don't increment scan and then decrement it in these cases, just move the
incrementation down. Fix recent off-by-one when checking against
nr_to_scan. Cut out "Check if the meta page went away from under us",
presumably left over from early debugging: no amount of such checks could
save us if this list really were being updated without locking.
This change does make the unlimited scan while holding two spinlocks
even worse - bad for latency and bad for containment; but that's a
separate issue which is better left to be fixed a little later.
Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: Pavel Emelianov <xemul@openvz.org> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Kirill Korotaev <dev@sw.ru> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: David Rientjes <rientjes@google.com> Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
bugfix for memory cgroup controller: avoid !PageLRU page in mem_cgroup_isolate_pages
This patch makes mem_cgroup_isolate_pages() to be
- ignore !PageLRU pages.
- fixes the bug that isolation makes no progress if page_zone(page) != zone
page once find. (just increment scan in this case.)
kswapd and memory migration removes a page from list when it handles
a page for reclaiming/migration.
Because __isolate_lru_page() doesn't moves page !PageLRU pages, it will
be safe to avoid touching !PageLRU() page and its page_cgroup.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Pavel Emelianov <xemul@openvz.org> Cc: Paul Menage <menage@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Kirill Korotaev <dev@sw.ru> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: David Rientjes <rientjes@google.com> Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
bugfix for memory cgroup controller: migration under memory controller fix
While using memory control cgroup, page-migration under it works as following.
==
1. uncharge all refs at try to unmap.
2. charge regs again remove_migration_ptes()
==
This is simple but has following problems.
==
The page is uncharged and charged back again if *mapped*.
- This means that cgroup before migration can be different from one after
migration
- If page is not mapped but charged as page cache, charge is just ignored
(because not mapped, it will not be uncharged before migration)
This is memory leak.
==
This patch tries to keep memory cgroup at page migration by increasing
one refcnt during it. 3 functions are added.
mem_cgroup_prepare_migration() --- increase refcnt of page->page_cgroup
mem_cgroup_end_migration() --- decrease refcnt of page->page_cgroup
mem_cgroup_page_migration() --- copy page->page_cgroup from old page to
new page.
During migration
- old page is under PG_locked.
- new page is under PG_locked, too.
- both old page and new page is not on LRU.
These 3 facts guarantee that page_cgroup() migration has no race.
Tested and worked well in x86_64/fake-NUMA box.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Pavel Emelianov <xemul@openvz.org> Cc: Paul Menage <menage@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Kirill Korotaev <dev@sw.ru> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: David Rientjes <rientjes@google.com> Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rik van Riel [Thu, 7 Feb 2008 08:14:08 +0000 (00:14 -0800)]
kswapd should only wait on IO if there is IO
The current kswapd (and try_to_free_pages) code has an oddity where the
code will wait on IO, even if there is no IO in flight. This problem is
notable especially when the system scans through many unfreeable pages,
causing unnecessary stalls in the VM.
Additionally, tasks without __GFP_FS or __GFP_IO in the direct reclaim path
will sleep if a significant number of pages are encountered that should be
written out. This gives kswapd a chance to write out those pages, while
the direct reclaim task sleeps.
Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Rientjes [Thu, 7 Feb 2008 08:14:07 +0000 (00:14 -0800)]
oom: add sysctl to enable task memory dump
Adds a new sysctl, 'oom_dump_tasks', that enables the kernel to produce a
dump of all system tasks (excluding kernel threads) when performing an
OOM-killing. Information includes pid, uid, tgid, vm size, rss, cpu,
oom_adj score, and name.
This is helpful for determining why there was an OOM condition and which
rogue task caused it.
It is configurable so that large systems, such as those with several
thousand tasks, do not incur a performance penalty associated with dumping
data they may not desire.
If an OOM was triggered as a result of a memory controller, the tasklist
shall be filtered to exclude tasks that are not a member of the same
cgroup.
Cc: Andrea Arcangeli <andrea@suse.de> Cc: Christoph Lameter <clameter@sgi.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Rientjes [Thu, 7 Feb 2008 08:14:06 +0000 (00:14 -0800)]
memcontrol: move oom task exclusion to tasklist scan
Creates a helper function to return non-zero if a task is a member of a
memory controller:
int task_in_mem_cgroup(const struct task_struct *task,
const struct mem_cgroup *mem);
When the OOM killer is constrained by the memory controller, the exclusion
of tasks that are not a member of that controller was previously misplaced
and appeared in the badness scoring function. It should be excluded
during the tasklist scan in select_bad_process() instead.
[akpm@linux-foundation.org: build fix] Cc: Christoph Lameter <clameter@sgi.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Balbir Singh [Thu, 7 Feb 2008 08:14:05 +0000 (00:14 -0800)]
memory controller BUG_ON()
Move mem_controller_cache_charge() above radix_tree_preload().
radix_tree_preload() disables preemption, even though the gfp_mask passed
contains __GFP_WAIT, we cannot really do __GFP_WAIT allocations, thus we
hit a BUG_ON() in kmem_cache_alloc().
This patch moves mem_controller_cache_charge() to above radix_tree_preload()
for cache charging.
Hugh Dickins [Thu, 7 Feb 2008 08:14:04 +0000 (00:14 -0800)]
memcgroup: reinstate swapoff mod
This patch reinstates the "swapoff: scan ptes preemptibly" mod we started
with: in due course it should be rendered down into the earlier patches,
leaving us with a more straightforward mem_cgroup_charge mod to unuse_pte,
allocating with GFP_KERNEL while holding no spinlock and no atomic kmap.
Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: Pavel Emelianov <xemul@openvz.org> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Kirill Korotaev <dev@sw.ru> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: David Rientjes <rientjes@google.com> Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Rientjes [Thu, 7 Feb 2008 08:14:03 +0000 (00:14 -0800)]
memcontrol: move mm_cgroup to header file
Inline functions must preceed their use, so mm_cgroup() should be defined
in linux/memcontrol.h.
include/linux/memcontrol.h:48: warning: 'mm_cgroup' declared inline after
being called
include/linux/memcontrol.h:48: warning: previous declaration of
'mm_cgroup' was here
Balbir Singh [Thu, 7 Feb 2008 08:14:02 +0000 (00:14 -0800)]
Memory controller: make charging gfp mask aware
Nick Piggin pointed out that swap cache and page cache addition routines
could be called from non GFP_KERNEL contexts. This patch makes the
charging routine aware of the gfp context. Charging might fail if the
cgroup is over it's limit, in which case a suitable error is returned.
This patch was tested on a Powerpc box. I am still looking at being able
to test the path, through which allocations happen in non GFP_KERNEL
contexts.
[kamezawa.hiroyu@jp.fujitsu.com: problem with ZONE_MOVABLE] Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Pavel Emelianov <xemul@openvz.org> Cc: Paul Menage <menage@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Kirill Korotaev <dev@sw.ru> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: David Rientjes <rientjes@google.com> Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Balbir Singh [Thu, 7 Feb 2008 08:14:01 +0000 (00:14 -0800)]
Memory controller: make page_referenced() cgroup aware
Make page_referenced() cgroup aware. Without this patch, page_referenced()
can cause a page to be skipped while reclaiming pages. This patch ensures
that other cgroups do not hold pages in a particular cgroup hostage. It
is required to ensure that shared pages are freed from a cgroup when they
are not actively referenced from the cgroup that brought them in
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Pavel Emelianov <xemul@openvz.org> Cc: Paul Menage <menage@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Kirill Korotaev <dev@sw.ru> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: David Rientjes <rientjes@google.com> Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Balbir Singh [Thu, 7 Feb 2008 08:13:57 +0000 (00:13 -0800)]
Memory controller improve user interface
Change the interface to use bytes instead of pages. Page sizes can vary
across platforms and configurations. A new strategy routine has been added
to the resource counters infrastructure to format the data as desired.
Suggested by David Rientjes, Andrew Morton and Herbert Poetzl
Tested on a UML setup with the config for memory control enabled.
[kamezawa.hiroyu@jp.fujitsu.com: possible race fix in res_counter] Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Pavel Emelianov <xemul@openvz.org> Cc: Paul Menage <menage@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Kirill Korotaev <dev@sw.ru> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: David Rientjes <rientjes@google.com> Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Balbir Singh [Thu, 7 Feb 2008 08:13:56 +0000 (00:13 -0800)]
Memory controller: add per cgroup LRU and reclaim
Add the page_cgroup to the per cgroup LRU. The reclaim algorithm has
been modified to make the isolate_lru_pages() as a pluggable component. The
scan_control data structure now accepts the cgroup on behalf of which
reclaims are carried out. try_to_free_pages() has been extended to become
cgroup aware.
[akpm@linux-foundation.org: fix warning]
[Lee.Schermerhorn@hp.com: initialize all scan_control's isolate_pages member]
[bunk@kernel.org: make do_try_to_free_pages() static]
[hugh@veritas.com: memcgroup: fix try_to_free order]
[kamezawa.hiroyu@jp.fujitsu.com: this unlock_page_cgroup() is unnecessary] Signed-off-by: Pavel Emelianov <xemul@openvz.org> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Kirill Korotaev <dev@sw.ru> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: David Rientjes <rientjes@google.com> Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Balbir Singh [Thu, 7 Feb 2008 08:13:53 +0000 (00:13 -0800)]
Memory controller: memory accounting
Add the accounting hooks. The accounting is carried out for RSS and Page
Cache (unmapped) pages. There is now a common limit and accounting for both.
The RSS accounting is accounted at page_add_*_rmap() and page_remove_rmap()
time. Page cache is accounted at add_to_page_cache(),
__delete_from_page_cache(). Swap cache is also accounted for.
Each page's page_cgroup is protected with the last bit of the
page_cgroup pointer, this makes handling of race conditions involving
simultaneous mappings of a page easier. A reference count is kept in the
page_cgroup to deal with cases where a page might be unmapped from the RSS
of all tasks, but still lives in the page cache.
Credits go to Vaidyanathan Srinivasan for helping with reference counting work
of the page cgroup. Almost all of the page cache accounting code has help
from Vaidyanathan Srinivasan.
[hugh@veritas.com: fix swapoff breakage]
[akpm@linux-foundation.org: fix locking] Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Pavel Emelianov <xemul@openvz.org> Cc: Paul Menage <menage@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Kirill Korotaev <dev@sw.ru> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: David Rientjes <rientjes@google.com> Cc: <Valdis.Kletnieks@vt.edu> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hugh Dickins [Thu, 7 Feb 2008 08:13:48 +0000 (00:13 -0800)]
memcgroup: temporarily revert swapoff mod
This patch precisely reverts the "swapoff: scan ptes preemptibly" patch
just presented. It's a temporary measure to allow existing memory
controller patches to apply without rejects: in due course they should be
rendered down into one sensible patch, and this reversion disappear.
Paul Menage [Thu, 7 Feb 2008 08:13:45 +0000 (00:13 -0800)]
cgroups: move cgroups destroy() callbacks to cgroup_diput()
Move the calls to the cgroup subsystem destroy() methods from
cgroup_rmdir() to cgroup_diput(). This allows control file reads and
writes to access their subsystem state without having to be concerned with
locking against cgroup destruction - the control file dentry will keep the
cgroup and its subsystem state objects alive until the file is closed.
The documentation is updated to reflect the changed semantics of destroy();
additionally the locking comments for destroy() and some other methods were
clarified and decrustified.
Signed-off-by: Paul Menage <menage@google.com> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Paul Jackson [Thu, 7 Feb 2008 08:13:44 +0000 (00:13 -0800)]
cgroup simplify space stripping
Simplify the space stripping code in cgroup file write.
[akpm@linux-foundation.org: s/BUG_ON/BUILD_BUG_ON/] Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Paul Jackson [Thu, 7 Feb 2008 08:13:44 +0000 (00:13 -0800)]
cgroup brace coding style fix
Coding style fix - one line conditionals don't get braces.
Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Adrian Bunk [Thu, 7 Feb 2008 08:13:43 +0000 (00:13 -0800)]
kernel/cgroup.c: remove dead code
This patch removes dead code spotted by the Coverity checker
(look at the "(nbytes >= PATH_MAX)" check).
Signed-off-by: Adrian Bunk <bunk@kernel.org> Cc: Paul Jackson <pj@sgi.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Randy Dunlap [Thu, 7 Feb 2008 08:13:42 +0000 (00:13 -0800)]
email-clients.txt: sylpheed is OK at IMAP
This comment is not helpful (no reason given) and is incorrect.
Just stick to facts that are useful regarding working on Linux.
(akpm: I've used sylpheed+imap for years)
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Acked-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Randy Dunlap [Thu, 7 Feb 2008 08:13:42 +0000 (00:13 -0800)]
kernel-doc: warn on badly formatted short description
Make kernel-doc warn when a function/struct/union/typedef does not contain
a properly formatted short description, such as:
* scsi_devinfo: set up the dynamic device list
or
* scsi_devinfo -
This warning is only generated when verbose (-v) mode is used.
Also explain the -v command line option in the -h output.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Randy Dunlap [Thu, 7 Feb 2008 08:13:41 +0000 (00:13 -0800)]
kernel-doc: prevent duplicate description: output
Prevent duplicate output of a Description: section when there is a "blank"
("*") line between the initial function name/description line and the
"Description:" header.
Test case: drivers/scsi/scsi_devinfo.c::scsi_init_devinfo().
Rob Landley hit this while he was producing SCSI kernel-doc.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
J. Bruce Fields [Thu, 7 Feb 2008 08:13:40 +0000 (00:13 -0800)]
REPORTING-BUGS: cc the mailing list too
People should also cc relevant mailing lists when reporting bugs.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
J. Bruce Fields [Thu, 7 Feb 2008 08:13:37 +0000 (00:13 -0800)]
Documentation: create new scheduler/ subdirectory
The top-level Documentation/ directory is unmanageably large, so we
should take any obvious opportunities to move stuff into subdirectories.
These sched-*.txt files seem an obvious easy case.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Cc: Ingo Molnar <mingo@elte.hu> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
J. Bruce Fields [Thu, 7 Feb 2008 08:13:35 +0000 (00:13 -0800)]
Documentation: move sharedsubtrees.txt to filesystems/
This documentation is also vfs-related.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
J. Bruce Fields [Thu, 7 Feb 2008 08:13:35 +0000 (00:13 -0800)]
Documentation: move dnotify.txt to filesystems/
I'm inclined to think dnotify belongs in filesystems/.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Erez Zadok [Thu, 7 Feb 2008 08:13:25 +0000 (00:13 -0800)]
VFS: factor out three helpers for FIBMAP/FIONBIO/FIOASYNC file ioctls
Factor out file-specific ioctl code into smaller helper functions, away from
file_ioctl(). This helps code readability and also reduces indentation inside
case statements.
Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Erez Zadok [Thu, 7 Feb 2008 08:13:25 +0000 (00:13 -0800)]
VFS: swap do_ioctl and vfs_ioctl names
Rename old vfs_ioctl to do_ioctl, because the comment above it clearly
indicates that it is an internal function not to be exported to modules;
therefore it should have a more traditional do_XXX name. The new do_ioctl
is exported in fs.h but not to modules.
Rename the old do_ioctl to vfs_ioctl because the names vfs_XXX should
preferably be reserved to callable VFS functions which modules may call, as
many other vfs_XXX functions already do. Export the new vfs_ioctl to GPL
modules so others can use it (including Unionfs and eCryptfs). Add DocBook
for new vfs_ioctl.
[akpm@linux-foundation.org: fix build] Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Philipp Zabel [Thu, 7 Feb 2008 08:13:22 +0000 (00:13 -0800)]
DS1WM: decouple host IRQ and INTR active state settings
The DS1WM driver incorrectly infers the IAS bit (1-wire interrupt active
high) from IRQ settings. There are devices that have IAS=0 but still need
the IRQ to trigger on a rising edge. With this patch, machines with DS1WM
that need IAS=1 have to set .active_high=1 in the ds1wm_platform_data.
Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com> Acked-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Acked-by: Matt Reimer <mreimer@vpop.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pavel Emelyanov [Thu, 7 Feb 2008 08:13:21 +0000 (00:13 -0800)]
gfs2: make gfs2_glock.gl_owner_pid be a struct pid *
The gl_owner_pid field is used to get the lock owning task by its pid, so make
it in a proper manner, i.e. by using the struct pid pointer and pid_task()
function.
The pid_task() becomes exported for the gfs2 module.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Removed CAPACITY_LEVEL from every other code, leaving the array with sysfs
attributes with one more entry than the number of enums in power_supply.h.
This leads to some attributes containing the value of the attribute right
after it. For example, temp_ambient would have the value of
time_to_empty_now. In my case, I had time_to_full_avg have the value which
should be in model_name, when the former was usually empty.
Cc: Andres Salomon <dilinger@debian.org> Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pavel Emelyanov [Thu, 7 Feb 2008 08:13:19 +0000 (00:13 -0800)]
gfs2: make gfs2_holder.gh_owner_pid be a struct pid *
The gl_owner_pid field is used to get the holder task by its pid and check
whether the current is a holder, so make it in a proper manner, i.e. via the
struct pid * manipulations.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds [Thu, 7 Feb 2008 02:06:58 +0000 (18:06 -0800)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
9p: fix p9_printfcall export
9p: transport API reorganization
9p: add remove function to trans_virtio
9p: Convert semaphore to spinlock for p9_idpool
9p: fix mmap to be read-only
9p: add support for sticky bit
9p: Fix soft lockup in virtio transport
9p: fix bug in attach-per-user
9p: block-based virtio client
9p: create transport rpc cut-thru
9p: fix bug in p9_clone_stat
This merges the mux.c (including the connection interface) with trans_fd
in preparation for transport API changes. Ultimately, trans_fd will need
to be rewritten to clean it up and simplify the implementation, but this
reorganization is viewed as the first step.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Request from rusty:
Just cleaning up patches for 2.6.25 merge, and noticed that
net/9p/trans_virtio.c doesn't have a remove function. This will crash when
removing the module (console doesn't have one because it can't really be
removed).
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Anthony Liguori [Thu, 7 Feb 2008 01:25:04 +0000 (19:25 -0600)]
9p: Convert semaphore to spinlock for p9_idpool
When booting from v9fs, down_interruptible in p9_idpool_get() triggered a BUG
as it was being called with IRQs disabled. A spinlock seems like the right
thing to be using since the idr functions go out of their way not to sleep.
This patch eliminates the BUG by converting the semaphore to a spinlock.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> Acked-by: Eric Van Hensbergen <ericvh@gmail.com>
v9fs was allowing writable mmap which could lead to kernel BUG() cases.
This sets the mmap function to generic_file_readonly_mmap which (correctly)
returns an error to applications which open mmap for writing.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Anthony Liguori [Thu, 7 Feb 2008 01:25:06 +0000 (19:25 -0600)]
9p: add support for sticky bit
GDM gets unhappy if /var/gdm doesn't have the sticky bit set. This patch adds
support for the sticky bit in much the same way setuid/setgid is supported.
With this patch, I can launch X from a v9fs rootfs (although I quickly run out
of fds in the server once gnome starts up).
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> Acked-by: Eric Van Hensbergen <ericvh@gmail.com>
When a new user attached at a directory other than the root, he would end
up in the parent directory of the cwd. This was due to a logic error in
the code which attaches the user at the mount point and walks back to the
cwd. This patch fixes that.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
The .rodata section really should just be read only; the config option
is there to make breaking up the 2Mb page an option (so people whos machines
give more performance for the 2Mb case can opt to do so).
But when the page gets split anyway, this is no longer an issue, so
clean up the code and remove the ifdefs
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
x86: replace privileged instructions with paravirt macros
The ENTRY(native_iret) macro adds alignment padding before the iretq
instruction, so "iret_label" no longer points exactly at the instruction.
It was sloppy to leave the old "iret_label" label behind when replacing
its nearby use. Removing it would have revealed the other use of the
label later in the file, and upon noticing that use, anyone exercising
the minimum of attention to detail expected of anyone touching this
subtle code would realize it needed to change as well.
Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Harvey Harrison [Wed, 6 Feb 2008 21:39:44 +0000 (22:39 +0100)]
x86: fix sparse warnings in powernow-k8.c
arch/x86/kernel/cpu/cpufreq/powernow-k8.c:830:7: warning: symbol 'hi' shadows an earlier one
arch/x86/kernel/cpu/cpufreq/powernow-k8.c:824:6: originally declared here
arch/x86/kernel/cpu/cpufreq/powernow-k8.c:830:15: warning: symbol 'lo' shadows an earlier one
arch/x86/kernel/cpu/cpufreq/powernow-k8.c:824:14: originally declared here
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Harvey Harrison [Wed, 6 Feb 2008 21:39:44 +0000 (22:39 +0100)]
x86: fix sparse error in traps_32.c
This was being used to ensure the proper alignment of the FXSAVE/FXRSTOR data.
This would create a sparse error in the _correct_ cases, hiding further
warnings. Use BUILD_BUG_ON instead.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Roland McGrath [Wed, 6 Feb 2008 21:39:44 +0000 (22:39 +0100)]
x86 ptrace: disallow null cs/ss
In my revamp of the x86 ptrace code for setting register values,
I accidentally omitted a check that was there in the old code.
Allowing %cs to be 0 causes a bad crash in recovery from iret failure.
This patch fixes that regression against 2.6.24, and adds a comment
that should help prevent this subtlety from being overlooked again.
Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Jiri Kosina [Wed, 6 Feb 2008 21:39:44 +0000 (22:39 +0100)]
brk: check the lower bound properly
There is a check in sys_brk(), that tries to make sure that we do not
underflow the area that is dedicated to brk heap.
The check is however wrong, as it assumes that brk area starts immediately
after the end of the code (+bss), which is wrong for example in
environments with randomized brk start. The proper way is to check whether
the address is not below the start_brk address.
Thomas Gleixner [Wed, 6 Feb 2008 21:39:43 +0000 (22:39 +0100)]
x86: make spurious fault handler aware of large mappings
In very rare cases, on certain CPUs, we could end up in the spurious
fault handler and ignore a large pud/pmd mapping. The resulting pte
pointer points into the mapped physical space and dereferencing it
will fault recursively.
Make the code aware of large mappings and do the permission check
on the pmd/pud entry, when a large pud/pmd mapping is detected.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Roland McGrath [Wed, 6 Feb 2008 21:39:43 +0000 (22:39 +0100)]
x86: make traps on entry code be debuggable in user space, 64-bit
Unify the x86-64 behavior for 32-bit processes that set
bogus %cs/%ss values (the only ones that can fault in iret)
match what the native i386 behavior is. (do not kill the task
via do_exit but generate a SIGSEGV signal)
[ tglx@linutronix.de: build fix ]
Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Linus Torvalds [Wed, 6 Feb 2008 19:16:11 +0000 (11:16 -0800)]
Merge branch 'async-tx-for-linus' of git://lost.foo-projects.org/~dwillia2/git/iop into fix
* 'async-tx-for-linus' of git://lost.foo-projects.org/~dwillia2/git/iop:
async_tx: allow architecture specific async_tx_find_channel implementations
async_tx: replace 'int_en' with operation preparation flags
async_tx: kill tx_set_src and tx_set_dest methods
async_tx: kill ASYNC_TX_ASSUME_COHERENT
iop-adma: use LIST_HEAD instead of LIST_HEAD_INIT
async_tx: use LIST_HEAD instead of LIST_HEAD_INIT
async_tx: fix compile breakage, mark do_async_xor __always_inline
Linus Torvalds [Wed, 6 Feb 2008 18:48:34 +0000 (10:48 -0800)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/selinux-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/selinux-2.6:
SELinux: Remove security_get_policycaps()
security: allow Kconfig to set default mmap_min_addr protection
Linus Torvalds [Wed, 6 Feb 2008 18:47:46 +0000 (10:47 -0800)]
Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
ata_piix.c:piix_init_one() must be __devinit
sata_via.c: Remove missleading comment.
libata-core: unblacklist HITACHI drives
sata_nv: fix ATAPI issues with memory over 4GB (v7)
ata: drivers/ata/sata_mv.c needs dmapool.h
libata: kill now unused n_iter and fix sata_fsl
ahci: fix CAP.NP and PI handling
sata_mv: Support SoC controllers
Rename: linux/pata_platform.h to linux/ata_platform.h
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (35 commits)
virtio net: fix oops on interface-up
Fix PHY Lib support for gianfar and ucc_geth
forcedeth: preserve registers
forcedeth: phy status fix
forcedeth: restart tx/rx
ipvs: Make wrr "no available servers" error message rate-limited
[PPPOL2TP]: Label unused warning when CONFIG_PROC_FS is not set.
[NET_SCHED]: cls_flow: support classification based on VLAN tag
[VLAN]: Constify skb argument to vlan_get_tag()
[NET_SCHED]: cls_flow: fix key mask validity check
[NET_SCHED]: em_meta: fix compile warning
b43: Fix DMA for 30/32-bit DMA engines
b43: fix build with CONFIG_SSB_PCIHOST=n
mac80211: Is not EXPERIMENTAL anymore
iwl3945-base.c: fix off-by-one errors
b43legacy: fix DMA slot resource leakage
b43legacy: drop packets we are not able to encrypt
b43legacy: fix suspend/resume
b43legacy: fix PIO crash
Generic HDLC - use random_ether_addr()
...
projects / linux-2.6 / log