Skip to content

R
raspberrypi-kernel

openeuler / raspberrypi-kernel

通知 13
Star 1
Fork 0
R
raspberrypi-kernel
切换分支/标签
  1. 25 9月, 2014 1 次提交
    • Z
      cpuset: PF_SPREAD_PAGE and PF_SPREAD_SLAB should be atomic flags · 2ad654bc
      由 Zefan Li 提交于 
      When we change cpuset.memory_spread_{page,slab}, cpuset will flip
PF_SPREAD_{PAGE,SLAB} bit of tsk->flags for each task in that cpuset.
This should be done using atomic bitops, but currently we don't,
which is broken.

Tetsuo reported a hard-to-reproduce kernel crash on RHEL6, which happened
when one thread tried to clear PF_USED_MATH while at the same time another
thread tried to flip PF_SPREAD_PAGE/PF_SPREAD_SLAB. They both operate on
the same task.

Here's the full report:
https://lkml.org/lkml/2014/9/19/230

To fix this, we make PF_SPREAD_PAGE and PF_SPREAD_SLAB atomic flags.

v4:
- updated mm/slab.c. (Fengguang Wu)
- updated Documentation.

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Miao Xie <miaox@cn.fujitsu.com>
Cc: Kees Cook <keescook@chromium.org>
Fixes: 950592f7 ("cpusets: update tasks' page/slab spread flags in time")
Cc: <stable@vger.kernel.org> # 2.6.31+
Reported-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NZefan Li <lizefan@huawei.com>
Signed-off-by: NTejun Heo <tj@kernel.org>
      2ad654bc
  3. 19 6月, 2013 1 次提交
  5. 13 12月, 2012 1 次提交
  7. 29 3月, 2012 1 次提交
  9. 24 7月, 2011 1 次提交
  11. 16 6月, 2011 1 次提交
  13. 09 3月, 2011 1 次提交
  15. 04 8月, 2010 1 次提交
    • J
      Documentation: update broken web addresses. · 0ea6e611
      由 Justin P. Mattock 提交于 
      Below you will find an updated version from the original series bunching all patches into one big patch
updating broken web addresses that are located in Documentation/*
Some of the addresses date as far far back as 1995 etc... so searching became a bit difficult,
the best way to deal with these is to use web.archive.org to locate these addresses that are outdated.
Now there are also some addresses pointing to .spec files some are located, but some(after searching
on the companies site)where still no where to be found. In this case I just changed the address
to the company site this way the users can contact the company and they can locate them for the users.
Signed-off-by: NJustin P. Mattock <justinmattock@gmail.com>
Signed-off-by: NThomas Weber <weber@corscience.de>
Signed-off-by: NMike Frysinger <vapier.adi@gmail.com>
Cc: Paulo Marques <pmarques@grupopie.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Michael Neuling <mikey@neuling.org>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>
      0ea6e611
  17. 25 3月, 2010 1 次提交
  19. 24 2月, 2010 1 次提交
  21. 01 7月, 2009 1 次提交
  23. 30 3月, 2009 1 次提交
  25. 21 2月, 2009 1 次提交
  27. 16 1月, 2009 1 次提交
  29. 20 10月, 2008 1 次提交
  31. 14 9月, 2008 1 次提交
  33. 05 7月, 2008 2 次提交
  35. 19 6月, 2008 1 次提交
  37. 07 6月, 2008 1 次提交
  39. 29 4月, 2008 1 次提交
  41. 20 4月, 2008 1 次提交
  43. 24 2月, 2008 1 次提交
  45. 08 2月, 2008 1 次提交
  47. 20 10月, 2007 2 次提交
    • P
      cpuset sched_load_balance flag · 029190c5
      由 Paul Jackson 提交于 
      Add a new per-cpuset flag called 'sched_load_balance'.

When enabled in a cpuset (the default value) it tells the kernel scheduler
that the scheduler should provide the normal load balancing on the CPUs in
that cpuset, sometimes moving tasks from one CPU to a second CPU if the
second CPU is less loaded and if that task is allowed to run there.

When disabled (write "0" to the file) then it tells the kernel scheduler
that load balancing is not required for the CPUs in that cpuset.

Now even if this flag is disabled for some cpuset, the kernel may still
have to load balance some or all the CPUs in that cpuset, if some
overlapping cpuset has its sched_load_balance flag enabled.

If there are some CPUs that are not in any cpuset whose sched_load_balance
flag is enabled, the kernel scheduler will not load balance tasks to those
CPUs.

Moreover the kernel will partition the 'sched domains' (non-overlapping
sets of CPUs over which load balancing is attempted) into the finest
granularity partition that it can find, while still keeping any two CPUs
that are in the same shed_load_balance enabled cpuset in the same element
of the partition.

This serves two purposes:
 1) It provides a mechanism for real time isolation of some CPUs, and
 2) it can be used to improve performance on systems with many CPUs
    by supporting configurations in which load balancing is not done
    across all CPUs at once, but rather only done in several smaller
    disjoint sets of CPUs.

This mechanism replaces the earlier overloading of the per-cpuset
flag 'cpu_exclusive', which overloading was removed in an earlier
patch: cpuset-remove-sched-domain-hooks-from-cpusets

See further the Documentation and comments in the code itself.

[akpm@linux-foundation.org: don't be weird]
Signed-off-by: NPaul Jackson <pj@sgi.com>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      029190c5
    • P
      Task Control Groups: make cpusets a client of cgroups · 8793d854
      由 Paul Menage 提交于 
      Remove the filesystem support logic from the cpusets system and makes cpusets
a cgroup subsystem

The "cpuset" filesystem becomes a dummy filesystem; attempts to mount it get
passed through to the cgroup filesystem with the appropriate options to
emulate the old cpuset filesystem behaviour.
Signed-off-by: NPaul Menage <menage@google.com>
Cc: Serge E. Hallyn <serue@us.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Kirill Korotaev <dev@openvz.org>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      8793d854
  49. 17 10月, 2007 2 次提交
    • P
      cpuset: remove sched domain hooks from cpusets · 607717a6
      由 Paul Jackson 提交于 
      Remove the cpuset hooks that defined sched domains depending on the setting
of the 'cpu_exclusive' flag.

The cpu_exclusive flag can only be set on a child if it is set on the
parent.

This made that flag painfully unsuitable for use as a flag defining a
partitioning of a system.

It was entirely unobvious to a cpuset user what partitioning of sched
domains they would be causing when they set that one cpu_exclusive bit on
one cpuset, because it depended on what CPUs were in the remainder of that
cpusets siblings and child cpusets, after subtracting out other
cpu_exclusive cpusets.

Furthermore, there was no way on production systems to query the
result.

Using the cpu_exclusive flag for this was simply wrong from the get go.

Fortunately, it was sufficiently borked that so far as I know, almost no
successful use has been made of this.  One real time group did use it to
affectively isolate CPUs from any load balancing efforts.  They are willing
to adapt to alternative mechanisms for this, such as someway to manipulate
the list of isolated CPUs on a running system.  They can do without this
present cpu_exclusive based mechanism while we develop an alternative.

There is a real risk, to the best of my understanding, of users
accidentally setting up a partitioned scheduler domains, inhibiting desired
load balancing across all their CPUs, due to the nonobvious (from the
cpuset perspective) side affects of the cpu_exclusive flag.

Furthermore, since there was no way on a running system to see what one was
doing with sched domains, this change will be invisible to any using code.
Unless they have real insight to the scheduler load balancing choices, they
will be unable to detect that this change has been made in the kernel's
behaviour.

Initial discussion on lkml of this patch has generated much comment.  My
(probably controversial) take on that discussion is that it has reached a
rough concensus that the current cpuset cpu_exclusive mechanism for
defining sched domains is borked.  There is no concensus on the
replacement.  But since we can remove this mechanism, and since its
continued presence risks causing unwanted partitioning of the schedulers
load balancing, we should remove it while we can, as we proceed to work the
replacement scheduler domain mechanisms.
Signed-off-by: NPaul Jackson <pj@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Cc: Dinakar Guniguntala <dino@in.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      607717a6
    • C
      Memoryless nodes: Use N_HIGH_MEMORY for cpusets · 0e1e7c7a
      由 Christoph Lameter 提交于 
      cpusets try to ensure that any node added to a cpuset's mems_allowed is
on-line and contains memory.  The assumption was that online nodes contained
memory.  Thus, it is possible to add memoryless nodes to a cpuset and then add
tasks to this cpuset.  This results in continuous series of oom-kill and
apparent system hang.

Change cpusets to use node_states[N_HIGH_MEMORY] [a.k.a.  node_memory_map] in
place of node_online_map when vetting memories.  Return error if admin
attempts to write a non-empty mems_allowed node mask containing only
memoryless-nodes.
Signed-off-by: NLee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: NBob Picco <bob.picco@hp.com>
Signed-off-by: NNishanth Aravamudan <nacc@us.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@skynet.ie>
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      0e1e7c7a
  51. 03 4月, 2007 1 次提交
  53. 30 9月, 2006 1 次提交
    • P
      [PATCH] cpuset: top_cpuset tracks hotplug changes to node_online_map · 38837fc7
      由 Paul Jackson 提交于 
      Change the list of memory nodes allowed to tasks in the top (root) nodeset
to dynamically track what cpus are online, using a call to a cpuset hook
from the memory hotplug code.  Make this top cpus file read-only.

On systems that have cpusets configured in their kernel, but that aren't
actively using cpusets (for some distros, this covers the majority of
systems) all tasks end up in the top cpuset.

If that system does support memory hotplug, then these tasks cannot make
use of memory nodes that are added after system boot, because the memory
nodes are not allowed in the top cpuset.  This is a surprising regression
over earlier kernels that didn't have cpusets enabled.

One key motivation for this change is to remain consistent with the
behaviour for the top_cpuset's 'cpus', which is also read-only, and which
automatically tracks the cpu_online_map.

This change also has the minor benefit that it fixes a long standing,
little noticed, minor bug in cpusets.  The cpuset performance tweak to
short circuit the cpuset_zone_allowed() check on systems with just a single
cpuset (see 'number_of_cpusets', in linux/cpuset.h) meant that simply
changing the 'mems' of the top_cpuset had no affect, even though the change
(the write system call) appeared to succeed.  With the following change,
that write to the 'mems' file fails -EACCES, and the 'mems' file stubbornly
refuses to be changed via user space writes.  Thus no one should be mislead
into thinking they've changed the top_cpusets's 'mems' when in affect they
haven't.

In order to keep the behaviour of cpusets consistent between systems
actively making use of them and systems not using them, this patch changes
the behaviour of the 'mems' file in the top (root) cpuset, making it read
only, and making it automatically track the value of node_online_map.  Thus
tasks in the top cpuset will have automatic use of hot plugged memory nodes
allowed by their cpuset.

[akpm@osdl.org: build fix]
[bunk@stusta.de: build fix]
Signed-off-by: NPaul Jackson <pj@sgi.com>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      38837fc7
  55. 28 8月, 2006 1 次提交
    • P
      [PATCH] cpuset: top_cpuset tracks hotplug changes to cpu_online_map · 4c4d50f7
      由 Paul Jackson 提交于 
      Change the list of cpus allowed to tasks in the top (root) cpuset to
dynamically track what cpus are online, using a CPU hotplug notifier.  Make
this top cpus file read-only.

On systems that have cpusets configured in their kernel, but that aren't
actively using cpusets (for some distros, this covers the majority of
systems) all tasks end up in the top cpuset.

If that system does support CPU hotplug, then these tasks cannot make use
of CPUs that are added after system boot, because the CPUs are not allowed
in the top cpuset.  This is a surprising regression over earlier kernels
that didn't have cpusets enabled.

In order to keep the behaviour of cpusets consistent between systems
actively making use of them and systems not using them, this patch changes
the behaviour of the 'cpus' file in the top (root) cpuset, making it read
only, and making it automatically track the value of cpu_online_map.  Thus
tasks in the top cpuset will have automatic use of hot plugged CPUs allowed
by their cpuset.

Thanks to Anton Blanchard and Nathan Lynch for reporting this problem,
driving the fix, and earlier versions of this patch.
Signed-off-by: NPaul Jackson <pj@sgi.com>
Cc: Nathan Lynch <ntl@pobox.com>
Cc: Anton Blanchard <anton@samba.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      4c4d50f7
  57. 24 3月, 2006 1 次提交
    • P
      [PATCH] cpuset memory spread basic implementation · 825a46af
      由 Paul Jackson 提交于 
      This patch provides the implementation and cpuset interface for an alternative
memory allocation policy that can be applied to certain kinds of memory
allocations, such as the page cache (file system buffers) and some slab caches
(such as inode caches).

The policy is called "memory spreading." If enabled, it spreads out these
kinds of memory allocations over all the nodes allowed to a task, instead of
preferring to place them on the node where the task is executing.

All other kinds of allocations, including anonymous pages for a tasks stack
and data regions, are not affected by this policy choice, and continue to be
allocated preferring the node local to execution, as modified by the NUMA
mempolicy.

There are two boolean flag files per cpuset that control where the kernel
allocates pages for the file system buffers and related in kernel data
structures.  They are called 'memory_spread_page' and 'memory_spread_slab'.

If the per-cpuset boolean flag file 'memory_spread_page' is set, then the
kernel will spread the file system buffers (page cache) evenly over all the
nodes that the faulting task is allowed to use, instead of preferring to put
those pages on the node where the task is running.

If the per-cpuset boolean flag file 'memory_spread_slab' is set, then the
kernel will spread some file system related slab caches, such as for inodes
and dentries evenly over all the nodes that the faulting task is allowed to
use, instead of preferring to put those pages on the node where the task is
running.

The implementation is simple.  Setting the cpuset flags 'memory_spread_page'
or 'memory_spread_cache' turns on the per-process flags PF_SPREAD_PAGE or
PF_SPREAD_SLAB, respectively, for each task that is in the cpuset or
subsequently joins that cpuset.  In subsequent patches, the page allocation
calls for the affected page cache and slab caches are modified to perform an
inline check for these flags, and if set, a call to a new routine
cpuset_mem_spread_node() returns the node to prefer for the allocation.

The cpuset_mem_spread_node() routine is also simple.  It uses the value of a
per-task rotor cpuset_mem_spread_rotor to select the next node in the current
tasks mems_allowed to prefer for the allocation.

This policy can provide substantial improvements for jobs that need to place
thread local data on the corresponding node, but that need to access large
file system data sets that need to be spread across the several nodes in the
jobs cpuset in order to fit.  Without this patch, especially for jobs that
might have one thread reading in the data set, the memory allocation across
the nodes in the jobs cpuset can become very uneven.

A couple of Copyright year ranges are updated as well.  And a couple of email
addresses that can be found in the MAINTAINERS file are removed.
Signed-off-by: NPaul Jackson <pj@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      825a46af
  59. 15 3月, 2006 1 次提交
  61. 11 1月, 2006 1 次提交
  63. 09 1月, 2006 3 次提交
  65. 31 10月, 2005 1 次提交
  67. 11 9月, 2005 1 次提交
  69. 08 9月, 2005 1 次提交
    • P
      [PATCH] cpusets: formalize intermediate GFP_KERNEL containment · 9bf2229f
      由 Paul Jackson 提交于 
      This patch makes use of the previously underutilized cpuset flag
'mem_exclusive' to provide what amounts to another layer of memory placement
resolution.  With this patch, there are now the following four layers of
memory placement available:

 1) The whole system (interrupt and GFP_ATOMIC allocations can use this),
 2) The nearest enclosing mem_exclusive cpuset (GFP_KERNEL allocations can use),
 3) The current tasks cpuset (GFP_USER allocations constrained to here), and
 4) Specific node placement, using mbind and set_mempolicy.

These nest - each layer is a subset (same or within) of the previous.

Layer (2) above is new, with this patch.  The call used to check whether a
zone (its node, actually) is in a cpuset (in its mems_allowed, actually) is
extended to take a gfp_mask argument, and its logic is extended, in the case
that __GFP_HARDWALL is not set in the flag bits, to look up the cpuset
hierarchy for the nearest enclosing mem_exclusive cpuset, to determine if
placement is allowed.  The definition of GFP_USER, which used to be identical
to GFP_KERNEL, is changed to also set the __GFP_HARDWALL bit, in the previous
cpuset_gfp_hardwall_flag patch.

GFP_ATOMIC and GFP_KERNEL allocations will stay within the current tasks
cpuset, so long as any node therein is not too tight on memory, but will
escape to the larger layer, if need be.

The intended use is to allow something like a batch manager to handle several
jobs, each job in its own cpuset, but using common kernel memory for caches
and such.  Swapper and oom_kill activity is also constrained to Layer (2).  A
task in or below one mem_exclusive cpuset should not cause swapping on nodes
in another non-overlapping mem_exclusive cpuset, nor provoke oom_killing of a
task in another such cpuset.  Heavy use of kernel memory for i/o caching and
such by one job should not impact the memory available to jobs in other
non-overlapping mem_exclusive cpusets.

This patch enables providing hardwall, inescapable cpusets for memory
allocations of each job, while sharing kernel memory allocations between
several jobs, in an enclosing mem_exclusive cpuset.

Like Dinakar's patch earlier to enable administering sched domains using the
cpu_exclusive flag, this patch also provides a useful meaning to a cpuset flag
that had previously done nothing much useful other than restrict what cpuset
configurations were allowed.
Signed-off-by: NPaul Jackson <pj@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      9bf2229f