Remove a useless variable initialization in cpuset __cpuset_zone_allowed().
The local variable 'allowed' is unconditionally set before use, later on
in the code, so does not need to be initialized.
Not that it seems to matter to the code generated any, as the compiler
optimizes out the superfluous assignment anyway.
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The hook in the slab cache allocation path to handle cpuset memory
spreading for tasks in cpusets with 'memory_spread_slab' enabled has a
modest performance bug. The hook calls into the memory spreading handler
alternate_node_alloc() if either of 'memory_spread_slab' or
'memory_spread_page' is enabled, even though the handler does nothing
(albeit harmlessly) for the page case
Fix - drop PF_SPREAD_PAGE from the set of flag bits that are used to
trigger a call to alternate_node_alloc().
The page case is handled by separate hooks -- see the calls conditioned on
cpuset_do_page_mem_spread() in mm/filemap.c
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Drop the atomic_t marking on the cpuset static global
cpuset_mems_generation. Since all access to it is guarded by the global
manage_mutex, there is no need for further serialization of this value.
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Remove a no longer needed test for NULL cpuset pointer, with a little
comment explaining why the test isn't needed.
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Change the kmem_cache_create calls for certain slab caches to support cpuset
memory spreading.
See the previous patches, cpuset_mem_spread, for an explanation of cpuset
memory spreading, and cpuset_mem_spread_slab_cache for the slab cache support
for memory spreading.
The slab caches marked for now are: dentry_cache, inode_cache, some xfs slab
caches, and buffer_head. This list may change over time. In particular,
other file system types that are used extensively on large NUMA systems may
want to allow for spreading their directory and inode slab cache entries.
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The hooks in the slab cache allocator code path for support of NUMA
mempolicies and cpuset memory spreading are in an important code path. Many
systems will use neither feature.
This patch optimizes those hooks down to a single check of some bits in the
current tasks task_struct flags. For non NUMA systems, this hook and related
code is already ifdef'd out.
The optimization is done by using another task flag, set if the task is using
a non-default NUMA mempolicy. Taking this flag bit along with the
PF_SPREAD_PAGE and PF_SPREAD_SLAB flag bits added earlier in this 'cpuset
memory spreading' patch set, one can check for the combination of any of these
special case memory placement mechanisms with a single test of the current
tasks task_struct flags.
This patch also tightens up the code, to save a few bytes of kernel text
space, and moves some of it out of line. Due to the nested inlines called
from multiple places, we were ending up with three copies of this code, which
once we get off the main code path (for local node allocation) seems a bit
wasteful of instruction memory.
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Provide the slab cache infrastructure to support cpuset memory spreading.
See the previous patches, cpuset_mem_spread, for an explanation of cpuset
memory spreading.
This patch provides a slab cache SLAB_MEM_SPREAD flag. If set in the
kmem_cache_create() call defining a slab cache, then any task marked with the
process state flag PF_MEMSPREAD will spread memory page allocations for that
cache over all the allowed nodes, instead of preferring the local (faulting)
node.
On systems not configured with CONFIG_NUMA, this results in no change to the
page allocation code path for slab caches.
On systems with cpusets configured in the kernel, but the "memory_spread"
cpuset option not enabled for the current tasks cpuset, this adds a call to a
cpuset routine and failed bit test of the processor state flag PF_SPREAD_SLAB.
For tasks so marked, a second inline test is done for the slab cache flag
SLAB_MEM_SPREAD, and if that is set and if the allocation is not
in_interrupt(), this adds a call to to a cpuset routine that computes which of
the tasks mems_allowed nodes should be preferred for this allocation.
==> This patch adds another hook into the performance critical
code path to allocating objects from the slab cache, in the
____cache_alloc() chunk, below. The next patch optimizes this
hook, reducing the impact of the combined mempolicy plus memory
spreading hooks on this critical code path to a single check
against the tasks task_struct flags word.
This patch provides the generic slab flags and logic needed to apply memory
spreading to a particular slab.
A subsequent patch will mark a few specific slab caches for this placement
policy.
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Rewrap the overly long source code lines resulting from the previous
patch's addition of the slab cache flag SLAB_MEM_SPREAD. This patch
contains only formatting changes, and no function change.
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Mark file system inode and similar slab caches subject to SLAB_MEM_SPREAD
memory spreading.
If a slab cache is marked SLAB_MEM_SPREAD, then anytime that a task that's
in a cpuset with the 'memory_spread_slab' option enabled goes to allocate
from such a slab cache, the allocations are spread evenly over all the
memory nodes (task->mems_allowed) allowed to that task, instead of favoring
allocation on the node local to the current cpu.
The following inode and similar caches are marked SLAB_MEM_SPREAD:
file cache
==== =====
fs/adfs/super.c adfs_inode_cache
fs/affs/super.c affs_inode_cache
fs/befs/linuxvfs.c befs_inode_cache
fs/bfs/inode.c bfs_inode_cache
fs/block_dev.c bdev_cache
fs/cifs/cifsfs.c cifs_inode_cache
fs/coda/inode.c coda_inode_cache
fs/dquot.c dquot
fs/efs/super.c efs_inode_cache
fs/ext2/super.c ext2_inode_cache
fs/ext2/xattr.c (fs/mbcache.c) ext2_xattr
fs/ext3/super.c ext3_inode_cache
fs/ext3/xattr.c (fs/mbcache.c) ext3_xattr
fs/fat/cache.c fat_cache
fs/fat/inode.c fat_inode_cache
fs/freevxfs/vxfs_super.c vxfs_inode
fs/hpfs/super.c hpfs_inode_cache
fs/isofs/inode.c isofs_inode_cache
fs/jffs/inode-v23.c jffs_fm
fs/jffs2/super.c jffs2_i
fs/jfs/super.c jfs_ip
fs/minix/inode.c minix_inode_cache
fs/ncpfs/inode.c ncp_inode_cache
fs/nfs/direct.c nfs_direct_cache
fs/nfs/inode.c nfs_inode_cache
fs/ntfs/super.c ntfs_big_inode_cache_name
fs/ntfs/super.c ntfs_inode_cache
fs/ocfs2/dlm/dlmfs.c dlmfs_inode_cache
fs/ocfs2/super.c ocfs2_inode_cache
fs/proc/inode.c proc_inode_cache
fs/qnx4/inode.c qnx4_inode_cache
fs/reiserfs/super.c reiser_inode_cache
fs/romfs/inode.c romfs_inode_cache
fs/smbfs/inode.c smb_inode_cache
fs/sysv/inode.c sysv_inode_cache
fs/udf/super.c udf_inode_cache
fs/ufs/super.c ufs_inode_cache
net/socket.c sock_inode_cache
net/sunrpc/rpc_pipe.c rpc_inode_cache
The choice of which slab caches to so mark was quite simple. I marked
those already marked SLAB_RECLAIM_ACCOUNT, except for fs/xfs, dentry_cache,
inode_cache, and buffer_head, which were marked in a previous patch. Even
though SLAB_RECLAIM_ACCOUNT is for a different purpose, it marks the same
potentially large file system i/o related slab caches as we need for memory
spreading.
Given that the rule now becomes "wherever you would have used a
SLAB_RECLAIM_ACCOUNT slab cache flag before (usually the inode cache), use
the SLAB_MEM_SPREAD flag too", this should be easy enough to maintain.
Future file system writers will just copy one of the existing file system
slab cache setups and tend to get it right without thinking.
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Change the page cache allocation calls to support cpuset memory spreading.
See the previous patch, cpuset_mem_spread, for an explanation of cpuset memory
spreading.
On systems without cpusets configured in the kernel, this is no change.
On systems with cpusets configured in the kernel, but the "memory_spread"
cpuset option not enabled for the current tasks cpuset, this adds a call to a
cpuset routine and failed bit test of the processor state flag PF_SPREAD_PAGE.
On tasks in cpusets with "memory_spread" enabled, this adds a call to a cpuset
routine that computes which of the tasks mems_allowed nodes should be
preferred for this allocation.
If memory spreading applies to a particular allocation, then any other NUMA
mempolicy does not apply.
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Replace pairs of calls to <atomic_inc, atomic_read>, with a single call
atomic_inc_return, saving a few bytes of source and kernel text.
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Since the test_bit() bit operator is boolean (return 0 or 1), the double not
"!!" operations needed to convert a scalar (zero or not zero) to a boolean are
not needed.
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
If we get under some memory pressure in a cpuset (we only scan zones that
are in the cpuset for memory) then kswapd is woken up for all zones. This
patch only wakes up kswapd in zones that are part of the current cpuset.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Acked-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
A long-running rcutorture test can overflow dmesg, so that the line
containing the module parameters is lost. Although it is usually possible
to retrieve this information from the log files, it is much better to just
tag it onto the final success/failure line so that it may be easily found.
This patch does just that.
Signed-off-by: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
include/linux/platform.h contained nothing that was actually used except
the default_idle() prototype, and is therefore removed by this patch.
This patch does the following with the platform specific default_idle()
functions on different architectures:
- remove the unused function:
- parisc
- sparc64
- make the needlessly global function static:
- arm
- h8300
- m68k
- m68knommu
- s390
- v850
- x86_64
- add a prototype in asm/system.h:
- cris
- i386
- ia64
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Patrick Mochel <mochel@digitalimplant.org>
Acked-by: Kyle McMartin <kyle@parisc-linux.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
With internal Xen-enabled kernels we see the kernel's static per-cpu data
area exceed the limit of 32k on x86-64, and even native x86-64 kernels get
fairly close to that limit. I generally question whether it is reasonable
to have data structures several kb in size allocated as per-cpu data when
the space there is rather limited.
The biggest arch-independent consumer is tvec_bases (over 4k on 32-bit
archs, over 8k on 64-bit ones), which now gets converted to use dynamically
allocated memory instead.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Introduce a file fs/coda/coda_int.h with proper prototypes for some code.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add a proper prototype for ext2_get_parent().
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- mux.c: v9fs_poll_mux() was inline but not static resuling in needless
object size bloat
- mux.c: remove all "inline"s: gcc should know best what to inline
- #if 0 the following unused global functions:
- 9p.c: v9fs_v9fs_t_flush()
- conv.c: v9fs_create_tauth()
- mux.c: v9fs_mux_rpcnb()
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Eric Van Hensbergen <ericvh@ericvh.myip.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
__rcu_process_callbacks() disables interrupts to protect itself from
call_rcu() which adds new entries to ->nxtlist.
However we can check "->nxtlist != NULL" with interrupts enabled, we can't
get "false positives" because call_rcu() can only change this condition
from 0 to 1.
Tested with rcutorture.ko.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Dipankar Sarma <dipankar@in.ibm.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
