Chen noticed that cache_reap uses REAPTIMEOUT_CPUC+smp_processor_id() as
the timeout for rescheduling.
The "+smp_processor_id()" part is wrong, the timeout should be identical
for all cpus: start_cpu_timer already adds a cpu dependant offset to avoid
any clustering.
The attached patch removes smp_processor_id().
Signed-Off-By: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch renames struct kmem_cache_s to kmem_cache so we can start using
it instead of kmem_cache_t typedef.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
slab presently goes BUG if someone tries to register an already-registered
cache.
But this can happen if the user accidentally loads a module which is already
statically linked into the kernel. Nuking the kernel is rather a harsh
reaction.
Change it into a warning, and just fail the kmem_cache_alloc() attempt. If
the module is well-behaved, the modprobe will fail and all is well.
Notes:
- Swaps the ranking of cache_chain_sem and lock_cpu_hotplug(). Doesn't seem
important.
Acked-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Suppress split ptlock on arches which may use one page for multiple page
tables. Reconsider what better to do (particularly on ppc64) later on.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Adds a new CONFIG_PPC_64K_PAGES which, when enabled, changes the kernel
base page size to 64K. The resulting kernel still boots on any
hardware. On current machines with 4K pages support only, the kernel
will maintain 16 "subpages" for each 64K page transparently.
Note that while real 64K capable HW has been tested, the current patch
will not enable it yet as such hardware is not released yet, and I'm
still verifying with the firmware architects the proper to get the
information from the newer hypervisors.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch is a rewrite of the one submitted on October 1st, using modules
(http://marc.theaimsgroup.com/?l=linux-kernel&m=112819093522998&w=2).
This rewrite adds a tristate CONFIG_RCU_TORTURE_TEST, which enables an
intense torture test of the RCU infratructure. This is needed due to the
continued changes to the RCU infrastructure to accommodate dynamic ticks,
CPU hotplug, realtime, and so on. Most of the code is in a separate file
that is compiled only if the CONFIG variable is set. Documentation on how
to run the test and interpret the output is also included.
This code has been tested on i386 and ppc64, and an earlier version of the
code has received extensive testing on a number of architectures as part of
the PREEMPT_RT patchset.
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>
This patch removes redundant assignment from __pagevec_release_nonlru().
pages_to_free.cold is set to pvec->cold by pagevec_init() call right above
the assignment.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When __generic_file_aio_read() hits an error during reading, it reports the
error iff nothing has successfully been read yet. This is condition - when
an error occurs, if nothing has been read/written, report the error code;
otherwise, report the amount of bytes successfully transferred upto that
point.
This corner case can be exposed by performing readv(2) with the following
iov.
iov[0] = len0 @ ptr0
iov[1] = len1 @ NULL (or any other invalid pointer)
iov[2] = len2 @ ptr2
When file size is enough, performing above readv(2) results in
len0 bytes from file_pos @ ptr0
len2 bytes from file_pos + len0 @ ptr2
And the return value is len0 + len2. Test program is attached to this
mail.
This patch makes __generic_file_aio_read()'s error handling identical to
other functions.
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/uio.h>
#include <errno.h>
#include <string.h>
int main(int argc, char **argv)
{
const char *path;
struct stat stbuf;
size_t len0, len1;
void *buf0, *buf1;
struct iovec iov[3];
int fd, i;
ssize_t ret;
if (argc < 2) {
fprintf(stderr, "Usage: testreadv path (better be a "
"small text file)\n");
return 1;
}
path = argv[1];
if (stat(path, &stbuf) < 0) {
perror("stat");
return 1;
}
len0 = stbuf.st_size / 2;
len1 = stbuf.st_size - len0;
if (!len0 || !len1) {
fprintf(stderr, "Dude, file is too small\n");
return 1;
}
if ((fd = open(path, O_RDONLY)) < 0) {
perror("open");
return 1;
}
if (!(buf0 = malloc(len0)) || !(buf1 = malloc(len1))) {
perror("malloc");
return 1;
}
memset(buf0, 0, len0);
memset(buf1, 0, len1);
iov[0].iov_base = buf0;
iov[0].iov_len = len0;
iov[1].iov_base = NULL;
iov[1].iov_len = len1;
iov[2].iov_base = buf1;
iov[2].iov_len = len1;
printf("vector ");
for (i = 0; i < 3; i++)
printf("%p:%zu ", iov[i].iov_base, iov[i].iov_len);
printf("\n");
ret = readv(fd, iov, 3);
if (ret < 0)
perror("readv");
printf("readv returned %zd\nbuf0 = [%s]\nbuf1 = [%s]\n",
ret, (char *)buf0, (char *)buf1);
return 0;
}
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch automatically updates a tasks NUMA mempolicy when its cpuset
memory placement changes. It does so within the context of the task,
without any need to support low level external mempolicy manipulation.
If a system is not using cpusets, or if running on a system with just the
root (all-encompassing) cpuset, then this remap is a no-op. Only when a
task is moved between cpusets, or a cpusets memory placement is changed
does the following apply. Otherwise, the main routine below,
rebind_policy() is not even called.
When mixing cpusets, scheduler affinity, and NUMA mempolicies, the
essential role of cpusets is to place jobs (several related tasks) on a set
of CPUs and Memory Nodes, the essential role of sched_setaffinity is to
manage a jobs processor placement within its allowed cpuset, and the
essential role of NUMA mempolicy (mbind, set_mempolicy) is to manage a jobs
memory placement within its allowed cpuset.
However, CPU affinity and NUMA memory placement are managed within the
kernel using absolute system wide numbering, not cpuset relative numbering.
This is ok until a job is migrated to a different cpuset, or what's the
same, a jobs cpuset is moved to different CPUs and Memory Nodes.
Then the CPU affinity and NUMA memory placement of the tasks in the job
need to be updated, to preserve their cpuset-relative position. This can
be done for CPU affinity using sched_setaffinity() from user code, as one
task can modify anothers CPU affinity. This cannot be done from an
external task for NUMA memory placement, as that can only be modified in
the context of the task using it.
However, it easy enough to remap a tasks NUMA mempolicy automatically when
a task is migrated, using the existing cpuset mechanism to trigger a
refresh of a tasks memory placement after its cpuset has changed. All that
is needed is the old and new nodemask, and notice to the task that it needs
to rebind its mempolicy. The tasks mems_allowed has the old mask, the
tasks cpuset has the new mask, and the existing
cpuset_update_current_mems_allowed() mechanism provides the notice. The
bitmap/cpumask/nodemask remap operators provide the cpuset relative
calculations.
This patch leaves open a couple of issues:
1) Updating vma and shmfs/tmpfs/hugetlbfs memory policies:
These mempolicies may reference nodes outside of those allowed to
the current task by its cpuset. Tasks are migrated as part of jobs,
which reside on what might be several cpusets in a subtree. When such
a job is migrated, all NUMA memory policy references to nodes within
that cpuset subtree should be translated, and references to any nodes
outside that subtree should be left untouched. A future patch will
provide the cpuset mechanism needed to mark such subtrees. With that
patch, we will be able to correctly migrate these other memory policies
across a job migration.
2) Updating cpuset, affinity and memory policies in user space:
This is harder. Any placement state stored in user space using
system-wide numbering will be invalidated across a migration. More
work will be required to provide user code with a migration-safe means
to manage its cpuset relative placement, while preserving the current
API's that pass system wide numbers, not cpuset relative numbers across
the kernel-user boundary.
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 keeps pdflush daemons on the same cpuset as their parent, the
kthread daemon.
Some large NUMA configurations put as much as they can of kernel threads
and other classic Unix load in what's called a bootcpuset, keeping the rest
of the system free for dedicated jobs.
This effort is thwarted by pdflush, which dynamically destroys and
recreates pdflush daemons depending on load.
It's easy enough to force the originally created pdflush deamons into the
bootcpuset, at system boottime. But the pdflush threads created later were
allowed to run freely across the system, due to the necessary line in their
startup kthread():
set_cpus_allowed(current, CPU_MASK_ALL);
By simply coding pdflush to start its threads with the cpus_allowed
restrictions of its cpuset (inherited from kthread, its parent) we can
ensure that dynamically created pdflush threads are also kept in the
bootcpuset.
On systems w/o cpusets, or w/o a bootcpuset implementation, the following
will have no affect, leaving pdflush to run on any CPU, as before.
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix the problem (BUG 4964) with unmapped buffers in transaction's
t_sync_data list. The problem is we need to call filesystem's own
invalidatepage() from block_write_full_page().
block_write_full_page() must call filesystem's invalidatepage(). Otherwise
following nasty race can happen:
proc 1 proc 2
------ ------
- write some new data to 'offset'
=> bh gets to the transactions data list
- starts truncate
=> i_size set to new size
- mpage_writepages()
- ext3_ordered_writepage() to 'offset'
- block_write_full_page()
- page->index > end_index+1
- block_invalidatepage()
- discard_buffer()
- clear_buffer_mapped()
- commit triggers and finds unmapped buffer - BOOM!
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
move EXPORT_SYMBOL(filemap_populate) to the proper place: just after
function itself: it's easy to miss that function is exported otherwise.
Signed-off-by: Nikita Danilov <nikita@clusterfs.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In 'mm' change the explicit use of a for-loop using NR_CPUS into the
general for_each_cpu() constructs. This widens the scope of potential
future optimizations of the general constructs, as well as takes advantage
of the existing optimizations of first_cpu() and next_cpu(), which is
advantageous when the true CPU count is much smaller than NR_CPUS.
Signed-off-by: John Hawkes <hawkes@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Policy contextualization is only useful for task based policies and not for
vma based policies. It may be useful to define allowed nodes that are not
accessible from this thread because other threads may have access to these
nodes. Without this patch strange memory policy situations may cause an
application to fail with out of memory.
Example:
Let's say we have two threads A and B that share the same address space and
a huge array computational array X.
Thread A is restricted by its cpuset to nodes 0 and 1 and thread B is
restricted by its cpuset to nodes 2 and 3.
Thread A now wants to restrict allocations to the first node and thus
applies a BIND policy on X to node 0 and 2. The cpuset limits this to node
0. Thus pages for X must be allocated on node 0 now.
Thread B now touches a page that has never been used in X and faults in a
page. According to the BIND policy of the vma for X the page must be
allocated on page 0. However, the cpuset of B does not allow allocation on
0 and 1. Now the application fails in alloc_pages with out of memory.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- Do a separation between do_xxx and sys_xxx functions. sys_xxx functions
take variable sized bitmaps from user space as arguments. do_xxx functions
take fixed sized nodemask_t as arguments and may be used from inside the
kernel. Doing so simplifies the initialization code. There is no
fs = kernel_ds assumption anymore.
- Split up get_nodes into get_nodes (which gets the node list) and
contextualize_policy which restricts the nodes to those accessible
to the task and updates cpusets.
- Add comments explaining limitations of bind policy
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
From: IWAMOTO Toshihiro <iwamoto@valinux.co.jp>
> I found the tests does not work well with Dave's patchset.
> I've found the followings:
>
> - setup_per_zone_pages_min() calls should be added in
> capture_page_range() and online_pages()
> - lru_add_drain() should be called before try_to_migrate_pages()
The following patch deals with the first item.
Signed-off-by: IWAMOTO Toshihiro <iwamoto@valinux.co.jp>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This basically keeps up from having to extern __kmalloc_section_memmap().
The vaddr_in_vmalloc_area() helper could go in a vmalloc header, but that
header gets hard to work with, because it needs some arch-specific macros.
Just stick it in here for now, instead of creating another header.
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Lion Vollnhals <webmaster@schiggl.de>
Signed-off-by: Jiri Slaby <xslaby@fi.muni.cz>
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This adds generic memory add/remove and supporting functions for memory
hotplug into a new file as well as a memory hotplug kernel config option.
Individual architecture patches will follow.
For now, disable memory hotplug when swsusp is enabled. There's a lot of
churn there right now. We'll fix it up properly once it calms down.
Signed-off-by: Matt Tolentino <matthew.e.tolentino@intel.com>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
See the "fixup bad_range()" patch for more information, but this actually
creates a the lock to protect things making assumptions about a zone's size
staying constant at runtime.
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
pgdat->node_size_lock is basically only neeeded in one place in the normal
code: show_mem(), which is the arch-specific sysrq-m printing function.
Strictly speaking, the architectures not doing memory hotplug do no need this
locking in show_mem(). However, they are all included for completeness. This
should also make any future consolidation of all of the implementations a
little more straightforward.
This lock is also held in the sparsemem code during a memory removal, as
sections are invalidated. This is the place there pfn_valid() is made false
for a memory area that's being removed. The lock is only required when doing
pfn_valid() operations on memory which the user does not already have a
reference on the page, such as in show_mem().
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When doing memory hotplug operations, the size of existing zones can obviously
change. This means that zone->zone_{start_pfn,spanned_pages} can change.
There are currently no locks that protect these structure members. However,
they are rarely accessed at runtime. Outside of swsusp, the only place that I
can find is bad_range().
So, split bad_range() up into two pieces: one that needs to be locked and
anther that doesn't.
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
If a zone is empty at boot-time and then hot-added to later, it needs to run
the same init code that would have been run on it at boot.
This patch breaks out zone table and per-cpu-pages functions for use by the
hotplug code. You can almost see all of the free_area_init_core() function on
one page now. :)
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
