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  1. 07 11月, 2005 15 次提交
  3. 02 11月, 2005 1 次提交
  5. 31 10月, 2005 7 次提交
    • M
      [PATCH] Error checks omitted in init_tmpfs() in mm/tiny-shmem.c · 5d57bd39
      由 Matt Mackall 提交于 
      From: Hareesh Nagarajan <hnagar2@gmail.com>
Signed-off-by: NHareesh Nagarajan <hnagar2@gmail.com>
Acked-by: NMatt Mackall <mpm@selenic.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      5d57bd39
    • P
      [PATCH] RCU torture-testing kernel module · a241ec65
      由 Paul E. McKenney 提交于 
      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: N"Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      a241ec65
    • T
      [PATCH] vm: remove redundant assignment from __pagevec_release_nonlru() · c7e9dd4d
      由 Tejun Heo 提交于 
      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: NTejun Heo <htejun@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      c7e9dd4d
    • T
      [PATCH] fs: error case fix in __generic_file_aio_read · 39e88ca2
      由 Tejun Heo 提交于 
      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: NTejun Heo <htejun@gmail.com>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      39e88ca2
    • P
      [PATCH] cpusets: automatic numa mempolicy rebinding · 68860ec1
      由 Paul Jackson 提交于 
      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: NPaul Jackson <pj@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      68860ec1
    • P
      [PATCH] cpusets: confine pdflush to its cpuset · 28a42b9e
      由 Paul Jackson 提交于 
      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: NPaul Jackson <pj@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      28a42b9e
    • J
      [PATCH] ext3: Fix unmapped buffers in transaction's lists · aaa4059b
      由 Jan Kara 提交于 
      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: NJan Kara <jack@suse.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      aaa4059b
  7. 30 10月, 2005 17 次提交