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  1. 23 Jun, 2006 2 commits
  3. 20 Jun, 2006 1 commit
  5. 24 Mar, 2006 3 commits
  7. 08 Mar, 2006 1 commit
    • Dipankar Sarma's avatar
      [PATCH] fix file counting · 529bf6be
      Dipankar Sarma authored 
      
I have benchmarked this on an x86_64 NUMA system and see no significant
performance difference on kernbench.  Tested on both x86_64 and powerpc.

The way we do file struct accounting is not very suitable for batched
freeing.  For scalability reasons, file accounting was
constructor/destructor based.  This meant that nr_files was decremented
only when the object was removed from the slab cache.  This is susceptible
to slab fragmentation.  With RCU based file structure, consequent batched
freeing and a test program like Serge's, we just speed this up and end up
with a very fragmented slab -

llm22:~ # cat /proc/sys/fs/file-nr
587730  0       758844

At the same time, I see only a 2000+ objects in filp cache.  The following
patch I fixes this problem.

This patch changes the file counting by removing the filp_count_lock.
Instead we use a separate percpu counter, nr_files, for now and all
accesses to it are through get_nr_files() api.  In the sysctl handler for
nr_files, we populate files_stat.nr_files before returning to user.

Counting files as an when they are created and destroyed (as opposed to
inside slab) allows us to correctly count open files with RCU.
Signed-off-by: default avatarDipankar Sarma <dipankar@in.ibm.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      529bf6be
  9. 02 Mar, 2006 1 commit
  11. 28 Feb, 2006 1 commit
  13. 20 Feb, 2006 2 commits
  15. 17 Feb, 2006 1 commit
  17. 01 Feb, 2006 2 commits
  19. 18 Jan, 2006 1 commit
  21. 14 Jan, 2006 1 commit
  23. 11 Jan, 2006 1 commit
  25. 08 Jan, 2006 2 commits
    • Rohit Seth's avatar
      [PATCH] Make high and batch sizes of per_cpu_pagelists configurable · 8ad4b1fb
      Rohit Seth authored 
      
As recently there has been lot of traffic on the right values for batch and
high water marks for per_cpu_pagelists.  This patch makes these two
variables configurable through /proc interface.

A new tunable /proc/sys/vm/percpu_pagelist_fraction is added.  This entry
controls the fraction of pages at most in each zone that are allocated for
each per cpu page list.  The min value for this is 8.  It means that we
don't allow more than 1/8th of pages in each zone to be allocated in any
single per_cpu_pagelist.

The batch value of each per cpu pagelist is also updated as a result.  It
is set to pcp->high/4.  The upper limit of batch is (PAGE_SHIFT * 8)
Signed-off-by: default avatarRohit Seth <rohit.seth@intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      8ad4b1fb
    • Andrew Morton's avatar
      [PATCH] drop-pagecache · 9d0243bc
      Andrew Morton authored 
      
Add /proc/sys/vm/drop_caches.  When written to, this will cause the kernel to
discard as much pagecache and/or reclaimable slab objects as it can.  THis
operation requires root permissions.

It won't drop dirty data, so the user should run `sync' first.

Caveats:

a) Holds inode_lock for exorbitant amounts of time.

b) Needs to be taught about NUMA nodes: propagate these all the way through
   so the discarding can be controlled on a per-node basis.

This is a debugging feature: useful for getting consistent results between
filesystem benchmarks.  We could possibly put it under a config option, but
it's less than 300 bytes.
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      9d0243bc
  27. 06 Jan, 2006 1 commit
  29. 04 Jan, 2006 2 commits
  31. 31 Dec, 2005 1 commit
  33. 30 Dec, 2005 2 commits
    • Yi Yang's avatar
      [PATCH] Fix false old value return of sysctl · 82c9df82
      Yi Yang authored 
      
For the sysctl syscall, if the user wants to get the old value of a
sysctl entry and set a new value for it in the same syscall, the old
value is always overwritten by the new value if the sysctl entry is of
string type and if the user sets its strategy to sysctl_string.  This
issue lies in the strategy being run twice if the strategy is set to
sysctl_string, the general strategy sysctl_string always returns 0 if
success.

Such strategy routines as sysctl_jiffies and sysctl_jiffies_ms return 1
because they do read and write for the sysctl entry.

The strategy routine sysctl_string return 0 although it actually read
and write the sysctl entry.

According to my analysis, if a strategy routine do read and write, it
should return 1, if it just does some necessary check but not read and
write, it should return 0, for example sysctl_intvec.
Signed-off-by: default avatarYi Yang <yang.y.yi@gmail.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      82c9df82
    • Linus Torvalds's avatar
      sysctl: don't overflow the user-supplied buffer with '\0' · 8febdd85
      Linus Torvalds authored 
      
If the string was too long to fit in the user-supplied buffer,
the sysctl layer would zero-terminate it by writing past the
end of the buffer. Don't do that.

Noticed by Yi Yang <yang.y.yi@gmail.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      8febdd85
  35. 08 Nov, 2005 1 commit
    • Al Viro's avatar
      [PATCH] Fix sysctl unregistration oops (CVE-2005-2709) · 330d57fb
      Al Viro authored 
      
You could open the /proc/sys/net/ipv4/conf/<if>/<whatever> file, then
wait for interface to go away, try to grab as much memory as possible in
hope to hit the (kfreed) ctl_table.  Then fill it with pointers to your
function.  Then do read from file you've opened and if you are lucky,
you'll get it called as ->proc_handler() in kernel mode.

So this is at least an Oops and possibly more.  It does depend on an
interface going away though, so less of a security risk than it would
otherwise be.
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      330d57fb
  37. 07 Nov, 2005 2 commits
    • Randy Dunlap's avatar
      [PATCH] more kernel-doc cleanups, additions · 1e5d5331
      Randy Dunlap authored 
      
Various core kernel-doc cleanups:
- add missing function parameters in ipc, irq/manage, kernel/sys,
  kernel/sysctl, and mm/slab;
- move description to just above function for kernel_restart()
Signed-off-by: default avatarRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      1e5d5331
    • Zach Brown's avatar
      [PATCH] aio: remove aio_max_nr accounting race · d55b5fda
      Zach Brown authored 
      
AIO was adding a new context's max requests to the global total before
testing if that resulting total was over the global limit.  This let
innocent tasks get their new limit tested along with a racing guilty task
that was crossing the limit.  This serializes the _nr accounting with a
spinlock It also switches to using unsigned long for the global totals.
Individual contexts are still limited to an unsigned int's worth of
requests by the syscall interface.

The problem and fix were verified with a simple program that spun creating
and destroying a context while holding on to another long lived context.
Before the patch a task creating a tiny context could get a spurious EAGAIN
if it raced with a task creating a very large context that overran the
limit.
Signed-off-by: default avatarZach Brown <zach.brown@oracle.com>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      d55b5fda
  39. 29 Aug, 2005 1 commit
  41. 27 Jul, 2005 1 commit
    • Martin Schwidefsky's avatar
      [PATCH] s390: spin lock retry · 951f22d5
      Martin Schwidefsky authored 
      
Split spin lock and r/w lock implementation into a single try which is done
inline and an out of line function that repeatedly tries to get the lock
before doing the cpu_relax().  Add a system control to set the number of
retries before a cpu is yielded.

The reason for the spin lock retry is that the diagnose 0x44 that is used to
give up the virtual cpu is quite expensive.  For spin locks that are held only
for a short period of time the costs of the diagnoses outweights the savings
for spin locks that are held for a longer timer.  The default retry count is
1000.
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      951f22d5
  43. 13 Jul, 2005 1 commit
  45. 12 Jul, 2005 1 commit
    • Robert Love's avatar
      [PATCH] inotify · 0eeca283
      Robert Love authored 
      
inotify is intended to correct the deficiencies of dnotify, particularly
its inability to scale and its terrible user interface:

        * dnotify requires the opening of one fd per each directory
          that you intend to watch. This quickly results in too many
          open files and pins removable media, preventing unmount.
        * dnotify is directory-based. You only learn about changes to
          directories. Sure, a change to a file in a directory affects
          the directory, but you are then forced to keep a cache of
          stat structures.
        * dnotify's interface to user-space is awful.  Signals?

inotify provides a more usable, simple, powerful solution to file change
notification:

        * inotify's interface is a system call that returns a fd, not SIGIO.
	  You get a single fd, which is select()-able.
        * inotify has an event that says "the filesystem that the item
          you were watching is on was unmounted."
        * inotify can watch directories or files.

Inotify is currently used by Beagle (a desktop search infrastructure),
Gamin (a FAM replacement), and other projects.

See Documentation/filesystems/inotify.txt.
Signed-off-by: default avatarRobert Love <rml@novell.com>
Cc: John McCutchan <ttb@tentacle.dhs.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      0eeca283
  47. 25 Jun, 2005 1 commit
  49. 23 Jun, 2005 1 commit
    • Alan Cox's avatar
      [PATCH] setuid core dump · d6e71144
      Alan Cox authored 
      
Add a new `suid_dumpable' sysctl:

This value can be used to query and set the core dump mode for setuid
or otherwise protected/tainted binaries. The modes are

0 - (default) - traditional behaviour.  Any process which has changed
    privilege levels or is execute only will not be dumped

1 - (debug) - all processes dump core when possible.  The core dump is
    owned by the current user and no security is applied.  This is intended
    for system debugging situations only.  Ptrace is unchecked.

2 - (suidsafe) - any binary which normally would not be dumped is dumped
    readable by root only.  This allows the end user to remove such a dump but
    not access it directly.  For security reasons core dumps in this mode will
    not overwrite one another or other files.  This mode is appropriate when
    adminstrators are attempting to debug problems in a normal environment.

(akpm:

> > +EXPORT_SYMBOL(suid_dumpable);
>
> EXPORT_SYMBOL_GPL?

No problem to me.

> >  	if (current->euid == current->uid && current->egid == current->gid)
> >  		current->mm->dumpable = 1;
>
> Should this be SUID_DUMP_USER?

Actually the feedback I had from last time was that the SUID_ defines
should go because its clearer to follow the numbers. They can go
everywhere (and there are lots of places where dumpable is tested/used
as a bool in untouched code)

> Maybe this should be renamed to `dump_policy' or something.  Doing that
> would help us catch any code which isn't using the #defines, too.

Fair comment. The patch was designed to be easy to maintain for Red Hat
rather than for merging. Changing that field would create a gigantic
diff because it is used all over the place.

)
Signed-off-by: default avatarAlan Cox <alan@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      d6e71144
  51. 01 May, 2005 1 commit
  53. 16 Apr, 2005 1 commit
    • Linus Torvalds's avatar
      Linux-2.6.12-rc2 · 1da177e4
      Linus Torvalds authored 
      Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
      1da177e4