linux.git/include/linux, branch v2.6.23

mm: set_page_dirty_balance() vs ->page_mkwrite()

2007-10-08T19:58:14+00:00

All the current page_mkwrite() implementations also set the page dirty. Which
results in the set_page_dirty_balance() call to _not_ call balance, because the
page is already found dirty.

This allows us to dirty a _lot_ of pages without ever hitting
balance_dirty_pages().  Not good (tm).

Force a balance call if ->page_mkwrite() was successful.

Signed-off-by: Peter Zijlstra 
Signed-off-by: Linus Torvalds

Don't do load-average calculations at even 5-second intervals

2007-10-07T23:23:13+00:00

It turns out that there are a few other five-second timers in the
kernel, and if the timers get in sync, the load-average can get
artificially inflated by events that just happen to coincide.

So just offset the load average calculation it by a timer tick.

Noticed by Anders Boström, for whom the coincidence started triggering
on one of his machines with the JBD jiffies rounding code (JBD is one of
the subsystems that also end up using a 5-second timer by default).

Tested-by: Anders Boström 
Cc: Chuck Ebbert 
Cc: Arjan van de Ven 
Cc: Andrew Morton 
Signed-off-by: Linus Torvalds

Revert "[PATCH] x86-64: fix x86_64-mm-sched-clock-share"

2007-09-26T22:52:17+00:00

This reverts commit 184c44d2049c4db7ef6ec65794546954da2c6a0e.

As noted by Dave Jones:
   "Linus, please revert the above cset.  It doesn't seem to be
    necessary (it was added to fix a miscompile in 'make allnoconfig'
    which doesn't seem to be repeatable with it reverted) and actively
   breaks the ARM SA1100 framebuffer driver."

Requested-by: Dave Jones 
Cc: Russell King 
Cc: Andrew Morton 
Cc: Andi Kleen 
Signed-off-by: Linus Torvalds

signalfd simplification

2007-09-20T20:19:59+00:00

This simplifies signalfd code, by avoiding it to remain attached to the
sighand during its lifetime.

In this way, the signalfd remain attached to the sighand only during
poll(2) (and select and epoll) and read(2).  This also allows to remove
all the custom "tsk == current" checks in kernel/signal.c, since
dequeue_signal() will only be called by "current".

I think this is also what Ben was suggesting time ago.

The external effect of this, is that a thread can extract only its own
private signals and the group ones.  I think this is an acceptable
behaviour, in that those are the signals the thread would be able to
fetch w/out signalfd.

Signed-off-by: Davide Libenzi 
Signed-off-by: Linus Torvalds

sched: add /proc/sys/kernel/sched_compat_yield

2007-09-19T21:34:46+00:00

add /proc/sys/kernel/sched_compat_yield to make sys_sched_yield()
more agressive, by moving the yielding task to the last position
in the rbtree.

with sched_compat_yield=0:

   PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
  2539 mingo     20   0  1576  252  204 R   50  0.0   0:02.03 loop_yield
  2541 mingo     20   0  1576  244  196 R   50  0.0   0:02.05 loop

with sched_compat_yield=1:

   PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
  2584 mingo     20   0  1576  248  196 R   99  0.0   0:52.45 loop
  2582 mingo     20   0  1576  256  204 R    0  0.0   0:00.00 loop_yield

Signed-off-by: Ingo Molnar 
Signed-off-by: Peter Zijlstra

Fix NUMA Memory Policy Reference Counting

2007-09-19T18:24:18+00:00

This patch proposes fixes to the reference counting of memory policy in the
page allocation paths and in show_numa_map().  Extracted from my "Memory
Policy Cleanups and Enhancements" series as stand-alone.

Shared policy lookup [shmem] has always added a reference to the policy,
but this was never unrefed after page allocation or after formatting the
numa map data.

Default system policy should not require additional ref counting, nor
should the current task's task policy.  However, show_numa_map() calls
get_vma_policy() to examine what may be [likely is] another task's policy.
The latter case needs protection against freeing of the policy.

This patch adds a reference count to a mempolicy returned by
get_vma_policy() when the policy is a vma policy or another task's
mempolicy.  Again, shared policy is already reference counted on lookup.  A
matching "unref" [__mpol_free()] is performed in alloc_page_vma() for
shared and vma policies, and in show_numa_map() for shared and another
task's mempolicy.  We can call __mpol_free() directly, saving an admittedly
inexpensive inline NULL test, because we know we have a non-NULL policy.

Handling policy ref counts for hugepages is a bit trickier.
huge_zonelist() returns a zone list that might come from a shared or vma
'BIND policy.  In this case, we should hold the reference until after the
huge page allocation in dequeue_hugepage().  The patch modifies
huge_zonelist() to return a pointer to the mempolicy if it needs to be
unref'd after allocation.

Kernel Build [16cpu, 32GB, ia64] - average of 10 runs:

		w/o patch	w/ refcount patch
	    Avg	  Std Devn	   Avg	  Std Devn
Real:	 100.59	    0.38	 100.63	    0.43
User:	1209.60	    0.37	1209.91	    0.31
System:   81.52	    0.42	  81.64	    0.34

Signed-off-by:  Lee Schermerhorn 
Acked-by: Andi Kleen 
Cc: Christoph Lameter 
Acked-by: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Fix user namespace exiting OOPs

2007-09-19T18:24:18+00:00

It turned out, that the user namespace is released during the do_exit() in
exit_task_namespaces(), but the struct user_struct is released only during the
put_task_struct(), i.e.  MUCH later.

On debug kernels with poisoned slabs this will cause the oops in
uid_hash_remove() because the head of the chain, which resides inside the
struct user_namespace, will be already freed and poisoned.

Since the uid hash itself is required only when someone can search it, i.e.
when the namespace is alive, we can safely unhash all the user_struct-s from
it during the namespace exiting.  The subsequent free_uid() will complete the
user_struct destruction.

For example simple program

   #include 

   char stack[2 * 1024 * 1024];

   int f(void *foo)
   {
   	return 0;
   }

   int main(void)
   {
   	clone(f, stack + 1 * 1024 * 1024, 0x10000000, 0);
   	return 0;
   }

run on kernel with CONFIG_USER_NS turned on will oops the
kernel immediately.

This was spotted during OpenVZ kernel testing.

Signed-off-by: Pavel Emelyanov 
Signed-off-by: Alexey Dobriyan 
Acked-by: "Serge E. Hallyn" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Convert uid hash to hlist

2007-09-19T18:24:18+00:00

Surprisingly, but (spotted by Alexey Dobriyan) the uid hash still uses
list_heads, thus occupying twice as much place as it could.  Convert it to
hlist_heads.

Signed-off-by: Pavel Emelyanov 
Signed-off-by: Alexey Dobriyan 
Acked-by: Serge Hallyn 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6

2007-09-17T04:14:54+00:00

* 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6:
  [VLAN]: Fix net_device leak.
  [PPP] generic: Fix receive path data clobbering & non-linear handling
  [PPP] generic: Call skb_cow_head before scribbling over skb
  [NET] skbuff: Add skb_cow_head
  [BRIDGE]: Kill clone argument to br_flood_*
  [PPP] pppoe: Fill in header directly in __pppoe_xmit
  [PPP] pppoe: Fix data clobbering in __pppoe_xmit and return value
  [PPP] pppoe: Fix skb_unshare_check call position
  [SCTP]: Convert bind_addr_list locking to RCU
  [SCTP]: Add RCU synchronization around sctp_localaddr_list
  [PKT_SCHED]: sch_cbq.c: Shut up uninitialized variable warning
  [PKTGEN]: srcmac fix
  [IPV6]: Fix source address selection.
  [IPV4]: Just increment OutDatagrams once per a datagram.
  [IPV6]: Just increment OutDatagrams once per a datagram.
  [IPV6]: Fix unbalanced socket reference with MSG_CONFIRM.
  [NET_SCHED] protect action config/dump from irqs
  [NET]: Fix two issues wrt. SO_BINDTODEVICE.

Fix non-ISA link error in drivers/scsi/advansys.c

2007-09-17T04:13:58+00:00

When CONFIG_ISA is disabled, the isa_driver support will not be compiled
in.  Define stubs so that we don't get link-time errors.

Signed-off-by: Matthew Wilcox 
Signed-off-by: Linus Torvalds