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  1. 15 3月, 2010 1 次提交
  3. 08 3月, 2010 1 次提交
    • L
      Revert "lib: build list_sort() only if needed" · b8fa0571
      由 Linus Torvalds 提交于 
      This reverts commit a069c266.

It turns ou that not only was it missing a case (XFS) that needed it,
but perhaps more importantly, people sometimes want to enable new
modules that they hadn't had enabled before, and if such a module uses
list_sort(), it can't easily be inserted any more.

So rather than add a "select LIST_SORT" to the XFS case, just leave it
compiled in.  It's not all _that_ big, after all, and the inconvenience
isn't worth it.
Requested-by: NAlexey Dobriyan <adobriyan@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Don Mullis <don.mullis@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      b8fa0571
  5. 07 3月, 2010 13 次提交
  7. 25 2月, 2010 4 次提交
    • P
      rcu: Add RCU_CPU_STALL_VERBOSE to dump detailed per-task information · 1ed509a2
      由 Paul E. McKenney 提交于 
      When RCU detects a grace-period stall, it currently just prints
out the PID of any tasks doing the stalling.  This patch adds
RCU_CPU_STALL_VERBOSE, which enables the more-verbose reporting
from sched_show_task().
Suggested-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1266887105-1528-21-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      1ed509a2
    • P
      idr: Apply lockdep-based diagnostics to rcu_dereference() uses · 96be753a
      由 Paul E. McKenney 提交于 
      Because idr can be used with any of a number of locks or with
any flavor of RCU, just disable the lockdep-based diagnostics.
If idr needs diagnostics, the check expression will need to be
passed into the relevant idr primitives as an additional
argument.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1266887105-1528-11-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      96be753a
    • P
      radix-tree: Disable RCU lockdep checking in radix tree · 2676a58c
      由 Paul E. McKenney 提交于 
      Because the radix tree is used with many different locking
designs, we cannot do any effective checking without changing
the radix-tree APIs. It might make sense to do this later, but
only if the RCU lockdep checking proves itself sufficiently
valuable.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1266887105-1528-10-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      2676a58c
    • P
      rcu: Introduce lockdep-based checking to RCU read-side primitives · 632ee200
      由 Paul E. McKenney 提交于 
      Inspection is proving insufficient to catch all RCU misuses,
which is understandable given that rcu_dereference() might be
protected by any of four different flavors of RCU (RCU, RCU-bh,
RCU-sched, and SRCU), and might also/instead be protected by any
of a number of locking primitives. It is therefore time to
enlist the aid of lockdep.

This set of patches is inspired by earlier work by Peter
Zijlstra and Thomas Gleixner, and takes the following approach:

o	Set up separate lockdep classes for RCU, RCU-bh, and RCU-sched.

o	Set up separate lockdep classes for each instance of SRCU.

o	Create primitives that check for being in an RCU read-side
	critical section.  These return exact answers if lockdep is
	fully enabled, but if unsure, report being in an RCU read-side
	critical section.  (We want to avoid false positives!)
	The primitives are:

	For RCU: rcu_read_lock_held(void)

	For RCU-bh: rcu_read_lock_bh_held(void)

	For RCU-sched: rcu_read_lock_sched_held(void)

	For SRCU: srcu_read_lock_held(struct srcu_struct *sp)

o	Add rcu_dereference_check(), which takes a second argument
	in which one places a boolean expression based on the above
	primitives and/or lockdep_is_held().

o	A new kernel configuration parameter, CONFIG_PROVE_RCU, enables
	rcu_dereference_check().  This depends on CONFIG_PROVE_LOCKING,
	and should be quite helpful during the transition period while
	CONFIG_PROVE_RCU-unaware patches are in flight.

The existing rcu_dereference() primitive does no checking, but
upcoming patches will change that.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1266887105-1528-1-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      632ee200
  9. 23 2月, 2010 1 次提交
  11. 05 2月, 2010 1 次提交
  13. 03 2月, 2010 2 次提交
    • M
      lmb: Add lmb_free() · 24551f64
      由 Michael Ellerman 提交于 
      We can free memory allocated with lmb_alloc() by removing it from the
list of reserved LMBs. Rework lmb_remove() to allow that possibility
and add lmb_free() which exploits it.

BenH: Removed some useless parenthesis
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      24551f64
    • T
      idr: fix a critical misallocation bug · 859ddf09
      由 Tejun Heo 提交于 
      Eric Paris located a bug in idr.  With IDR_BITS of 6, it grows to three
layers when id 4096 is first allocated.  When that happens, idr wraps
incorrectly and searches the idr array ignoring the high bits.  The
following test code from Eric demonstrates the bug nicely.

#include <linux/idr.h>
#include <linux/kernel.h>
#include <linux/module.h>

static DEFINE_IDR(test_idr);

int init_module(void)
{
	int ret, forty95, forty96;
	void *addr;

	/* add 2 entries both with 4095 as the start address */
again1:
	if (!idr_pre_get(&test_idr, GFP_KERNEL))
		return -ENOMEM;
	ret = idr_get_new_above(&test_idr, (void *)4095, 4095, &forty95);
	if (ret) {
		if (ret == -EAGAIN)
			goto again1;
		return ret;
	}
	if (forty95 != 4095)
		printk(KERN_ERR "hmmm, forty95=%d\n", forty95);

again2:
	if (!idr_pre_get(&test_idr, GFP_KERNEL))
		return -ENOMEM;
	ret = idr_get_new_above(&test_idr, (void *)4096, 4095, &forty96);
	if (ret) {
		if (ret == -EAGAIN)
			goto again2;
		return ret;
	}
	if (forty96 != 4096)
		printk(KERN_ERR "hmmm, forty96=%d\n", forty96);

	/* try to find the 2 entries, noticing that 4096 broke */
	addr = idr_find(&test_idr, forty95);
	if ((int)addr != forty95)
		printk(KERN_ERR "hmmm, after find forty95=%d addr=%d\n", forty95, (int)addr);
	addr = idr_find(&test_idr, forty96);
	if ((int)addr != forty96)
		printk(KERN_ERR "hmmm, after find forty96=%d addr=%d\n", forty96, (int)addr);
	/* really weird, the entry which should be at 4096 is actually at 0!! */
	addr = idr_find(&test_idr, 0);
	if ((int)addr)
		printk(KERN_ERR "found an entry at id=0 for addr=%d\n", (int)addr);

	idr_remove(&test_idr, forty95);
	idr_remove(&test_idr, forty96);

	return 0;
}

void cleanup_module(void)
{
}

MODULE_AUTHOR("Eric Paris <eparis@redhat.com>");
MODULE_DESCRIPTION("Simple idr test");
MODULE_LICENSE("GPL");

This happens because when sub_alloc() back tracks it doesn't always do it
step-by-step while the over-the-limit detection assumes step-by-step
backtracking.  The logic in sub_alloc() looks like the following.

  restart:
    clear pa[top level + 1] for end cond detection
    l = top level
    while (true) {
	search for empty slot at this level
	if (not found) {
	    push id to the next possible value
	    l++
A:	    if (pa[l] is clear)
	        failed, return asking caller to grow the tree
	    if (going up 1 level gives more slots to search)
	        continue the while loop above with the incremented l
	    else
C:	        goto restart
	}
	adjust id accordingly to the found slot
	if (l == 0)
	    return found id;
	create lower level if not there yet
	record pa[l] and l--
    }

Test A is the fail exit condition but this assumes that failure is
propagated upwared one level at a time but the B optimization path breaks
the assumption and restarts the whole thing with a start value which is
above the possible limit with the current layers.  sub_alloc() assumes the
start id value is inside the limit when called and test A is the only exit
condition check, so it ends up searching for empty slot while ignoring
high set bit.

So, for 4095->4096 test, level0 search fails but pa[1] contains a valid
pointer.  However, going up 1 level wouldn't give any more empty slot so
it takes C and when the whole thing restarts nobody notices the high bit
set beyond the top level.

This patch fixes the bug by changing the fail exit condition check to full
id limit check.

Based-on-patch-from: Eric Paris <eparis@redhat.com>
Reported-by: NEric Paris <eparis@redhat.com>
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      859ddf09
  15. 27 1月, 2010 1 次提交
  17. 23 1月, 2010 1 次提交
  19. 16 1月, 2010 1 次提交
    • P
      rcu: 1Q2010 update for RCU documentation · 4c54005c
      由 Paul E. McKenney 提交于 
      Add expedited functions.  Review documentation and update
obsolete verbiage.  Also fix the advice for the RCU CPU-stall
kernel configuration parameter, and document RCU CPU-stall
warnings.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <12635142581866-git-send-email->
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      4c54005c
  21. 15 1月, 2010 1 次提交
  23. 14 1月, 2010 2 次提交
    • J
      lib/vsprintf.c: Add IPV4 options %pI4[hnbl] for host, network, big and little endian · 0159f24e
      由 Joe Perches 提交于 
      This should allow the removal of the #defines and uses
of NIPQUAD and NIPQUAD_FMT
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      0159f24e
    • B
      zlib: Fix build of powerpc boot wrapper · 6846ee5c
      由 Benjamin Herrenschmidt 提交于 
      Commit ac4c2a3b broke the build
of all powerpc boot wrappers.

It attempts to add an include of autoconf.h but used the wrong
path for it. It also adds -D__KERNEL__ to our boot wrapper, both
things that we pretty much didn't do on purpose so far.

We want our boot wrapper to remain independent enough of the kernel
for various reasons, one of them being that you can "wrap" an existing
kernel at distro install time which allows to ship one kernel image
and a set of boot wrappers for different platforms, the wrappers
don't have to be built out of the same kernel build tree.

It's also incorrect to do what the patch does in our boot environment
since we may not have a proper alignment exception handler which means
we may not be able to fixup the few cases where an unaligned access will
need SW emulation (depends on the core variant, could be when crossing
page or segment boundaries for example).

This patch fixes it by putting the old code back in and using the
new "fancy" variant only when CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
is set, which happens not to be set on powerpc since we don't include
autoconf.h. It also reverts the changes to our boot wrapper Makefile.

This means that x86 should, afaik, keep the optimisations since its
boot wrapper does include autoconf.h and define __KERNEL__ (though I
doubt they make that much different outside of slow embedded processors).
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      6846ee5c
  25. 13 1月, 2010 1 次提交
  27. 12 1月, 2010 6 次提交
  29. 11 1月, 2010 1 次提交
  31. 08 1月, 2010 1 次提交
    • J
      lib/vsprintf.c: Add %pMF to format FDDI bit reversed MAC addresses · bc7259a2
      由 Joe Perches 提交于 
      On Mon, 2010-01-04 at 23:43 +0000, Maciej W. Rozycki wrote:
> The example below shows an address, and the sequence of bits or symbols
> that would be transmitted when the address is used in the Source Address
> or Destination Address fields on the MAC header.  The transmission line
> shows the address bits in the order transmitted, from left to right.  For
> IEEE 802 LANs these correspond to actual bits on the medium.  The FDDI
> symbols line shows how the FDDI PHY sends the address bits as encoded
> symbols.
>
>         MSB:            35:7B:12:00:00:01
>         Canonical:      AC-DE-48-00-00-80
>         Transmission:   00110101 01111011 00010010 00000000 00000000 00000001
>         FDDI Symbols:   35 7B 12 00 00 01"
>
> Please note that this address has its group bit clear.
>
>  This notation is also defined in the "FDDI MEDIA ACCESS CONTROL-2
> (MAC-2)" (X3T9/92-120) document although that book does not have a need
> to use the MSB form and it's skipped.

Adds 6 bytes to object size for x86

New:
$ size lib/vsprintf.o
   text	   data	    bss	    dec	    hex	filename
   8664	      0	      2	   8666	   21da	lib/vsprintf.o
$ size lib/vsprintf.o
   text    data     bss     dec     hex filename
   8658       0       2    8660    21d4 lib/vsprintf.o
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      bc7259a2
  33. 31 12月, 2009 1 次提交
    • I
      dma-debug: Fix bug causing build warning · a8fe9ea2
      由 Ingo Molnar 提交于 
      Stephen Rothwell reported the following build warning:

 lib/dma-debug.c: In function 'dma_debug_device_change':
 lib/dma-debug.c:680: warning: 'return' with no value, in function returning non-void

Introduced by commit f797d988
("dma-debug: Do not add notifier when dma debugging is disabled").

Return 0 [notify-done] when disabled. (this is standard bus notifier behavior.)
Signed-off-by: NShaun Ruffell <sruffell@digium.com>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: <stable@kernel.org>
LKML-Reference: <20091231125624.GA14666@liondog.tnic>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      a8fe9ea2
  35. 28 12月, 2009 1 次提交
    • A
      x86, core: Optimize hweight32() · 39d997b5
      由 Akinobu Mita 提交于 
      Optimize hweight32 by using the same technique in hweight64.

The proof of this technique can be found in the commit log for
f9b41929 ("bitops: hweight()
speedup").

The userspace benchmark on x86_32 showed 20% speedup with
bitmap_weight() which uses hweight32 to count bits for each
unsigned long on 32bit architectures.

 int main(void)
 {
	#define SZ (1024 * 1024 * 512)

	static DECLARE_BITMAP(bitmap, SZ) = {
	        [0 ... 100] = 1,
	};

	return bitmap_weight(bitmap, SZ);
 }
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <1258603932-4590-1-git-send-email-akinobu.mita@gmail.com>
[ only x86 sets ARCH_HAS_FAST_MULTIPLIER so we do this via the x86 tree]
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      39d997b5