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yaml
---
r: 211993
b: refs/heads/master
c: bc4016f
h: refs/heads/master
i:
  211991: a64edb9
v: v3
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Linus Torvalds committed Oct 21, 2010
1 parent ecae652 commit f1fc687
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Showing 469 changed files with 18,140 additions and 7,727 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: b7dadc38797584f6203386da1947ed5edf516646
refs/heads/master: bc4016f48161454a9a8e5eb209b0693c6cde9f62
14 changes: 4 additions & 10 deletions trunk/Documentation/DocBook/kernel-locking.tmpl
Original file line number Diff line number Diff line change
Expand Up @@ -1645,7 +1645,9 @@ the amount of locking which needs to be done.
all the readers who were traversing the list when we deleted the
element are finished. We use <function>call_rcu()</function> to
register a callback which will actually destroy the object once
the readers are finished.
all pre-existing readers are finished. Alternatively,
<function>synchronize_rcu()</function> may be used to block until
all pre-existing are finished.
</para>
<para>
But how does Read Copy Update know when the readers are
Expand Down Expand Up @@ -1714,7 +1716,7 @@ the amount of locking which needs to be done.
- object_put(obj);
+ list_del_rcu(&amp;obj-&gt;list);
cache_num--;
+ call_rcu(&amp;obj-&gt;rcu, cache_delete_rcu, obj);
+ call_rcu(&amp;obj-&gt;rcu, cache_delete_rcu);
}

/* Must be holding cache_lock */
Expand All @@ -1725,14 +1727,6 @@ the amount of locking which needs to be done.
if (++cache_num > MAX_CACHE_SIZE) {
struct object *i, *outcast = NULL;
list_for_each_entry(i, &amp;cache, list) {
@@ -85,6 +94,7 @@
obj-&gt;popularity = 0;
atomic_set(&amp;obj-&gt;refcnt, 1); /* The cache holds a reference */
spin_lock_init(&amp;obj-&gt;lock);
+ INIT_RCU_HEAD(&amp;obj-&gt;rcu);

spin_lock_irqsave(&amp;cache_lock, flags);
__cache_add(obj);
@@ -104,12 +114,11 @@
struct object *cache_find(int id)
{
Expand Down
46 changes: 39 additions & 7 deletions trunk/Documentation/RCU/checklist.txt
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Expand Up @@ -218,13 +218,22 @@ over a rather long period of time, but improvements are always welcome!
include:

a. Keeping a count of the number of data-structure elements
used by the RCU-protected data structure, including those
waiting for a grace period to elapse. Enforce a limit
on this number, stalling updates as needed to allow
previously deferred frees to complete.

Alternatively, limit only the number awaiting deferred
free rather than the total number of elements.
used by the RCU-protected data structure, including
those waiting for a grace period to elapse. Enforce a
limit on this number, stalling updates as needed to allow
previously deferred frees to complete. Alternatively,
limit only the number awaiting deferred free rather than
the total number of elements.

One way to stall the updates is to acquire the update-side
mutex. (Don't try this with a spinlock -- other CPUs
spinning on the lock could prevent the grace period
from ever ending.) Another way to stall the updates
is for the updates to use a wrapper function around
the memory allocator, so that this wrapper function
simulates OOM when there is too much memory awaiting an
RCU grace period. There are of course many other
variations on this theme.

b. Limiting update rate. For example, if updates occur only
once per hour, then no explicit rate limiting is required,
Expand Down Expand Up @@ -365,3 +374,26 @@ over a rather long period of time, but improvements are always welcome!
and the compiler to freely reorder code into and out of RCU
read-side critical sections. It is the responsibility of the
RCU update-side primitives to deal with this.

17. Use CONFIG_PROVE_RCU, CONFIG_DEBUG_OBJECTS_RCU_HEAD, and
the __rcu sparse checks to validate your RCU code. These
can help find problems as follows:

CONFIG_PROVE_RCU: check that accesses to RCU-protected data
structures are carried out under the proper RCU
read-side critical section, while holding the right
combination of locks, or whatever other conditions
are appropriate.

CONFIG_DEBUG_OBJECTS_RCU_HEAD: check that you don't pass the
same object to call_rcu() (or friends) before an RCU
grace period has elapsed since the last time that you
passed that same object to call_rcu() (or friends).

__rcu sparse checks: tag the pointer to the RCU-protected data
structure with __rcu, and sparse will warn you if you
access that pointer without the services of one of the
variants of rcu_dereference().

These debugging aids can help you find problems that are
otherwise extremely difficult to spot.
18 changes: 18 additions & 0 deletions trunk/Documentation/RCU/stallwarn.txt
Original file line number Diff line number Diff line change
Expand Up @@ -80,6 +80,24 @@ o A CPU looping with bottom halves disabled. This condition can
o For !CONFIG_PREEMPT kernels, a CPU looping anywhere in the kernel
without invoking schedule().

o A CPU-bound real-time task in a CONFIG_PREEMPT kernel, which might
happen to preempt a low-priority task in the middle of an RCU
read-side critical section. This is especially damaging if
that low-priority task is not permitted to run on any other CPU,
in which case the next RCU grace period can never complete, which
will eventually cause the system to run out of memory and hang.
While the system is in the process of running itself out of
memory, you might see stall-warning messages.

o A CPU-bound real-time task in a CONFIG_PREEMPT_RT kernel that
is running at a higher priority than the RCU softirq threads.
This will prevent RCU callbacks from ever being invoked,
and in a CONFIG_TREE_PREEMPT_RCU kernel will further prevent
RCU grace periods from ever completing. Either way, the
system will eventually run out of memory and hang. In the
CONFIG_TREE_PREEMPT_RCU case, you might see stall-warning
messages.

o A bug in the RCU implementation.

o A hardware failure. This is quite unlikely, but has occurred
Expand Down
13 changes: 12 additions & 1 deletion trunk/Documentation/RCU/trace.txt
Original file line number Diff line number Diff line change
Expand Up @@ -125,6 +125,17 @@ o "b" is the batch limit for this CPU. If more than this number
of RCU callbacks is ready to invoke, then the remainder will
be deferred.

o "ci" is the number of RCU callbacks that have been invoked for
this CPU. Note that ci+ql is the number of callbacks that have
been registered in absence of CPU-hotplug activity.

o "co" is the number of RCU callbacks that have been orphaned due to
this CPU going offline.

o "ca" is the number of RCU callbacks that have been adopted due to
other CPUs going offline. Note that ci+co-ca+ql is the number of
RCU callbacks registered on this CPU.

There is also an rcu/rcudata.csv file with the same information in
comma-separated-variable spreadsheet format.

Expand Down Expand Up @@ -180,7 +191,7 @@ o "s" is the "signaled" state that drives force_quiescent_state()'s

o "jfq" is the number of jiffies remaining for this grace period
before force_quiescent_state() is invoked to help push things
along. Note that CPUs in dyntick-idle mode thoughout the grace
along. Note that CPUs in dyntick-idle mode throughout the grace
period will not report on their own, but rather must be check by
some other CPU via force_quiescent_state().

Expand Down
8 changes: 5 additions & 3 deletions trunk/Documentation/kprobes.txt
Original file line number Diff line number Diff line change
Expand Up @@ -542,9 +542,11 @@ Kprobes does not use mutexes or allocate memory except during
registration and unregistration.

Probe handlers are run with preemption disabled. Depending on the
architecture, handlers may also run with interrupts disabled. In any
case, your handler should not yield the CPU (e.g., by attempting to
acquire a semaphore).
architecture and optimization state, handlers may also run with
interrupts disabled (e.g., kretprobe handlers and optimized kprobe
handlers run without interrupt disabled on x86/x86-64). In any case,
your handler should not yield the CPU (e.g., by attempting to acquire
a semaphore).

Since a return probe is implemented by replacing the return
address with the trampoline's address, stack backtraces and calls
Expand Down
13 changes: 12 additions & 1 deletion trunk/MAINTAINERS
Original file line number Diff line number Diff line change
Expand Up @@ -1527,6 +1527,8 @@ T: git git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client.git
S: Supported
F: Documentation/filesystems/ceph.txt
F: fs/ceph
F: net/ceph
F: include/linux/ceph

CERTIFIED WIRELESS USB (WUSB) SUBSYSTEM:
M: David Vrabel <david.vrabel@csr.com>
Expand Down Expand Up @@ -3162,7 +3164,7 @@ F: drivers/net/ioc3-eth.c

IOC3 SERIAL DRIVER
M: Pat Gefre <pfg@sgi.com>
L: linux-mips@linux-mips.org
L: linux-serial@vger.kernel.org
S: Maintained
F: drivers/serial/ioc3_serial.c

Expand Down Expand Up @@ -4805,6 +4807,15 @@ F: fs/qnx4/
F: include/linux/qnx4_fs.h
F: include/linux/qnxtypes.h

RADOS BLOCK DEVICE (RBD)
F: include/linux/qnxtypes.h
M: Yehuda Sadeh <yehuda@hq.newdream.net>
M: Sage Weil <sage@newdream.net>
M: ceph-devel@vger.kernel.org
S: Supported
F: drivers/block/rbd.c
F: drivers/block/rbd_types.h

RADEON FRAMEBUFFER DISPLAY DRIVER
M: Benjamin Herrenschmidt <benh@kernel.crashing.org>
L: linux-fbdev@vger.kernel.org
Expand Down
15 changes: 13 additions & 2 deletions trunk/Makefile
Original file line number Diff line number Diff line change
@@ -1,8 +1,8 @@
VERSION = 2
PATCHLEVEL = 6
SUBLEVEL = 36
EXTRAVERSION = -rc7
NAME = Sheep on Meth
EXTRAVERSION =
NAME = Flesh-Eating Bats with Fangs

# *DOCUMENTATION*
# To see a list of typical targets execute "make help"
Expand Down Expand Up @@ -568,6 +568,12 @@ endif

ifdef CONFIG_FUNCTION_TRACER
KBUILD_CFLAGS += -pg
ifdef CONFIG_DYNAMIC_FTRACE
ifdef CONFIG_HAVE_C_RECORDMCOUNT
BUILD_C_RECORDMCOUNT := y
export BUILD_C_RECORDMCOUNT
endif
endif
endif

# We trigger additional mismatches with less inlining
Expand All @@ -591,6 +597,11 @@ KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow)
# conserve stack if available
KBUILD_CFLAGS += $(call cc-option,-fconserve-stack)

# check for 'asm goto'
ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC)), y)
KBUILD_CFLAGS += -DCC_HAVE_ASM_GOTO
endif

# Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
# But warn user when we do so
warn-assign = \
Expand Down
3 changes: 3 additions & 0 deletions trunk/arch/Kconfig
Original file line number Diff line number Diff line change
Expand Up @@ -158,4 +158,7 @@ config HAVE_PERF_EVENTS_NMI
subsystem. Also has support for calculating CPU cycle events
to determine how many clock cycles in a given period.

config HAVE_ARCH_JUMP_LABEL
bool

source "kernel/gcov/Kconfig"
1 change: 1 addition & 0 deletions trunk/arch/alpha/Kconfig
Original file line number Diff line number Diff line change
Expand Up @@ -9,6 +9,7 @@ config ALPHA
select HAVE_IDE
select HAVE_OPROFILE
select HAVE_SYSCALL_WRAPPERS
select HAVE_IRQ_WORK
select HAVE_PERF_EVENTS
select HAVE_DMA_ATTRS
help
Expand Down
5 changes: 0 additions & 5 deletions trunk/arch/alpha/include/asm/perf_event.h
Original file line number Diff line number Diff line change
@@ -1,11 +1,6 @@
#ifndef __ASM_ALPHA_PERF_EVENT_H
#define __ASM_ALPHA_PERF_EVENT_H

/* Alpha only supports software events through this interface. */
extern void set_perf_event_pending(void);

#define PERF_EVENT_INDEX_OFFSET 0

#ifdef CONFIG_PERF_EVENTS
extern void init_hw_perf_events(void);
#else
Expand Down
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