It took me quite a while to understand how rwsem's count field
mainifested itself in different scenarios.
Add comments to provide a quick reference to the the rwsem's count
field for each scenario where readers and writers are contending
for the lock.
Hopefully it will be useful for future maintenance of the code and
for people to get up to speed on how the logic in the code works.
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Davidlohr Bueso <davidlohr@hp.com>
Cc: Alex Shi <alex.shi@linaro.org>
Cc: Michel Lespinasse <walken@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Paul E.McKenney <paulmck@linux.vnet.ibm.com>
Cc: Jason Low <jason.low2@hp.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1399060437.2970.146.camel@schen9-DESK
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Update the documentation to reflect the change of barrier primitives.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
Link: http://lkml.kernel.org/n/tip-xslfehiga1twbk5uk94rij1e@git.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Xtensa SMP has compare-and-swap which is fully serializing, therefore
its exising smp_mb__{before,after}_clear_bit() appear unduly heavy.
Implement the new barriers as barrier().
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-e9rqjxr1m1ejsob9p433kmji@git.kernel.org
Cc: Chris Zankel <chris@zankel.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-xtensa@linux-xtensa.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
x86 is strongly ordered and all its atomic ops imply a full barrier.
Implement the two new primitives as the old ones were.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-knswsr5mldkr0w1lrdxvc81w@git.kernel.org
Cc: Dave Jones <davej@redhat.com>
Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michel Lespinasse <walken@google.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Implement the new smp_mb__* ops as per the old ones.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Link: http://lkml.kernel.org/n/tip-euuabnf5a3u23fy4fq8m3jcg@git.kernel.org
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Chen Gang <gang.chen@asianux.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
sparc32: fully relies on asm-generic/barrier.h and thus can use its
implementation.
sparc64: is strongly ordered and its atomic ops imply a full barrier,
implement the new primitives using barrier().
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: David S. Miller <davem@davemloft.net>
Link: http://lkml.kernel.org/n/tip-2cla9ubpd8chrntnm7e4zdt4@git.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-kernel@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
score fully relies on asm-generic/barrier.h, so it can use its default
implementation.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Lennox Wu <lennox.wu@gmail.com>
Link: http://lkml.kernel.org/n/tip-4mv9svf28lnotjpfuza8urh8@git.kernel.org
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
As per the existing implementation; implement the new one using
smp_mb().
AFAICT the s390 compare-and-swap does imply a barrier, however there
are some immediate ops that seem to be singly-copy atomic and do not
imply a barrier. One such is the "ni" op (which would be
and-immediate) which is used for the constant clear_bit
implementation. Therefore s390 needs full barriers for the
{before,after} atomic ops.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-kme5dz5hcobpnufnnkh1ech2@git.kernel.org
Cc: Chen Gang <gang.chen@asianux.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux390@de.ibm.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Powerpc allows reordering over its ll/sc implementation. Implement the
two new barriers as appropriate.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-gg2ffgq32sjgy9b8lj6m3hsc@git.kernel.org
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-kernel@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
mn10300 fully relies on asm-generic/barrier.h and therefore its
smp_mb() is barrier(). We can use the default implementation.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-wotyeoj99h1dpojjeest2jbk@git.kernel.org
Cc: David Howells <dhowells@redhat.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-am33-list@redhat.com
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
MIPS is interesting and has hardware variants that reorder over ll/sc
as well as those that do not.
Implement the 2 new barrier functions as per the old barriers.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-9ph49jbae3hol9v721sbc2g6@git.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Maciej W. Rozycki" <macro@codesourcery.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Implement the new barriers; as per the old versions the metag atomic
imply a full barrier.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-dqnyo215kq38wi4xcxnbpjw3@git.kernel.org
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-metag@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
m68k uses asm-generic/barrier.h and its smp_mb() is barrier(),
therefore we can use the generic versions that use smp_mb().
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-s5dvosrb7qhvpmtaffwfn0zg@git.kernel.org
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-m68k@lists.linux-m68k.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
ia64 atomic ops are full barriers; implement the new
smp_mb__{before,after}_atomic().
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-hyp7yj68cmqz1nqbfpr541ca@git.kernel.org
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-ia64@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Hexagon uses asm-gemeric/barrier.h and its smp_mb() is barrier().
Therefore we can use the default implementation that uses smp_mb().
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-87irqrrbgizeojjfdqhypud3@git.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: linux-hexagon@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Because:
arch/frv/include/asm/smp.h:#error SMP not supported
smp_mb() is barrier() and we can use the default implementation that
uses smp_mb().
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-n296g51yzdu5ru1vp7mccxmf@git.kernel.org
Cc: David Howells <dhowells@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cris fully relies on asm-generic/barrier.h, therefore its smp_mb() is
barrier(), thus we can use the default implementation that uses
smp_mb().
(Include asm/system.h and asm/barrier.h to avoid header dependency hell.)
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-wvewbe8os3s1e4pt1cdotuee@git.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mikael Starvik <starvik@axis.com>
Cc: linux-cris-kernel@axis.com
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
c6x doesn't have a barrier.h and completely relies on
asm-generic/barrier.h. Therefore its smp_mb() is barrier() and we can
use the default versions that are smp_mb().
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Mark Salter <msalter@redhat.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-kl53k3pyj0rbd80jq8ralpf3@git.kernel.org
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Salter <msalter@redhat.com>
Cc: linux-c6x-dev@linux-c6x.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Blackfin's atomic primitives do not imply a full barrier as whitnessed
from its SMP smp_mb__{before,after}_clear_bit() implementations.
However since !SMP smp_mb() reduces to barrier() remove everything and
rely on the asm-generic/barrier.h implentation.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-1widdkdsb3c1titq8jez6g3g@git.kernel.org
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Steven Miao <realmz6@gmail.com>
Cc: adi-buildroot-devel@lists.sourceforge.net
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
AARGH64 uses ll/sc primitives that do not imply any barriers for the
normal atomics, therefore smp_mb__{before,after} should be a full
barrier.
Since AARGH64 doesn't use asm-generic/barrier.h, add the required
definitions to its asm/barrier.h.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-8p5iclqgy78al33kck3ht7nr@git.kernel.org
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Gang <gang.chen@asianux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
ARM uses ll/sc primitives that do not imply barriers for all regular
atomic ops, therefore smp_mb__{before,after} need be a full barrier.
Since ARM doesn't use asm-generic/barrier.h include the required
definitions in its asm/barrier.h
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-yijo7sglsl7uusbp13upcuvo@git.kernel.org
Cc: Albin Tonnerre <albin.tonnerre@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Gang <gang.chen@asianux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nicolas Pitre <nico@linaro.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Victor Kamensky <victor.kamensky@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The arc mb() implementation is a compiler barrier(), therefore it all
doesn't matter one way or the other. Simply remove the existing
definitions and use whatever is generated by the defaults.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-ua48a59wri3ybz1rz8i7uvbr@git.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The Alpha ll/sc primitives do not imply any sort of barrier; therefore
the smp_mb__{before,after} should be a full barrier. This is the
default from asm-generic/barrier.h and therefore just remove the
current definitions.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-iacwfd15lq3ta2v7jut747r7@git.kernel.org
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: linux-alpha@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Since the smp_mb__{before,after}*() ops are fundamentally dependent on
how an arch can implement atomics it doesn't make sense to have 3
variants of them. They must all be the same.
Furthermore, the 3 variants suggest they're only valid for those 3
atomic ops, while we have many more where they could be applied.
So move away from
smp_mb__{before,after}_{atomic,clear}_{dec,inc,bit}() and reduce the
interface to just the two: smp_mb__{before,after}_atomic().
This patch prepares the way by introducing default implementations in
asm-generic/barrier.h that default to a full barrier and providing
__deprecated inlines for the previous 6 barriers if they're not
provided by the arch.
This should allow for a mostly painless transition (lots of deprecated
warns in the interim).
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-wr59327qdyi9mbzn6x937s4e@git.kernel.org
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Chen, Gong" <gong.chen@linux.intel.com>
Cc: John Sullivan <jsrhbz@kanargh.force9.co.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mauro Carvalho Chehab <m.chehab@samsung.com>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Both already use asm-generic/barrier.h as per their
include/asm/Kbuild. Remove the stale files.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-c7vlkshl3tblim0o8z2p70kt@git.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: linux-hexagon@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
IA64 doesn't actually have acquire/release barriers, its a lie!
Add a comment explaining this and fix up the bitop barriers.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-akevfh136um9dqvb1ohm55ca@git.kernel.org
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-ia64@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull parisc updates from Helge Deller:
"There are two major changes in this patchset:
The major fix is that the epoll_pwait() syscall for 32bit userspace
was not using the compat wrapper on a 64bit kernel.
Secondly we changed the value of SHMLBA from 4MB to PAGE_SIZE to
reflect that we can actually mmap to any multiple of PAGE_SIZE. The
only thing which needs care is that shared mmaps need to be mapped at
the same offset inside the 4MB cache window"
* 'parisc-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc: fix epoll_pwait syscall on compat kernel
parisc: change value of SHMLBA from 0x00400000 to PAGE_SIZE
parisc: Replace __get_cpu_var uses for address calculation
Merge ipmi fixes from Corey Minyard:
"Things collected since last kernel release.
Some of these are pretty important. The first three are bug fixes.
The next two are to hopefully make everyone happy about allowing
ACPI to be on all the time and not have IPMI have an effect on the
system when not in use. The last is a little cleanup"
* emailed patches from Corey Minyard <cminyard@mvista.com>:
ipmi: boolify some things
ipmi: Turn off all activity on an idle ipmi interface
ipmi: Turn off default probing of interfaces
ipmi: Reset the KCS timeout when starting error recovery
ipmi: Fix a race restarting the timer
Char: ipmi_bt_sm, fix infinite loop
The IPMI driver would wake up periodically looking for events and
watchdog pretimeouts. If there is nothing waiting for these events,
it's really kind of pointless to be checking for them. So modify the
driver so the message handler can pass down if it needs the lower layer
to be waiting for these. Modify the system interface lower layer to
turn off all timer and thread activity if the upper layer doesn't need
anything and it is not currently handling messages. And modify the
message handler to not restart the timer if its timer is not needed.
The timers and kthread will still be enabled if:
- the SI interface is handling a message.
- a user has enabled watching for events.
- the IPMI watchdog timer is in use (since it uses pretimeouts).
- the message handler is waiting on a remote response.
- a user has registered to receive commands.
This mostly affects interfaces without interrupts. Interfaces with
interrupts already don't use CPU in the system interface when the
interface is idle.
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The default probing can cause problems with some system, slow booting,
extra CPU usages, etc. Turn it off by default and give a config option
to enable it.
From: Matthew Garrett <matthew.garrett@nebula.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The OBF timer in KCS was not reset in one situation when error recovery
was started, resulting in an immediate timeout.
Reported-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With recent changes it is possible for the timer handler to detect an
idle interface and not start the timer, but the thread to start an
operation at the same time. The thread will not start the timer in that
instance, resulting in the timer not running.
Instead, move all timer operations under the lock and start the timer in
the thread if it detect non-idle and the timer is not already running.
Moving under locks allows the last timeout to be set in both the thread
and the timer. 'Timer is not running' means that the timer is not
pending and smi_timeout() is not running. So we need a flag to detect
this correctly.
Also fix a few other timeout bugs: setting the last timeout when the
interrupt has to be disabled and the timer started, and setting the last
timeout in check_start_timer_thread possibly racing with the timer
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In read_all_bytes, we do
unsigned char i;
...
bt->read_data[0] = BMC2HOST;
bt->read_count = bt->read_data[0];
...
for (i = 1; i <= bt->read_count; i++)
bt->read_data[i] = BMC2HOST;
If bt->read_data[0] == bt->read_count == 255, we loop infinitely in the
'for' loop. Make 'i' an 'int' instead of 'char' to get rid of the
overflow and finish the loop after 255 iterations every time.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Reported-and-debugged-by: Rui Hui Dian <rhdian@novell.com>
Cc: Tomas Cech <tcech@suse.cz>
Cc: Corey Minyard <minyard@acm.org>
Cc: <openipmi-developer@lists.sourceforge.net>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Fix completely broken 32-bit PV guests caused by x86 refactoring
32-bit thread_info.
- Only enable ticketlock slow path on Xen (not bare metal).
- Fix two bugs with PV guests not shutting down when requested.
- Fix a minor memory leak in xen-pciback error path.
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Merge tag 'stable/for-linus-3.15-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull Xen fixes from David Vrabel:
"Xen regression and bug fixes for 3.15-rc1:
- fix completely broken 32-bit PV guests caused by x86 refactoring
32-bit thread_info.
- only enable ticketlock slow path on Xen (not bare metal)
- fix two bugs with PV guests not shutting down when requested
- fix a minor memory leak in xen-pciback error path"
* tag 'stable/for-linus-3.15-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen/manage: Poweroff forcefully if user-space is not yet up.
xen/xenbus: Avoid synchronous wait on XenBus stalling shutdown/restart.
xen/spinlock: Don't enable them unconditionally.
xen-pciback: silence an unwanted debug printk
xen: fix memory leak in __xen_pcibk_add_pci_dev()
x86/xen: Fix 32-bit PV guests's usage of kernel_stack
drivers/video/fbdev/ and the fbdev framework core files are located in
drivers/video/fbdev/core/
The drivers/video/Kconfig is modified so that the DRM and the fbdev menu
options are in separate submenus, instead of both being mixed in the same
'Graphics support' menu level.
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Merge tag 'fbdev-reorder-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tomba/linux
Pull fbdev renaming patches from Tomi Valkeinen:
"Reorder drivers/video/ directory so that all fbdev drivers are now
located in drivers/video/fbdev/ and the fbdev framework core files are
located in drivers/video/fbdev/core/
The drivers/video/Kconfig is modified so that the DRM and the fbdev
menu options are in separate submenus, instead of both being mixed in
the same 'Graphics support' menu level"
* tag 'fbdev-reorder-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tomba/linux:
video: Kconfig: move drm and fb into separate menus
fbdev: move fbdev core files to separate directory
video: move fbdev to drivers/video/fbdev
I hit another BUG_ON with e240c1839d. In __get_priority_stripe(),
stripe count equals to 0 initially. Between atomic_inc and BUG_ON,
get_active_stripe() finds the stripe. So the stripe count isn't 1 any more.
V2: keeps the BUG_ON suggested by Neil.
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
At the moment the "Device Drivers / Graphics support" kernel config page
looks rather messy, with DRM and fbdev driver selections on the same
page, some on the top level Graphics support page, some under their
respective subsystems.
If I'm not mistaken, this is caused by the drivers depending on other
things than DRM or FB, which causes Kconfig to arrange the options in
not-so-neat manner.
Both DRM and FB have a main menuconfig option for the whole DRM or FB
subsystem. Optimally, this would be enough to arrange all DRM and FB
options under the respective subsystem, but for whatever reason this
doesn't work reliably.
This patch adds an explicit submenu for DRM and FB, making it much
clearer which options are related to FB, and which to DRM.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Instead of having fbdev framework core files at the root fbdev
directory, mixed with random fbdev device drivers, move the fbdev core
files to a separate core directory. This makes it much clearer which of
the files are actually part of the fbdev framework, and which are part
of device drivers.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Rob Clark <robdclark@gmail.com>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
The drivers/video directory is a mess. It contains generic video related
files, directories for backlight, console, linux logo, lots of fbdev
device drivers, fbdev framework files.
Make some order into the chaos by creating drivers/video/fbdev
directory, and move all fbdev related files there.
No functionality is changed, although I guess it is possible that some
subtle Makefile build order related issue could be created by this
patch.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Rob Clark <robdclark@gmail.com>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Pull x86 fixes from Ingo Molnar:
"Various fixes:
- reboot regression fix
- build message spam fix
- GPU quirk fix
- 'make kvmconfig' fix
plus the wire-up of the renameat2() system call on i386"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Remove the PCI reboot method from the default chain
x86/build: Supress "Nothing to be done for ..." messages
x86/gpu: Fix sign extension issue in Intel graphics stolen memory quirks
x86/platform: Fix "make O=dir kvmconfig"
i386: Wire up the renameat2() syscall
Pull perf fixes from Ingo Molnar:
"Tooling fixes, plus a simple hardware-enablement patch for the Intel
RAPL PMU (energy use measurement) on Haswell CPUs, which I hope is
still fine at this stage"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf tools: Instead of redirecting flex output, use -o
perf tools: Fix double free in perf test 21 (code-reading.c)
perf stat: Initialize statistics correctly
perf bench: Set more defaults in the 'numa' suite
perf bench: Fix segfault at the end of an 'all' execution
perf bench: Update manpage to mention numa and futex
perf probe: Use dwarf_getcfi_elf() instead of dwarf_getcfi()
perf probe: Fix to handle errors in line_range searching
perf probe: Fix --line option behavior
perf tools: Pick up libdw without explicit LIBDW_DIR
MAINTAINERS: Change e-mail to kernel.org one
perf callchains: Disable unwind libraries when libelf isn't found
tools lib traceevent: Do not call warning() directly
tools lib traceevent: Print event name when show warning if possible
perf top: Fix documentation of invalid -s option
perf/x86: Enable DRAM RAPL support on Intel Haswell
