1. Nontemporal store for spin unlock.
A nontemporal store will not update the LRU setting for the cacheline. The
cacheline with the lock may therefore be evicted faster from the cpu
caches. Doing so may be useful since it increases the chance that the
exclusive cache line has been evicted when another cpu is trying to
acquire the lock.
The time between dropping and reacquiring a lock on the same cpu is
typically very small so the danger of the cacheline being
evicted is negligible.
2. Avoid semaphore operation in write_unlock and use nontemporal store
write_lock uses a cmpxchg like the regular spin_lock but write_unlock uses
clear_bit which requires a load and then a loop over a cmpxchg. The
following patch makes write_unlock simply use a nontemporal store to clear
the highest 8 bits. We will then still have the lower 3 bytes (24 bits)
left to count the readers.
Doing the byte store will reduce the number of possible readers from 2^31
to 2^24 = 16 million.
These patches were discussed already:
http://marc.theaimsgroup.com/?t=111472054400001&r=1&w=2http://marc.theaimsgroup.com/?l=linux-ia64&m=111401837707849&w=2
The nontemporal stores will only work using GCC. If a compiler is used
that does not support inline asm then fallback C code is used. This
will preserve the byte store but not be able to do the nontemporal stores.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
We have a chek in there to make sure that the name won't overflow
task_struct.comm[], but it's triggering for scsi with lots of HBAs, only
scsi is using single-threaded workqueues which don't append the "/%d"
anyway.
All too hard. Just kill the BUG_ON.
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
[ kthread_create() uses vsnprintf() and limits the thing, so no
actual overflow can actually happen regardless ]
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Even though the changes are minor for the next release an increasing
version number simplifies my support issues.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The workaround for broken device-tree that prevents fan control from
working on recent G5 models need to be "enabled" for machines with
revision 0x37 of the bridge in addition to machines with revision 0x35.
Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Need to use list_for_entry_safe(), as we're removing items during the
traversal. list_for_each_entry() uses the first ptr also as an iterator, if
you kfree() it slab takes it, might poison it and then you try to use it to
iterate to the next object in list.
Cc: Vojtech Pavlik <vojtech@suse.cz>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix the p-persistence CSMA algorithm which in simplex mode was starting
with a slottime delay before doing anything else as if there was carrier
collision resulting in bad performance on simplex links.
Signed-off-by: Ralf Baechle DL5RB <ralf@linux-mips.org>
Acked-by: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
sata_sx4 directly references sg->length to calculate total_len in
pdc20621_dma_prep(). This is incorrect as dma_map_sg() could have
merged multiple sg's into one and, in such case, sg->length doesn't
reflect true size of the entry. This patch makes it use
sg_dma_len(sg).
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
Patch from Ben Dooks
Rename the s3c2410_report_oc() to s3c2410_usb_report_oc()
as this is an usb specific function.
Change port power on the usb-simtec implementation to only
power up the output if both are set, as per the usb 1.1
specification
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Ben Dooks
Documentation for the in-built OHCI host controller
and the support for it in Linux.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Unfortunately, we can't use the "user" bit in the page tables to
control whether a page table entry is "global" or "asid" specific,
since the vector page is mapped as "user" accessible but is not
process specific.
Therefore, give direct control of the ARMv6 "nG" (not global)
bit to the mm layers.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
1. Move hwif_to_node to ide.h
2. Use hwif_to_node in ide-disk.c
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch removes the tda9887 stuff from lgdt330x.c. It's experimental code
which wasn't supposed to leak out and we don't want it in 2.6.13.
Signed-off-by: Michael Krufky <mkrufky@m1k.net>
Acked-by: Mauro Carvalho Chehab <mchehab@brturbo.com.br>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Two trivial text changes in Kconfig and lgdt330x.c
Signed-off-by: Michael Krufky <mkrufky@m1k.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Added pci_request_regions() before using the controller to avoid duplicate
usage of the I2O controller when the dpt_i2o driver and I2O subsystem is
loaded at the same time.
Signed-off-by: Markus Lidel <Markus.Lidel@shadowconnect.com>
Cc: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
From: Dave Johnson <djohnson+linux-kernel@sw.starentnetworks.com>
sendmsg()/recvmsg() syscalls from o32/n32 apps to a 64bit kernel will
cause a kernel memory leak if iov_len > UIO_FASTIOV for each syscall!
This is because both sys_sendmsg() and verify_compat_iovec() kmalloc a
new iovec structure. Only the one from sys_sendmsg() is free'ed.
I wrote a simple test program to confirm this after identifying the
problem:
http://davej.org/programs/testsendmsg.c
Note that the below fix will break solaris_sendmsg()/solaris_recvmsg() as
it also calls verify_compat_iovec() but expects it to malloc internally.
[ I fixed that. -DaveM ]
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
We need to divide, not multiply. While we're here,
use NSEC_PER_USEC instead of a magic constant.
Based upon a report from Josip Loncaric and a patch
by Andrew Morton.
Signed-off-by: David S. Miller <davem@davemloft.net>
The driver already depends on CONFIG_PCI in Kconfig.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
envctrl currently uses very odd ways to stop a thread, using various
things that should be exposed to drivers at all.
This patch (which is untested as I don't have sparc hardware) switches
it to use the proper kthread infrastructure.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Remove new configuration API from i2o_config
The API-patch is still available from the I2O website (which is mentioned in
the kernel config now). It is removed because it creates a new binary
sysfs-attribute, which doesn't have the limitiation of 4k. Expect for the
Adaptec controllers, which has a limitation in the hardware this attribute
doesn't make sense anywhere else. Until the sysfs API provides an attribute
which doesn't buffer (like firmware) and let access to at least 64k blocks i
provide a separate patch...
(akpm: basically, this API was introduced post-2.6.12 and Markus wants to pull
it out before 2.6.13).
Signed-off-by: Markus Lidel <Markus.Lidel@shadowconnect.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fixed problems so we can build with gcc-4.0.1
Signed-off-by: Peter Schaefer-Hutter <peter.schaefer-hutter@tfk-racoms.com>
Signed-off-by: Kumar Gala <kumar.gala@freescale.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Makes dpram allocations work
* Makes non-console UART work on both 8xx and 82xx
* Fixed whitespace in files that were touched
Signed-off-by: Vitaly Bordug <vbordug@ru.mvista.com>
Signed-off-by: Pantelis Antoniou <panto@intracom.gr>
Signed-off-by: Kumar Gala <kumar.gala@freescale.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix possible cpuset_sem ABBA deadlock if 'notify_on_release' set.
For a particular usage pattern, creating and destroying cpusets fairly
frequently using notify_on_release, on a very large system, this deadlock
can be seen every few days. If you are not using the cpuset
notify_on_release feature, you will never see this deadlock.
The existing code, on task exit (or cpuset deletion) did:
get cpuset_sem
if cpuset marked notify_on_release and is ready to release:
compute cpuset path relative to /dev/cpuset mount point
call_usermodehelper() forks /sbin/cpuset_release_agent with path
drop cpuset_sem
Unfortunately, the fork in call_usermodehelper can allocate memory, and
allocating memory can require cpuset_sem, if the mems_generation values
changed in the interim. This results in an ABBA deadlock, trying to obtain
cpuset_sem when it is already held by the current task.
To fix this, I put the cpuset path (which must be computed while holding
cpuset_sem) in a temporary buffer, to be used in the call_usermodehelper
call of /sbin/cpuset_release_agent only _after_ dropping cpuset_sem.
So the new logic is:
get cpuset_sem
if cpuset marked notify_on_release and is ready to release:
compute cpuset path relative to /dev/cpuset mount point
stash path in kmalloc'd buffer
drop cpuset_sem
call_usermodehelper() forks /sbin/cpuset_release_agent with path
free path
The sharp eyed reader might notice that this patch does not contain any
calls to kmalloc. The existing code in the check_for_release() routine was
already kmalloc'ing a buffer to hold the cpuset path. In the old code, it
just held the buffer for a few lines, over the cpuset_release_agent() call
that in turn invoked call_usermodehelper(). In the new code, with the
application of this patch, it returns that buffer via the new char
**ppathbuf parameter, for later use and freeing in cpuset_release_agent(),
which is called after cpuset_sem is dropped. Whereas the old code has just
one call to cpuset_release_agent(), right in the check_for_release()
routine, the new code has three calls to cpuset_release_agent(), from the
various places that a cpuset can be released.
This patch has been build and booted on SN2, and passed a stress test that
previously hit the deadlock within a few seconds.
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
i8xx_tco.c v0.08: only "arm" the watchdog when the watchdog has been
started. (Kernel Bug 4251: system reset when battery is read and i8xx_tco
driver loaded)
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Originally From: Andrew Morton <akpm@osdl.org>
Altered By: "Salyzyn, Mark" <mark_salyzyn@adaptec.com>
There is an additional 'build fix' patch that Andrew Morton submitted on
the kernel list (I have changed out his dpr_i2o with dpt_i2o below
though).
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This removes the now unused fsnotify_unlink & fsnotify_rmdir code.
Compile tested.
Signed-off-by: John McCutchan <ttb@tentacle.dhs.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Revert commit fec59a711e, which is
breaking sparc64 that doesn't have a working pci_update_resource.
We'll re-do this after 2.6.13 when we'll do it all properly.
Fix a null dereference in module unload path.
Found by a simple modprobe icn ; rmmod icn
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
this changeset broke the "nohalt" kernel boot option.
8df5a500a3
default_idle() is looking at new variable can_do_pal_halt. However,
that variable did not get cleared upon "nohalt" boot option. Result
is that "nohalt" option is ignored until perfmon is exercised.
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
modprobe aes does not work on x86_64. i386 has a similar line, this could
be the right fix. Would be nice to have in 2.6.13 final.
Signed-off-by: Olaf Hering <olh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The memory mappings for MPC8349 USB MPH and DR modules were reversed.
Signed-off-by: Li Yang <LeoLi@freescale.com>
Signed-off-by: Jiang Bo <Tanya.jiang@freescale.com>
Signed-off-by: Kumar Gala <kumar.gala@freescale.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We have some nasty issues with 2.6.12-rc6. Any request to scan on
the lpfc or qla2xxx FC adapters will oops. What is happening is the
system is defaulting to non-transport registered targets, which
inherit the parent of the scan. On this second scan, performed by
the attribute, the parent becomes the shost instead of the rport.
The slave functions in the 2 FC adapters use starget_to_rport()
routines, which incorrectly map the shost as an rport pointer.
Additionally, this pointed out other weaknesses:
- If the target structure is torn down outside of the transport,
we have no method for it to be regenerated at the proper parent.
- We have race conditions on the target being allocated by both
the midlayer scan (parent=shost) and by the fc transport
(parent=rport).
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Here's a small patch to cleanup NETDEBUG() use in net/ipv4/ for Linux
kernel 2.6.13-rc5. Also weird use of indentation is changed in some
places.
Signed-off-by: Heikki Orsila <heikki.orsila@iki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
