Apparently some systems export valid HPET addresses, but hpet_enable()
fails. Then when the HPET clocksource starts up, it only checks for a
valid HPET address, and the result is a system where time does not advance.
See http://bugme.osdl.org/show_bug.cgi?id=7062 for details.
This patch just makes sure we better check that the HPET is functional
before registering the HPET clocksource.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix receive tty error handling in synclink_gt driver. Adrian reported
compiler warning for incorrect bit test against char variable. I
determined these and other device specific error bits were incorrectly
defined.
Signed-off-by: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We need to be careful when referencing mirrors[i].rdev. It can disappear
under us at various times.
So:
fix a couple of problem places.
comment a couple of non-problem places
move an 'atomic_add' which deferences rdev down a little
way to some where where it is sure to not be NULL.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The ZVC counter update threshold is currently set to a fixed value of 32.
This patch sets up the threshold depending on the number of processors and
the sizes of the zones in the system.
With the current threshold of 32, I was able to observe slight contention
when more than 130-140 processors concurrently updated the counters. The
contention vanished when I either increased the threshold to 64 or used
Andrew's idea of overstepping the interval (see ZVC overstep patch).
However, we saw contention again at 220-230 processors. So we need higher
values for larger systems.
But the current default is already a bit of an overkill for smaller
systems. Some systems have tiny zones where precision matters. For
example i386 and x86_64 have 16M DMA zones and either 900M ZONE_NORMAL or
ZONE_DMA32. These are even present on SMP and NUMA systems.
The patch here sets up a threshold based on the number of processors in the
system and the size of the zone that these counters are used for. The
threshold should grow logarithmically, so we use fls() as an easy
approximation.
Results of tests on a system with 1024 processors (4TB RAM)
The following output is from a test allocating 1GB of memory concurrently
on each processor (Forking the process. So contention on mmap_sem and the
pte locks is not a factor):
X MIN
TYPE: CPUS WALL WALL SYS USER TOTCPU
fork 1 0.552 0.552 0.540 0.012 0.552
fork 4 0.552 0.548 2.164 0.036 2.200
fork 16 0.564 0.548 8.812 0.164 8.976
fork 128 0.580 0.572 72.204 1.208 73.412
fork 256 1.300 0.660 310.400 2.160 312.560
fork 512 3.512 0.696 1526.836 4.816 1531.652
fork 1020 20.024 0.700 17243.176 6.688 17249.863
So a threshold of 32 is fine up to 128 processors. At 256 processors contention
becomes a factor.
Overstepping the counter (earlier patch) improves the numbers a bit:
fork 4 0.552 0.548 2.164 0.040 2.204
fork 16 0.552 0.548 8.640 0.148 8.788
fork 128 0.556 0.548 69.676 0.956 70.632
fork 256 0.876 0.636 212.468 2.108 214.576
fork 512 2.276 0.672 997.324 4.260 1001.584
fork 1020 13.564 0.680 11586.436 6.088 11592.523
Still contention at 512 and 1020. Contention at 1020 is down by a third.
256 still has a slight bit of contention.
After this patch the counter threshold will be set to 125 which reduces
contention significantly:
fork 128 0.560 0.548 69.776 0.932 70.708
fork 256 0.636 0.556 143.460 2.036 145.496
fork 512 0.640 0.548 284.244 4.236 288.480
fork 1020 1.500 0.588 1326.152 8.892 1335.044
[akpm@osdl.org: !SMP build fix]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Increments and decrements are usually grouped rather than mixed. We can
optimize the inc and dec functions for that case.
Increment and decrement the counters by 50% more than the threshold in
those cases and set the differential accordingly. This decreases the need
to update the atomic counters.
The idea came originally from Andrew Morton. The overstepping alone was
sufficient to address the contention issue found when updating the global
and the per zone counters from 160 processors.
Also remove some code in dec_zone_page_state.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When skipping to the last TD of an URB, go to the _last_ entry in the
list instead of the _first_ entry (as780). This fixes Bugzilla #6747
and possibly others.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Patch to add VIA PCI quirk for Enhanced/Extended USB on VT8235
southbridge. It is needed in order to use EHCI/USB 2.0 with ACPI.
Without it IRQs are not routed correctly, you get an "Unlink after
no-IRQ?" error and the device is unusable.
I belive this could also be a fix for Bugzilla Bug 5835.
Signed-off-by: Mark Hindley <mark@hindley.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This entry was sent in by Emmanuel Vasilakis <evas@forthnet.gr>, turned
into a patch by yours truly.
Signed-off-by: Phil Dibowitz <phil@ipom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch removes the Kyocera Finecam L3 entry in unusual devices
originally submitted by Michael Krauth <michael.krauth@web.de> and
Alessandro Fracchetti <al.fracchetti@tin.it> given that Gerriet
<ger.haw@gmx.de> finds he doesn't need it and Alessandro confirms it
isn't needed anymore as well.
Signed-off-by: Phil Dibowitz <phil@ipom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Unlike other sorts of endpoint queues, Isochronous queues don't stop
when an error is encountered. This patch (as772) fixes the scanning
routine in uhci-hcd, to make it keep on going when it finds an Iso
error.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The new spinlock debug code turned up a spinlock recursion bug in the
Ethernet gadget driver on a disconnect path; it would show up with any
UDC driver where the cancellation of active requests was synchronous,
rather than e.g. delayed until a controller's completion IRQ.
That recursion is fixed here by creating and using a new spinlock to
protect the relevant lists.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Adds all GTCO CalComp Digitizers and InterWrite School Products to
hid-core.c blacklist.
Signed-off-by: Jeremy A. Roberson <jroberson@gtcocalcomp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
It is supposed to be OK to call mthca_create_ah() and mthca_destroy_ah()
from any context. However, for mem-full HCAs, these functions use the
mthca_alloc() and mthca_free() bitmap helpers, and those helpers use
non-IRQ-safe spin_lock() internally. Lockdep correctly warns that
this could lead to a deadlock. Fix this by changing mthca_alloc() and
mthca_free() to use spin_lock_irqsave().
Signed-off-by: Roland Dreier <rolandd@cisco.com>
When I tested Linux kernel 2.6.17.7 about statistics
"ipFragFails",found that this counter couldn't increase correctly. The
criteria is RFC2011:
RFC2011
ipFragFails OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of IP datagrams that have been discarded because
they needed to be fragmented at this entity but could not
be, e.g., because their Don't Fragment flag was set."
::= { ip 18 }
When I send big IP packet to a router with DF bit set to 1 which need to
be fragmented, and router just sends an ICMP error message
ICMP_FRAG_NEEDED but no increments for this counter(in the function
ip_fragment).
Signed-off-by: Wei Dong <weid@nanjing-fnst.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch limits the warning messages when socket allocation failures
happen. It happens under memory pressure.
Signed-off-by: Akinobu Mita <mita@miraclelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 8c74932779 ("i386: Remove
alternative_smp") did not actually compile on x86 with CONFIG_SMP.
This fixes the __build_read/write_lock helpers. I've boot tested on
SMP.
[ Andi: "Oops, I think that was a quilt unrefreshed patch. Sorry. I
fixed those before testing, but then still send out the old patch." ]
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Gerd Hoffmann <kraxel@suse.de>
Acked-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Patch from Ben Dooks
Cleanup for include/asm-arma/arch-s3c2410/dma.h,
by using tab characters to indent items, remove the
now un-necessary changelog, and update the copyright
information.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Ben Dooks
The type naming in the s3c24xx dma code is riddled with
typedefs creating _t types, from the code import from 2.4
which is contrary to the current Kernel coding style.
This patch cleans this up, removing the typedefs and
and fixing up the resultant code changes.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
john stultz
Paul Fulghum
NeilBrown
Christoph Lameter
Linus Torvalds
Alan Stern
Nobuhiro Iwamatsu
Mark Hindley
Andrew Morton
Phil Dibowitz
David Brownell
Ping Cheng
Jeremy Roberson
juergen.mell@t-online.de
Roland Dreier
Wei Dong
Akinobu Mita
YOSHIFUJI Hideaki
Chris Wright
Ben Dooks