Commit graph

212676 commits

Author SHA1 Message Date
David S. Miller
dff9d3c215 jump label: Add sparc64 support
Add jump label support for sparc64.

Signed-off-by: David S. Miller <davem@davemloft.net>
LKML-Reference: <3b5b071fcdb2afb7f67cacecfa78b14c740278a7.1284733808.git.jbaron@redhat.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>

[ cleaned up some formatting ]

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-09-22 16:35:09 -04:00
Jason Baron
d9f5ab7b1c jump label: x86 support
add x86 support for jump label. I'm keeping this patch separate so its clear
to arch maintainers what was required for x86 support this new feature.
Hopefully, it wouldn't be too painful for other archs.

Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <f838f49f40fbea0254036194be66dc48b598dcea.1284733808.git.jbaron@redhat.com>

[ cleaned up some formatting ]

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-09-22 16:33:03 -04:00
Jason Baron
52159d98be jump label: Convert dynamic debug to use jump labels
Convert the 'dynamic debug' infrastructure to use jump labels.

Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <b77627358cea3e27d7be4386f45f66219afb8452.1284733808.git.jbaron@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-09-22 16:31:19 -04:00
Jason Baron
8f7b50c514 jump label: Tracepoint support for jump labels
Make use of the jump label infrastructure for tracepoints.

Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <a9ba2056e2c9cf332c3c300b577463ce66ff23a8.1284733808.git.jbaron@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-09-22 16:31:01 -04:00
Jason Baron
4c3ef6d793 jump label: Add jump_label_text_reserved() to reserve jump points
Add a jump_label_text_reserved(void *start, void *end), so that other
pieces of code that want to modify kernel text, can first verify that
jump label has not reserved the instruction.

Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <06236663a3a7b1c1f13576bb9eccb6d9c17b7bfe.1284733808.git.jbaron@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-09-22 16:30:46 -04:00
Jason Baron
e0cf0cd496 jump label: Initialize workqueue tracepoints *before* they are registered
Initialize the workqueue data structures *before* they are registered
so that they are ready for callbacks.

Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <e3a3383fc370ac7086625bebe89d9480d7caf372.1284733808.git.jbaron@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-09-22 16:30:03 -04:00
Jason Baron
bf5438fca2 jump label: Base patch for jump label
base patch to implement 'jump labeling'. Based on a new 'asm goto' inline
assembly gcc mechanism, we can now branch to labels from an 'asm goto'
statment. This allows us to create a 'no-op' fastpath, which can subsequently
be patched with a jump to the slowpath code. This is useful for code which
might be rarely used, but which we'd like to be able to call, if needed.
Tracepoints are the current usecase that these are being implemented for.

Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <ee8b3595967989fdaf84e698dc7447d315ce972a.1284733808.git.jbaron@redhat.com>

[ cleaned up some formating ]

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-09-22 16:29:41 -04:00
Ollie Wild
56b49f4b8f net: Move "struct net" declaration inside the __KERNEL__ macro guard
This patch reduces namespace pollution by moving the "struct net" declaration
out of the userspace-facing portion of linux/netlink.h.  It has no impact on
the kernel.

(This came up because we have several C++ applications which use "net" as a
namespace name.)

Signed-off-by: Ollie Wild <aaw@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-22 13:21:05 -07:00
Jiri Olsa
cbdd769ab9 netfilter: nf_conntrack_defrag: check socket type before touching nodefrag flag
we need to check proper socket type within ipv4_conntrack_defrag
function before referencing the nodefrag flag.

For example the tun driver receive path produces skbs with
AF_UNSPEC socket type, and so current code is causing unwanted
fragmented packets going out.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-22 13:13:34 -07:00
Patrick McHardy
d6120b8afa netfilter: nf_nat_snmp: fix checksum calculation (v4)
Fix checksum calculation in nf_nat_snmp_basic.

Based on patches by Clark Wang <wtweeker@163.com> and
Stephen Hemminger <shemminger@vyatta.com>.

https://bugzilla.kernel.org/show_bug.cgi?id=17622

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-22 13:13:33 -07:00
Eric Dumazet
15cdeadaa5 netfilter: fix a race in nf_ct_ext_create()
As soon as rcu_read_unlock() is called, there is no guarantee current
thread can safely derefence t pointer, rcu protected.

Fix is to copy t->alloc_size in a temporary variable.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-22 13:13:33 -07:00
Changli Gao
b46ffb8545 netfilter: fix ipt_REJECT TCP RST routing for indev == outdev
ip_route_me_harder can't create the route cache when the outdev is the same
with the indev for the skbs whichout a valid protocol set.

__mkroute_input functions has this check:
1998         if (skb->protocol != htons(ETH_P_IP)) {
1999                 /* Not IP (i.e. ARP). Do not create route, if it is
2000                  * invalid for proxy arp. DNAT routes are always valid.
2001                  *
2002                  * Proxy arp feature have been extended to allow, ARP
2003                  * replies back to the same interface, to support
2004                  * Private VLAN switch technologies. See arp.c.
2005                  */
2006                 if (out_dev == in_dev &&
2007                     IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
2008                         err = -EINVAL;
2009                         goto cleanup;
2010                 }
2011         }

This patch gives the new skb a valid protocol to bypass this check. In order
to make ipt_REJECT work with bridges, you also need to enable ip_forward.

This patch also fixes a regression. When we used skb_copy_expand(), we
didn't have this issue stated above, as the protocol was properly set.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-22 13:13:32 -07:00
Simon Horman
7874896a26 netfilter: nf_ct_sip: default to NF_ACCEPT in sip_help_tcp()
I initially noticed this because of the compiler warning below, but it
does seem to be a valid concern in the case where ct_sip_get_header()
returns 0 in the first iteration of the while loop.

net/netfilter/nf_conntrack_sip.c: In function 'sip_help_tcp':
net/netfilter/nf_conntrack_sip.c:1379: warning: 'ret' may be used uninitialized in this function

Signed-off-by: Simon Horman <horms@verge.net.au>
[Patrick: changed NF_DROP to NF_ACCEPT]
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-22 13:13:32 -07:00
Eric Dumazet
d485d500cf netfilter: tproxy: nf_tproxy_assign_sock() can handle tw sockets
transparent field of a socket is either inet_twsk(sk)->tw_transparent
for timewait sockets, or inet_sk(sk)->transparent for other sockets
(TCP/UDP).

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-22 13:13:31 -07:00
Linus Torvalds
c79bd89282 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6:
  sparc: Prevent no-handler signal syscall restart recursion.
  sparc: Don't mask signal when we can't setup signal frame.
  sparc64: Fix race in signal instruction flushing.
  sparc64: Support RAW perf events.
2010-09-22 12:09:46 -07:00
Mark Brown
0077ca0b5c ASoC: Fix multi-componentism
Spot the build testing.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2010-09-22 18:47:40 +01:00
Ingo Molnar
90edf27fb8 Merge branch 'linus' into perf/core
Conflicts:
	kernel/hw_breakpoint.c

Merge reason: resolve the conflict.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-22 18:45:01 +02:00
Al Viro
9a81c16b52 powerpc: fix double syscall restarts
Make sigreturn zero regs->trap, make do_signal() do the same on all
paths.  As it is, signal interrupting e.g. read() from fd 512 (==
ERESTARTSYS) with another signal getting unblocked when the first
handler finishes will lead to restart one insn earlier than it ought
to.  Same for multiple signals with in-kernel handlers interrupting
that sucker at the same time.  Same for multiple signals of any kind
interrupting that sucker on 64bit...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-09-22 09:33:50 -07:00
Linus Torvalds
b68e9d4581 Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  bdi: Fix warnings in __mark_inode_dirty for /dev/zero and friends
  char: Mark /dev/zero and /dev/kmem as not capable of writeback
  bdi: Initialize noop_backing_dev_info properly
  cfq-iosched: fix a kernel OOPs when usb key is inserted
  block: fix blk_rq_map_kern bio direction flag
  cciss: freeing uninitialized data on error path
2010-09-22 09:12:37 -07:00
Michael S. Tsirkin
5786aee8bf vhost: fix log ctx signalling
The log eventfd signalling got put in dead code.
We didn't notice because qemu currently does polling
instead of eventfd select.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-09-22 16:21:33 +02:00
Dimitris Papastamos
d47372e852 ASoC: Fix soc-cache buffer overflow bug
Make sure we stay within the cache boundaries when updating the
register cache.

Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2010-09-22 12:01:05 +01:00
Erik J. Staab
0873a5ae74 ALSA: oxygen: fix analog capture on Claro halo cards
On the HT-Omega Claro halo card, the ADC data must be captured from the
second I2S input.  Using the default first input, which isn't connected
to anything, would result in silence.

Signed-off-by: Erik J. Staab <ejs@insightbb.com>
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2010-09-22 10:04:08 +02:00
Jan Kara
692ebd17c2 bdi: Fix warnings in __mark_inode_dirty for /dev/zero and friends
Inodes of devices such as /dev/zero can get dirty for example via
utime(2) syscall or due to atime update. Backing device of such inodes
(zero_bdi, etc.) is however unable to handle dirty inodes and thus
__mark_inode_dirty complains.  In fact, inode should be rather dirtied
against backing device of the filesystem holding it. This is generally a
good rule except for filesystems such as 'bdev' or 'mtd_inodefs'. Inodes
in these pseudofilesystems are referenced from ordinary filesystem
inodes and carry mapping with real data of the device. Thus for these
inodes we have to use inode->i_mapping->backing_dev_info as we did so
far. We distinguish these filesystems by checking whether sb->s_bdi
points to a non-trivial backing device or not.

Example: Assume we have an ext3 filesystem on /dev/sda1 mounted on /.
There's a device inode A described by a path "/dev/sdb" on this
filesystem. This inode will be dirtied against backing device "8:0"
after this patch. bdev filesystem contains block device inode B coupled
with our inode A. When someone modifies a page of /dev/sdb, it's B that
gets dirtied and the dirtying happens against the backing device "8:16".
Thus both inodes get filed to a correct bdi list.

Cc: stable@kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-22 09:48:47 +02:00
Jan Kara
371d217ee1 char: Mark /dev/zero and /dev/kmem as not capable of writeback
These devices don't do any writeback but their device inodes still can get
dirty so mark bdi appropriately so that bdi code does the right thing and files
inodes to lists of bdi carrying the device inodes.

Cc: stable@kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-22 09:48:47 +02:00
Jan Kara
976e48f8a5 bdi: Initialize noop_backing_dev_info properly
Properly initialize this backing dev info so that writeback code does not
barf when getting to it e.g. via sb->s_bdi.

Cc: stable@kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-22 09:48:47 +02:00
David S. Miller
c278525978 sparc: Prevent no-handler signal syscall restart recursion.
Explicitly clear the "in-syscall" bit when we have no signal
handler and back up the program counters to back up the system
call.

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-21 22:30:13 -07:00
David S. Miller
392c21802e sparc: Don't mask signal when we can't setup signal frame.
Don't invoke the signal handler tracehook in that situation
either.

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-21 21:41:12 -07:00
Francisco Jerez
0fbecd400d drm/ttm: Clear the ghost cpu_writers flag on ttm_buffer_object_transfer.
It makes sense for a BO to move after a process has requested
exclusive RW access on it (e.g. because the BO used to be located in
unmappable VRAM and we intercepted the CPU access from the fault
handler).

If we let the ghost object inherit cpu_writers from the original
object, ttm_bo_release_list() will raise a kernel BUG when the ghost
object is destroyed. This can be reproduced with the nouveau driver on
nv5x.

Reported-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
Tested-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Signed-off-by: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2010-09-22 12:40:38 +10:00
Dave Airlie
5222454cf9 drm/radeon: don't allow device to be opened if powered down
If the switcheroo has switched the device off, don't let X open it.

Signed-off-by: Dave Airlie <airlied@redhat.com>
2010-09-22 12:32:46 +10:00
Linus Torvalds
62f1b494d8 Merge branch 'for-linus/i2c/2636-rc5' of git://git.fluff.org/bjdooks/linux
* 'for-linus/i2c/2636-rc5' of git://git.fluff.org/bjdooks/linux:
  i2c-omap: Make sure i2c bus is free before setting it to idle
2010-09-21 18:21:05 -07:00
Sage Weil
8b15575cae fs: {lock,unlock}_flocks() stubs to prepare for BKL removal
The lock structs are currently protected by the BKL, but are accessed by
code in fs/locks.c and misc file system and DLM code.  These stubs will
allow all users to switch to the new interface before the implementation
is changed to a spinlock.

Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-09-21 17:27:44 -07:00
Mathias Nyman
5c64eb26ed i2c-omap: Make sure i2c bus is free before setting it to idle
If the i2c bus receives an interrupt with both BB (bus busy) and
ARDY (register access ready) statuses set during the tranfer of the last message
the bus was put to idle while still busy.

This caused bus to timeout.

Signed-off-by: Mathias Nyman <mathias.nyman@nokia.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2010-09-22 01:06:58 +01:00
Eric Dumazet
3d13008e73 ip: fix truesize mismatch in ip fragmentation
Special care should be taken when slow path is hit in ip_fragment() :

When walking through frags, we transfert truesize ownership from skb to
frags. Then if we hit a slow_path condition, we must undo this or risk
uncharging frags->truesize twice, and in the end, having negative socket
sk_wmem_alloc counter, or even freeing socket sooner than expected.

Many thanks to Nick Bowler, who provided a very clean bug report and
test program.

Thanks to Jarek for reviewing my first patch and providing a V2

While Nick bisection pointed to commit 2b85a34e91 (net: No more
expensive sock_hold()/sock_put() on each tx), underlying bug is older
(2.6.12-rc5)

A side effect is to extend work done in commit b2722b1c3a
(ip_fragment: also adjust skb->truesize for packets not owned by a
socket) to ipv6 as well.

Reported-and-bisected-by: Nick Bowler <nbowler@elliptictech.com>
Tested-by: Nick Bowler <nbowler@elliptictech.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Jarek Poplawski <jarkao2@gmail.com>
CC: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-21 15:05:50 -07:00
Adam Jackson
eecfd57f64 intel-iommu: Use symbolic values instead of magic numbers in Lenovo w/a
Commit 9eecabcb9a ("intel-iommu: Abort 
IOMMU setup for igfx if BIOS gave no shadow GTT space") uses a bunch of 
magic numbers. Provide #defines for those to make it look slightly saner.

Signed-off-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2010-09-21 22:35:28 +01:00
David Woodhouse
9eecabcb9a intel-iommu: Abort IOMMU setup for igfx if BIOS gave no shadow GTT space
Yet another BIOS bug; Lenovo this time (X201). Red Hat bug #593516.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2010-09-21 22:28:23 +01:00
Linus Torvalds
1ce1e41c1b Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: Fix nohz balance kick
  sched: Fix user time incorrectly accounted as system time on 32-bit
2010-09-21 13:22:10 -07:00
Linus Torvalds
87ac6fa26e Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  hw breakpoints: Fix pid namespace bug
  x86: Fix instruction breakpoint encoding
  oprofile: Add Support for Intel CPU Family 6 / Model 22 (Intel Celeron 540)
  kprobes: Fix Kconfig dependency
2010-09-21 13:21:42 -07:00
Eric Dumazet
7e96dc7045 netxen: dont set skb->truesize
skb->truesize is set in core network.

Dont change it unless dealing with fragments.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-21 13:04:04 -07:00
Eric Dumazet
8df8fd2712 qlcnic: dont set skb->truesize
skb->truesize is set in core network.

Dont change it unless dealing with fragments.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-21 13:03:24 -07:00
David S. Miller
2d813760d7 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-2.6 2010-09-21 12:26:07 -07:00
Linus Torvalds
19746cad00 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  ceph: select CRYPTO
  ceph: check mapping to determine if FILE_CACHE cap is used
  ceph: only send one flushsnap per cap_snap per mds session
  ceph: fix cap_snap and realm split
  ceph: stop sending FLUSHSNAPs when we hit a dirty capsnap
  ceph: correctly set 'follows' in flushsnap messages
  ceph: fix dn offset during readdir_prepopulate
  ceph: fix file offset wrapping at 4GB on 32-bit archs
  ceph: fix reconnect encoding for old servers
  ceph: fix pagelist kunmap tail
  ceph: fix null pointer deref on anon root dentry release
2010-09-21 11:20:10 -07:00
Linus Torvalds
0ffe37de76 Merge branch 'drm-intel-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ickle/drm-intel
* 'drm-intel-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ickle/drm-intel:
  drm/i915: Hold a reference to the object whilst unbinding the eviction list
  drm/i915,agp/intel: Add second set of PCI-IDs for B43
  drm/i915: Fix Sandybridge fence registers
  drm/i915/crt: Downgrade warnings for hotplug failures
  drm/i915: Ensure that the crtcinfo is populated during mode_fixup()
2010-09-21 11:00:30 -07:00
Linus Torvalds
4e24db5b1a Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  lguest: update comments to reflect LHCALL_LOAD_GDT_ENTRY.
  virtio: console: Prevent userspace from submitting NULL buffers
  virtio: console: Fix poll blocking even though there is data to read
2010-09-21 11:00:09 -07:00
Yinghai Lu
74b3c444a9 x86, setup: Fix earlyprintk=serial,0x3f8,115200
earlyprintk can take and I/O port, so we need to handle this case in
the setup code too, otherwise 0x3f8 will be treated as a baud rate.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <4C7B05A6.4010801@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-09-21 10:18:33 -07:00
Yinghai Lu
83d9f65bda x86, setup: Fix earlyprintk=serial,ttyS0,115200
Torsten reported that there is garbage output,
after commit 8fee13a48e (x86,
setup: enable early console output from the decompressor)

It turns out we missed the offset for that case.

Reported-by: Torsten Kaiser <just.for.lkml@googlemail.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <4C7B0578.8090807@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-09-21 10:18:14 -07:00
Steven Rostedt
a8027073eb tracing/sched: Add sched_pi_setprio tracepoint
Add a tracepoint that shows the priority of a task being boosted
via priority inheritance.

Cc: Gregory Haskins <ghaskins@novell.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-09-21 10:56:41 -04:00
Steven Rostedt
b3bc211cfe sched: Give CPU bound RT tasks preference
If a high priority task is waking up on a CPU that is running a
lower priority task that is bound to a CPU, see if we can move the
high RT task to another CPU first. Note, if all other CPUs are
running higher priority tasks than the CPU bounded current task,
then it will be preempted regardless.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Gregory Haskins <ghaskins@novell.com>
LKML-Reference: <20100921024138.888922071@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-21 13:57:12 +02:00
Steven Rostedt
43fa5460fe sched: Try not to migrate higher priority RT tasks
When first working on the RT scheduler design, we concentrated on
keeping all CPUs running RT tasks instead of having multiple RT
tasks on a single CPU waiting for the migration thread to move
them. Instead we take a more proactive stance and push or pull RT
tasks from one CPU to another on wakeup or scheduling.

When an RT task wakes up on a CPU that is running another RT task,
instead of preempting it and killing the cache of the running RT
task, we look to see if we can migrate the RT task that is waking
up, even if the RT task waking up is of higher priority.

This may sound a bit odd, but RT tasks should be limited in
migration by the user anyway. But in practice, people do not do
this, which causes high prio RT tasks to bounce around the CPUs.
This becomes even worse when we have priority inheritance, because
a high prio task can block on a lower prio task and boost its
priority. When the lower prio task wakes up the high prio task, if
it happens to be on the same CPU it will migrate off of it.

But in reality, the above does not happen much either, because the
wake up of the lower prio task, which has already been boosted, if
it was on the same CPU as the higher prio task, it would then
migrate off of it. But anyway, we do not want to migrate them
either.

To examine the scheduling, I created a test program and examined it
under kernelshark. The test program created CPU * 2 threads, where
each thread had a different priority. The program takes different
options. The options used in this change log was to have priority
inheritance mutexes or not.

All threads did the following loop:

static void grab_lock(long id, int iter, int l)
{
	ftrace_write("thread %ld iter %d, taking lock %d\n",
		     id, iter, l);
	pthread_mutex_lock(&locks[l]);
	ftrace_write("thread %ld iter %d, took lock %d\n",
		     id, iter, l);
	busy_loop(nr_tasks - id);
	ftrace_write("thread %ld iter %d, unlock lock %d\n",
		     id, iter, l);
	pthread_mutex_unlock(&locks[l]);
}

void *start_task(void *id)
{
	[...]
	while (!done) {
		for (l = 0; l < nr_locks; l++) {
			grab_lock(id, i, l);
			ftrace_write("thread %ld iter %d sleeping\n",
				     id, i);
			ms_sleep(id);
		}
		i++;
	}
	[...]
}

The busy_loop(ms) keeps the CPU spinning for ms milliseconds. The
ms_sleep(ms) sleeps for ms milliseconds. The ftrace_write() writes
to the ftrace buffer to help analyze via ftrace.

The higher the id, the higher the prio, the shorter it does the
busy loop, but the longer it spins. This is usually the case with
RT tasks, the lower priority tasks usually run longer than higher
priority tasks.

At the end of the test, it records the number of loops each thread
took, as well as the number of voluntary preemptions, non-voluntary
preemptions, and number of migrations each thread took, taking the
information from /proc/$$/sched and /proc/$$/status.

Running this on a 4 CPU processor, the results without changes to
the kernel looked like this:

Task        vol    nonvol   migrated     iterations
----        ---    ------   --------     ----------
  0:         53      3220       1470             98
  1:        562       773        724             98
  2:        752       933       1375             98
  3:        749        39        697             98
  4:        758         5        515             98
  5:        764         2        679             99
  6:        761         2        535             99
  7:        757         3        346             99

total:     5156       4977      6341            787

Each thread regardless of priority migrated a few hundred times.
The higher priority tasks, were a little better but still took
quite an impact.

By letting higher priority tasks bump the lower prio task from the
CPU, things changed a bit:

Task        vol    nonvol   migrated     iterations
----        ---    ------   --------     ----------
  0:         37      2835       1937             98
  1:        666      1821       1865             98
  2:        654      1003       1385             98
  3:        664       635        973             99
  4:        698       197        352             99
  5:        703       101        159             99
  6:        708         1         75             99
  7:        713         1          2             99

total:     4843       6594      6748            789

The total # of migrations did not change (several runs showed the
difference all within the noise). But we now see a dramatic
improvement to the higher priority tasks. (kernelshark showed that
the watchdog timer bumped the highest priority task to give it the
2 count. This was actually consistent with every run).

Notice that the # of iterations did not change either.

The above was with priority inheritance mutexes. That is, when the
higher prority task blocked on a lower priority task, the lower
priority task would inherit the higher priority task (which shows
why task 6 was bumped so many times). When not using priority
inheritance mutexes, the current kernel shows this:

Task        vol    nonvol   migrated     iterations
----        ---    ------   --------     ----------
  0:         56      3101       1892             95
  1:        594       713        937             95
  2:        625       188        618             95
  3:        628         4        491             96
  4:        640         7        468             96
  5:        631         2        501             96
  6:        641         1        466             96
  7:        643         2        497             96

total:     4458       4018      5870            765

Not much changed with or without priority inheritance mutexes. But
if we let the high priority task bump lower priority tasks on
wakeup we see:

Task        vol    nonvol   migrated     iterations
----        ---    ------   --------     ----------
  0:        115      3439       2782             98
  1:        633      1354       1583             99
  2:        652       919       1218             99
  3:        645       713        934             99
  4:        690         3          3             99
  5:        694         1          4             99
  6:        720         3          4             99
  7:        747         0          1            100

Which shows a even bigger change. The big difference between task 3
and task 4 is because we have only 4 CPUs on the machine, causing
the 4 highest prio tasks to always have preference.

Although I did not measure cache misses, and I'm sure there would
be little to measure since the test was not data intensive, I could
imagine large improvements for higher priority tasks when dealing
with lower priority tasks. Thus, I'm satisfied with making the
change and agreeing with what Gregory Haskins argued a few years
ago when we first had this discussion.

One final note. All tasks in the above tests were RT tasks. Any RT
task will always preempt a non RT task that is running on the CPU
the RT task wants to run on.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Gregory Haskins <ghaskins@novell.com>
LKML-Reference: <20100921024138.605460343@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-21 13:57:12 +02:00
Venkatesh Pallipadi
58b26c4c02 sched: Increment cache_nice_tries only on periodic lb
scheduler uses cache_nice_tries as an indicator to do cache_hot and
active load balance, when normal load balance fails. Currently,
this value is changed on any failed load balance attempt. That ends
up being not so nice to workloads that enter/exit idle often, as
they do more frequent new_idle balance and that pretty soon results
in cache hot tasks being pulled in.

Making the cache_nice_tries ignore failed new_idle balance seems to
make better sense. With that only the failed load balance in
periodic load balance gets accounted and the rate of accumulation
of cache_nice_tries will not depend on idle entry/exit (short
running sleep-wakeup kind of tasks). This reduces movement of
cache_hot tasks.

schedstat diff (after-before) excerpt from a workload that has
frequent and short wakeup-idle pattern (:2 in cpu col below refers
to NEWIDLE idx) This snapshot was across ~400 seconds.

Without this change:
domainstats:  domain0
 cpu     cnt      bln      fld      imb     gain    hgain  nobusyq  nobusyg
 0:2  306487   219575    73167  110069413    44583    19070     1172   218403
 1:2  292139   194853    81421  120893383    50745    21902     1259   193594
 2:2  283166   174607    91359  129699642    54931    23688     1287   173320
 3:2  273998   161788    93991  132757146    57122    24351     1366   160422
 4:2  289851   215692    62190  83398383    36377    13680      851   214841
 5:2  316312   222146    77605  117582154    49948    20281      988   221158
 6:2  297172   195596    83623  122133390    52801    21301      929   194667
 7:2  283391   178078    86378  126622761    55122    22239      928   177150
 8:2  297655   210359    72995  110246694    45798    19777     1125   209234
 9:2  297357   202011    79363  119753474    50953    22088     1089   200922
10:2  278797   178703    83180  122514385    52969    22726     1128   177575
11:2  272661   167669    86978  127342327    55857    24342     1195   166474
12:2  293039   204031    73211  110282059    47285    19651      948   203083
13:2  289502   196762    76803  114712942    49339    20547     1016   195746
14:2  264446   169609    78292  115715605    50459    21017      982   168627
15:2  260968   163660    80142  116811793    51483    21281     1064   162596

With this change:
domainstats:  domain0
 cpu     cnt      bln      fld      imb     gain    hgain  nobusyq  nobusyg
 0:2  272347   187380    77455  105420270    24975        1      953   186427
 1:2  267276   172360    86234  116242264    28087        6     1028   171332
 2:2  259769   156777    93281  123243134    30555        1     1043   155734
 3:2  250870   143129    97627  127370868    32026        6     1188   141941
 4:2  248422   177116    64096  78261112    22202        2      757   176359
 5:2  275595   180683    84950  116075022    29400        6      778   179905
 6:2  262418   162609    88944  119256898    31056        4      817   161792
 7:2  252204   147946    92646  122388300    32879        4      824   147122
 8:2  262335   172239    81631  110477214    26599        4      864   171375
 9:2  261563   164775    88016  117203621    28331        3      849   163926
10:2  243389   140949    93379  121353071    29585        2      909   140040
11:2  242795   134651    98310  124768957    30895        2     1016   133635
12:2  255234   166622    79843  104696912    26483        4      746   165876
13:2  244944   151595    83855  109808099    27787        3      801   150794
14:2  241301   140982    89935  116954383    30403        6      845   140137
15:2  232271   128564    92821  119185207    31207        4     1416   127148

Signed-off-by: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1284167957-3675-1-git-send-email-venki@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-21 13:57:11 +02:00
Ingo Molnar
cf84fd9632 Merge commit 'v2.6.36-rc5' into sched/core
Merge reason: Pick up the latest fixes in -rc5.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-21 13:56:49 +02:00