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691,473 commits

Author SHA1 Message Date
Frederic Bohe
2856922c15 Ext4: Fix online resize block group descriptor corruption
This is the patch for the group descriptor table corruption during
online resize pointed out by Theodore Tso.  The problem was caused by
the fact that the ext4 group descriptor can be either 32 or 64 bytes
long.  Only the 64 bytes structure was taken into account.

Signed-off-by: Frederic Bohe <frederic.bohe@bull.net>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-06-20 11:48:48 -04:00
Oleg Nesterov
ea71a54670 sched: refactor wait_for_completion_timeout()
Simplify the code and fix the boundary condition of
wait_for_completion_timeout(,0).

We can kill the first __remove_wait_queue() as well.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2008-06-20 17:15:49 +02:00
Johannes Berg
0f476b6d91 softirq: remove irqs_disabled warning from local_bh_enable
There's no need to use local_irq_save() over local_irq_disable() in the
local_bh_enable code since it is a bug to call it with irqs disabled and
do_softirq will enable irqs if there is any pending work.

Consolidate the code from local_bh_enable and ..._ip to avoid having a
disconnect between them in the warnings they trigger that is currently
there.

Also always trigger the warning on in_irq(), not just in the
trace-irqflags case.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Michael Buesch <mb@bu3sch.de>
Cc: David Ellingsworth <david@identd.dyndns.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-20 15:45:29 +02:00
Ingo Molnar
a1d5a8691f x86: unify __set_fixmap, fix
fix build failure:

 arch/x86/mm/pgtable.c:280: warning: ‘enum fixed_addresses’ declared inside parameter list
 arch/x86/mm/pgtable.c:280: warning: its scope is only this definition or declaration, which is probably not what you want
 arch/x86/mm/pgtable.c:280: error: parameter 1 (‘idx’) has incomplete type

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-20 15:36:57 +02:00
Jeremy Fitzhardinge
aeaaa59c7e x86/paravirt/xen: add set_fixmap pv_mmu_ops
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-20 15:09:56 +02:00
Jeremy Fitzhardinge
d494a96125 x86: implement set_pte_vaddr
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-20 15:09:54 +02:00
Jeremy Fitzhardinge
7c7e6e07e2 x86: unify __set_fixmap
In both cases, I went with the 32-bit behaviour.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-20 15:09:51 +02:00
Jeremy Fitzhardinge
944256e00a x86: unify asm-x86/fixmap*.h
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-20 15:09:49 +02:00
Jeremy Fitzhardinge
ebb9cfe20f xen: don't drop NX bit
Because NX is now enforced properly, we must put the hypercall page
into the .text segment so that it is executable.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
Cc: the arch/x86 maintainers <x86@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-20 14:56:41 +02:00
Jeremy Fitzhardinge
05345b0f00 xen: mask unwanted pte bits in __supported_pte_mask
[ Stable: this isn't a bugfix in itself, but it's a pre-requiste
  for "xen: don't drop NX bit" ]

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
Cc: the arch/x86 maintainers <x86@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-20 14:56:36 +02:00
Isaku Yamahata
4653938379 xen: Use wmb instead of rmb in xen_evtchn_do_upcall().
This patch is ported one from 534:77db69c38249 of linux-2.6.18-xen.hg.
Use wmb instead of rmb to enforce ordering between
evtchn_upcall_pending and evtchn_pending_sel stores
in xen_evtchn_do_upcall().

Cc: Samuel Thibault <samuel.thibault@eu.citrix.com>
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: the arch/x86 maintainers <x86@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-20 14:56:30 +02:00
Jeremy Fitzhardinge
a987b16cc6 xen: don't drop NX bit
Because NX is now enforced properly, we must put the hypercall page
into the .text segment so that it is executable.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
Cc: the arch/x86 maintainers <x86@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-20 14:55:13 +02:00
Jeremy Fitzhardinge
eb179e443d xen: mask unwanted pte bits in __supported_pte_mask
[ Stable: this isn't a bugfix in itself, but it's a pre-requiste
  for "xen: don't drop NX bit" ]

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
Cc: the arch/x86 maintainers <x86@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-20 14:55:11 +02:00
Isaku Yamahata
6673cf63e5 xen: Use wmb instead of rmb in xen_evtchn_do_upcall().
This patch is ported one from 534:77db69c38249 of linux-2.6.18-xen.hg.
Use wmb instead of rmb to enforce ordering between
evtchn_upcall_pending and evtchn_pending_sel stores
in xen_evtchn_do_upcall().

Cc: Samuel Thibault <samuel.thibault@eu.citrix.com>
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: the arch/x86 maintainers <x86@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-20 14:55:10 +02:00
Takashi Iwai
a1855d802f ALSA: hda - Fix digital converter proc output
AC_VERB_GET_DIGI_CONVERT_2 isn't actually implemented but reserved.
The whole SIC bits are returned from DIGI_CONVERT_1.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
2008-06-20 14:16:01 +02:00
Suresh Siddha
54481cf88b x86: fix NULL pointer deref in __switch_to
I am able to reproduce the oops reported by Simon in __switch_to() with
lguest.

My debug showed that there is at least one lguest specific
issue (which should be present in 2.6.25 and before aswell) and it got
exposed with a kernel oops with the recent fpu dynamic allocation patches.

In addition to the previous possible scenario (with fpu_counter), in the
presence of lguest, it is possible that the cpu's TS bit it still set and the
lguest launcher task's thread_info has TS_USEDFPU still set.

This is because of the way the lguest launcher handling the guest's TS bit.
(look at lguest_set_ts() in lguest_arch_run_guest()). This can result
in a DNA fault while doing unlazy_fpu() in __switch_to(). This will
end up causing a DNA fault in the context of new process thats
getting context switched in (as opossed to handling DNA fault in the context
of lguest launcher/helper process).

This is wrong in both pre and post 2.6.25 kernels. In the recent
2.6.26-rc series, this is showing up as NULL pointer dereferences or
sleeping function called from atomic context(__switch_to()), as
we free and dynamically allocate the FPU context for the newly
created threads. Older kernels might show some FPU corruption for processes
running inside of lguest.

With the appended patch, my test system is running for more than 50 mins
now. So atleast some of your oops (hopefully all!) should get fixed.
Please give it a try. I will spend more time with this fix tomorrow.

Reported-by: Simon Holm Thøgersen <odie@cs.aau.dk>
Reported-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-20 13:26:18 +02:00
Roland Dreier
bb10ed0994 sched: fix wait_for_completion_timeout() spurious failure under heavy load
It seems that the current implementaton of wait_for_completion_timeout()
has a small problem under very high load for the common pattern:

	if (!wait_for_completion_timeout(&done, timeout))
		/* handle failure */

because the implementation very roughly does (lots of code deleted to
show the basic flow):

	static inline long __sched
	do_wait_for_common(struct completion *x, long timeout, int state)
	{
		if (x->done)
			return timeout;

		do {
			timeout = schedule_timeout(timeout);

			if (!timeout)
				return timeout;

		} while (!x->done);

		return timeout;
	}

so if the system is very busy and x->done is not set when
do_wait_for_common() is entered, it is possible that the first call to
schedule_timeout() returns 0 because the task doing wait_for_completion
doesn't get rescheduled for a long time, even if it is woken up early
enough.

In this case, wait_for_completion_timeout() returns 0 without even
checking x->done again, and the code above falls into its failure case
purely for scheduler reasons, even if the hardware event or whatever was
being waited for happened early enough.

It would make sense to add an extra test to do_wait_for() in the timeout
case and return 1 if x->done is actually set.

A quick audit (not exhaustive) of wait_for_completion_timeout() callers
seems to indicate that no one actually cares about the return value in
the success case -- they just test for 0 (timed out) versus non-zero
(wait succeeded).

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-20 13:19:32 +02:00
Huang, Ying
443cd507ce lockdep: add lock_class information to lock_chain and output it
This patch records array of lock_class into lock_chain, and export
lock_chain information via /proc/lockdep_chains.

It is based on x86/master branch of git-x86 tree, and has been tested
on x86_64 platform.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-20 12:21:33 +02:00
Peter Zijlstra
8a8cde163e sched: rt: dont stop the period timer when there are tasks wanting to run
So if the group ever gets throttled, it will never wake up again.

Reported-by: "Daniel K." <dk@uw.no>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Daniel K. <dk@uw.no>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-20 11:00:19 +02:00
Peter Zijlstra
6c3df25511 sched: rt: dont stop the period timer when there are tasks wanting to run
So if the group ever gets throttled, it will never wake up again.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "Daniel K." <dk@uw.no>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reported-by: "Daniel K." <dk@uw.no>
2008-06-20 10:26:02 +02:00
Peter Zijlstra
10b612f440 sched: rt: fix the bandwidth contraint computations
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "Daniel K." <dk@uw.no>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-20 10:26:01 +02:00
Peter Zijlstra
eff6549b95 sched: rt: move some code around
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "Daniel K." <dk@uw.no>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-20 10:26:00 +02:00
Peter Zijlstra
b79f3833d8 sched: rt: fix SMP bandwidth balancing for throttled groups
Now we exceed the runtime and get throttled - the period rollover tick
will subtract the cpu quota from the runtime and check if we're below
quota. However with this cpu having a very small portion of the runtime
it will not refresh as fast as it should.

Therefore, also rebalance the runtime when we're throttled.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "Daniel K." <dk@uw.no>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-20 10:26:00 +02:00
Peter Zijlstra
ada18de2eb sched: debug: add some rt debug output
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "Daniel K." <dk@uw.no>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-20 10:25:59 +02:00
Len Brown
5a87f7f5e5 Merge branch 'bugzilla-9761' into release 2008-06-20 02:47:16 -04:00
Len Brown
7b09f27891 Merge branch 'bugzilla-10695' into release 2008-06-20 02:45:05 -04:00
Ingo Molnar
7dbceaf9bb x86, bitops: make constant-bit set/clear_bit ops faster, adapt, clean up
fix integration bug introduced by "x86: bitops take an unsigned long *"
which turned "(void *) + x" into "(long *) + x".

small cleanups to make it more apparent which value get propagated where.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-20 08:08:49 +02:00
Dave Airlie
858a3685bc drm: only trust core drm ioctls - driver ioctls are a mess.
So driver ioctls need a full auditing before we can make this change.

Signed-off-by: Dave Airlie <airlied@redhat.com>
2008-06-20 15:42:38 +10:00
Zhenyu Wang
d3adbc0c58 drm/i915: add support for Intel series 4 chipsets.
Signed-off-by: Zhenyu Wang <zhenyu.z.wang@intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2008-06-20 12:12:56 +10:00
Zhenyu Wang
7d15ddf79e [agp]: fixup chipset flush for new Intel G4x.
Signed-off-by: Zhenyu Wang <zhenyu.z.wang@intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2008-06-20 11:48:06 +10:00
Michael Chan
8427f13612 bnx2: Update driver version to 1.7.7.
And update module description.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: Benjamin Li <benli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-19 16:44:44 -07:00
Michael Chan
2739a8bb5b bnx2: Cleanup error handling in bnx2_open().
All error handling in bnx2_open() can be consolidated.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: Benjamin Li <benli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-19 16:44:10 -07:00
Michael Chan
5e9ad9e108 bnx2: Turn on multi rx rings.
Enable multiple rx rings if MSI-X vectors are available.  We enable
up to 7 rx rings.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: Benjamin Li <benli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-19 16:43:17 -07:00
Michael Chan
2dffcc3dcd bnx2: Update firmware to support multi rx rings.
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: Benjamin Li <benli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-19 16:42:39 -07:00
Michael Chan
f0ea2e6385 bnx2: Use one handler for all MSI-X vectors.
Use the same MSI-X handler to schedule NAPI.  Change the dev_instance
void pointer to the bnx2_napi struct instead so we can have the proper
context for each MSI-X vector.

Add a new bnx2_poll_msix() that is optimized for handling MSI-X
NAPI polling of rx/tx work only.  Remove the old bnx2_tx_poll() that
is no longer needed.  Each MSI-X vector handles 1 tx and 1 rx ring.
The first vector handles link events as well.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: Benjamin Li <benli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-19 16:41:57 -07:00
Michael Chan
43e80b89b6 bnx2: Optimize fast-path tx and rx work.
Add hw_tx_cons_ptr and hw_rx_cons_ptr to speed up the retreival of
the tx and rx consumer index, since the MSI-X and default status
blocks have different structures.

Combine status_blk and status_blk_msix into a union.  We'll only use
one type of status block for each vector.

Separate the code to detect more rx and tx work from the code to
detect link related work.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: Benjamin Li <benli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-19 16:41:08 -07:00
Michael Chan
bb4f98abf5 bnx2: Put rx ring variables in a separate struct.
In preparation for multi-ring support, rx ring variables are now put
in a separate bnx2_rx_ring_info struct.  With MSI-X, we can support
multiple rx rings.

The functions to allocate/free rx memory and to initialize rx rings
are now modified to handle multiple rings.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: Benjamin Li <benli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-19 16:38:19 -07:00
Michael Chan
35e9010b22 bnx2: Put tx ring variables in a separate struct.
In preparation for multi-ring support, tx ring variables are now put
in a separate bnx2_tx_ring_info struct.  Multi tx ring will not be
enabled until it is fully supported by the stack.  Only 1 tx ring
will be used at the moment.

The functions to allocate/free tx memory and to initialize tx rings
are now modified to handle multiple rings.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: Benjamin Li <benli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-19 16:37:42 -07:00
YOSHIFUJI Hideaki
f630e43a21 ipv6: Drop packets for loopback address from outside of the box.
[ Based upon original report and patch by Karsten Keil.  Karsten
  has verified that this fixes the TAHI test case "ICMPv6 test
  v6LC.5.1.2 Part F". -DaveM ]

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-19 16:33:57 -07:00
Shan Wei
aea7427f70 ipv6: Remove options header when setsockopt's optlen is 0
Remove the sticky Hop-by-Hop options header by calling setsockopt()
for IPV6_HOPOPTS with a zero option length, per RFC3542.

Routing header and Destination options header does the same as
Hop-by-Hop options header.

Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-19 16:29:39 -07:00
Ben Hutchings
4497b0763c net: Discard and warn about LRO'd skbs received for forwarding
Add skb_warn_if_lro() to test whether an skb was received with LRO and
warn if so.

Change br_forward(), ip_forward() and ip6_forward() to call it) and
discard the skb if it returns true.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-19 16:22:28 -07:00
Ben Hutchings
0187bdfb05 net: Disable LRO on devices that are forwarding
Large Receive Offload (LRO) is only appropriate for packets that are
destined for the host, and should be disabled if received packets may be
forwarded.  It can also confuse the GSO on output.

Add dev_disable_lro() function which uses the appropriate ethtool ops to
disable LRO if enabled.

Add calls to dev_disable_lro() in br_add_if() and functions that enable
IPv4 and IPv6 forwarding.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-19 16:15:47 -07:00
Vlad Yasevich
2e3216cd54 sctp: Follow security requirement of responding with 1 packet
RFC 4960, Section 11.4. Protection of Non-SCTP-Capable Hosts

When an SCTP stack receives a packet containing multiple control or
DATA chunks and the processing of the packet requires the sending of
multiple chunks in response, the sender of the response chunk(s) MUST
NOT send more than one packet.  If bundling is supported, multiple
response chunks that fit into a single packet MAY be bundled together
into one single response packet.  If bundling is not supported, then
the sender MUST NOT send more than one response chunk and MUST
discard all other responses.  Note that this rule does NOT apply to a
SACK chunk, since a SACK chunk is, in itself, a response to DATA and
a SACK does not require a response of more DATA.

We implement this by not servicing our outqueue until we reach the end
of the packet.  This enables maximum bundling.  We also identify
'response' chunks and make sure that we only send 1 packet when sending
such chunks.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-19 16:08:18 -07:00
Wei Yongjun
7115e632f9 sctp: Validate Initiate Tag when handling ICMP message
This patch add to validate initiate tag and chunk type if verification
tag is 0 when handling ICMP message.

RFC 4960, Appendix C. ICMP Handling

ICMP6) An implementation MUST validate that the Verification Tag
contained in the ICMP message matches the Verification Tag of the peer.
If the Verification Tag is not 0 and does NOT match, discard the ICMP
message.  If it is 0 and the ICMP message contains enough bytes to
verify that the chunk type is an INIT chunk and that the Initiate Tag
matches the tag of the peer, continue with ICMP7.  If the ICMP message
is too short or the chunk type or the Initiate Tag does not match,
silently discard the packet.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-19 16:07:48 -07:00
David S. Miller
0344f1c66b Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:

	net/mac80211/tx.c
2008-06-19 16:00:04 -07:00
Jan Beulich
5f0120b578 x86-64: remove unnecessary ptregs call stubs
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: "Andi Kleen" <andi@firstfloor.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-19 14:25:11 +02:00
Jordan Crouse
ffe6e1da86 x86, geode: add a VSA2 ID for General Software
General Software writes their own VSA2 module for their version
of the Geode BIOS, which returns a different ID then the standard
VSA2.  This was causing the framebuffer driver to break for most
GSW boards.

Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Cc: tglx@linutronix.de
Cc: linux-geode@lists.infradead.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-19 14:19:03 +02:00
Bharath Ravi
d4abc238c9 sched, delay accounting: fix incorrect delay time when constantly waiting on runqueue
This patch corrects the incorrect value of per process run-queue wait
time reported by delay statistics. The anomaly was due to the following
reason. When a process leaves the CPU and immediately starts waiting for
CPU on the runqueue (which means it remains in the TASK_RUNNABLE state),
the time of re-entry into the run-queue is never recorded. Due to this,
the waiting time on the runqueue from this point of re-entry upto the
next time it hits the CPU is not accounted for. This is solved by
recording the time of re-entry of a process leaving the CPU in the
sched_info_depart() function IF the process will go back to waiting on
the run-queue. This IF condition is verified by checking whether the
process is still in the TASK_RUNNABLE state.

The patch was tested on 2.6.26-rc6 using two simple CPU hog programs.
The values noted prior to the fix did not account for the time spent on
the runqueue waiting. After the fix, the correct values were reported
back to user space.

Signed-off-by: Bharath Ravi <bharathravi1@gmail.com>
Signed-off-by: Madhava K R  <madhavakr@gmail.com>
Cc: dhaval@linux.vnet.ibm.com
Cc: vatsa@in.ibm.com
Cc: balbir@in.ibm.com
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-19 14:15:28 +02:00
Linus Torvalds
1a750e0cd7 x86, bitops: make constant-bit set/clear_bit ops faster
On Wed, 18 Jun 2008, Linus Torvalds wrote:
>
> And yes, the "lock andl" should be noticeably faster than the xchgl.

I dunno. Here's a untested (!!) patch that turns constant-bit
set/clear_bit ops into byte mask ops (lock orb/andb).

It's not exactly pretty. The reason for using the byte versions is that a
locked op is serialized in the memory pipeline anyway, so there are no
forwarding issues (that could slow down things when we access things with
different sizes), and the byte ops are a lot smaller than 32-bit and
particularly 64-bit ops (big constants, and the 64-bit ops need the REX
prefix byte too).

[ Side note: I wonder if we should turn the "test_bit()" C version into a
  "char *" version too.. It could actually help with alias analysis, since
  char pointers can alias anything. So it might be the RightThing(tm) to
  do for multiple reasons. I dunno. It's a separate issue. ]

It does actually shrink the kernel image a bit (a couple of hundred bytes
on the text segment for my everything-compiled-in image), and while it's
totally untested the (admittedly few) code generation points I looked at
seemed sane. And "lock orb" should be noticeably faster than "lock bts".

If somebody wants to play with it, go wild. I didn't do "change_bit()",
because nobody sane uses that thing anyway. I guarantee nothing. And if it
breaks, nobody saw me do anything.  You can't prove this email wasn't sent
by somebody who is good at forging smtp.

This does require a gcc that is recent enough for "__builtin_constant_p()"
to work in an inline function, but I suspect our kernel requirements are
already higher than that. And if you do have an old gcc that is supported,
the worst that would happen is that the optimization doesn't trigger.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-19 13:45:51 +02:00
Ingo Molnar
7aa413def7 x86, MM: virtual address debug, cleanups
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-19 13:33:11 +02:00