task_tick_rt() has an optimization to only reschedule SCHED_RR tasks
if they were the only element on their rq. However, with cgroups
a SCHED_RR task could be the only element on its per-cgroup rq but
still be competing with other SCHED_RR tasks in its parent's
cgroup. In this case, the SCHED_RR task in the child cgroup would
never yield at the end of its timeslice. If the child cgroup
rt_runtime_us was the same as the parent cgroup rt_runtime_us,
the task in the parent cgroup would starve completely.
Modify task_tick_rt() to check that the task is the only task on its
rq, and that the each of the scheduling entities of its ancestors
is also the only entity on its rq.
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1337229266-15798-1-git-send-email-ccross@android.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
SD_OVERLAP exists to allow overlapping groups, overlapping groups
appear in NUMA topologies that aren't fully connected.
The typical result of not fully connected NUMA is that each cpu (or
rather node) will have different spans for a particular distance.
However due to how sched domains are traversed -- only the first cpu
in the mask goes one level up -- the next level only cares about the
spans of the cpus that went up.
Due to this two things were observed to be broken:
- build_overlap_sched_groups() -- since its possible the cpu we're
building the groups for exists in multiple (or all) groups, the
selection criteria of the first group didn't ensure there was a cpu
for which is was true that cpumask_first(span) == cpu. Thus load-
balancing would terminate.
- update_group_power() -- assumed that the cpu span of the first
group of the domain was covered by all groups of the child domain.
The above explains why this isn't true, so deal with it.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: David Rientjes <rientjes@google.com>
Link: http://lkml.kernel.org/r/1337788843.9783.14.camel@laptop
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Follow up on commit 556061b00 ("sched/nohz: Fix rq->cpu_load[]
calculations") since while that fixed the busy case it regressed the
mostly idle case.
Add a callback from the nohz exit to also age the rq->cpu_load[]
array. This closes the hole where either there was no nohz load
balance pass during the nohz, or there was a 'significant' amount of
idle time between the last nohz balance and the nohz exit.
So we'll update unconditionally from the tick to not insert any
accidental 0 load periods while busy, and we try and catch up from
nohz idle balance and nohz exit. Both these are still prone to missing
a jiffy, but that has always been the case.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: pjt@google.com
Cc: Venkatesh Pallipadi <venki@google.com>
Link: http://lkml.kernel.org/n/tip-kt0trz0apodbf84ucjfdbr1a@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit c751085943
Author: Rafael J. Wysocki <rjw@sisk.pl>
Date: Sun Apr 12 20:06:56 2009 +0200
PM/Hibernate: Wait for SCSI devices scan to complete during resume
Broke the scsi_wait_scan module in 2.6.30. Apparently debian still uses it so
fix it and backport to stable before removing it in 3.6.
The breakage is caused because the function template in
include/scsi/scsi_scan.h is defined to be a nop unless SCSI is built in.
That means that in the modular case (which is every distro), the
scsi_wait_scan module does a simple async_synchronize_full() instead of
waiting for scans.
Cc: <stable@vger.kernel.org>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Commit a7a20d1 "[SCSI] sd: limit the scope of the async probe domain"
moved sd probe work out of reach of wait_for_device_probe(). Allow it
to be synced via scsi_complete_async_scans().
Reported-by: Meelis Roos <mroos@linux.ee>
Tested-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
This patch should go into 3.5 fixes. The bug was added in the
patches for the 3.5 feature window.
As you can see from the patch I made a mistake. During
development I switched from passing a struct to the size of
the struct, but left the sizeof. This results in us allocating
4 bytes (sizeof(int)) but then calling pci_free_consistent
with the size of the struct.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
change_queue_depth will adjust device queuedepth upon receiving
"SAM_STAT_TASK_SET_FULL" scsi status from the target.
Also added ql4xqfulltracking command line param to enable or disable
queuefull tracking. One can disabling queuefull tracking to ensure
user set scsi device queuedepth is not altered.
Signed-off-by: Tej Parkash <tej.parkash@qlogic.com>
Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Merge back Linus's latest branch so that we pick up the uprobes changes.
( I tested this branch locally and while it's one from the middle of the
merge window it's a good one to base further work off. )
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Allow ddb state to change to DDB_DS_NO_CONNECTION_ACTIVE or
DDB_DS_SESSION_FAILED before issuing clear ddb mailbox cmd,
because clear ddb mailbox cmd fails if the ddb state is not
equal to DDB_DS_NO_CONNECTION_ACTIVE or DDB_DS_SESSION_FAILED.
Signed-off-by: Manish Rangankar <manish.rangankar@qlogic.com>
Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Function pat_pagerange_is_ram() scales poorly to large address
ranges, because it probes the resource tree for each page.
On a 2.6 GHz Opteron, this function consumes 34 ms for a 1 GB range.
It is called twice during untrack_pfn_vma(), slowing process
cleanup and handicapping the OOM killer.
This replacement consumes less than 1ms, under the same conditions.
Signed-off-by: John Dykstra <jdykstra@cray.com> on behalf of Cray Inc.
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1337980366.1979.6.camel@redwood
[ Small stylistic cleanups and renames ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Update the session and connection parameter before sending
connection logged in event to iscsiadm because in some
scenario logout may come in just after we send the logged
in event to user, which free up session, connection and ddb,
but DPC is still updating session and connect parameter
which can lead to panic.
Signed-off-by: Manish Rangankar <manish.rangankar@qlogic.com>
Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Since there are uses for I2C_M_NOSTART which are much more sensible and
standard than most of the protocol mangling functionality (the main one
being gather writes to devices where something like a register address
needs to be inserted before a block of data) create a new I2C_FUNC_NOSTART
for this feature and update all the users to use it.
Also strengthen the disrecommendation of the protocol mangling while we're
at it.
In the case of regmap-i2c we remove the requirement for mangling as
I2C_M_NOSTART is the only mangling feature which is being used.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
