The problem we can't take advantage of lowest priority delivery mode if
the vectors are allocated for only one cpu at a time. Nor can we work
around hardware that assumes lowest priority delivery mode is always
used with several cpus.
So this patch introduces the concept of a vector_allocation_domain. A
set of cpus that will receive an irq on the same vector. Currently the
code for implementing this is placed in the genapic structure so we can
vary this depending on how we are using the io_apics.
This allows us to restore the previous behaviour of genapic_flat without
removing the benefits of having separate vector allocation for large
machines.
This should also fix the problem report where a hyperthreaded cpu was
receving the irq on the wrong hyperthread when in logical delivery mode
because the previous behaviour is restored.
This patch properly records our allocation of the first 16 irqs to the
first 16 available vectors on all cpus. This should be fine but it may
run into problems with multiple interrupts at the same interrupt level.
Except for some badly maintained comments in the code and the behaviour
of the interrupt allocator I have no real understanding of that problem.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Muli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The genapic field and the accessor macro weren't used anywhere.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
I noticed that some lowlevel send_IPI_mask helpers had a hotplug/preempt
race whereupon the cpu_online_map was read before disabling preemption;
...
cpumask_t mask = cpu_online_map;
int cpu = get_cpu();
cpu_clear(cpu, mask);
...
But then i realised that there is no need for these lowlevel functions to
be going through all this trouble when all the callers are already made
hotplug/preempt safe.
Signed-off-by: Zwane Mwaikambo <zwane@arm.linux.org.uk>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
No x86-64 chipset has this bug
Generated code doesn't change because it was always disabled.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Need to ensure we dont get prempted when we clear ourself from mask when using
clustered mode genapic code.
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Acked-by: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Eric W. Biederman