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  1. 18 Jan, 2010 2 commits
    • Suresh Siddha's avatar
      x86, irq: Use 0x20 for the IRQ_MOVE_CLEANUP_VECTOR instead of 0x1f · 6579b474
      Suresh Siddha authored 
      After talking to some more folks inside intel (Peter Anvin, Asit Mallick),
the safest option (for future compatibility etc) seen was to use vector 0x20
for IRQ_MOVE_CLEANUP_VECTOR instead of using vector 0x1f (which is documented as
reserved vector in the Intel IA32 manuals).

Also we don't need to reserve the entire privilege level (all 16 vectors in
the priority bucket that IRQ_MOVE_CLEANUP_VECTOR falls into), as the
x86 architecture (section 10.9.3 in SDM Vol3a) specifies that with in the
priority level, the higher the vector number the higher the priority.
And hence we don't need to reserve the complete priority level 0x20-0x2f for
the IRQ migration cleanup logic.

So change the IRQ_MOVE_CLEANUP_VECTOR to 0x20 and  allow 0x21-0x2f to be used
for device interrupts. 0x30-0x3f will be used for ISA interrupts (these
also can be migrated in the context of IOAPIC and hence need to be at a higher
priority level than IRQ_MOVE_CLEANUP_VECTOR).
Signed-off-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <20100114002118.521826763@sbs-t61.sc.intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
      6579b474
    • Suresh Siddha's avatar
      x86, vmi: Fix vmi_get_timer_vector() to use IRQ0_VECTOR · 722b3654
      Suresh Siddha authored 
      FIRST_DEVICE_VECTOR is going away and it looks like a bad hack to steal
FIRST_DEVICE_VECTOR / FIRST_EXTERNAL_VECTOR, when it looks like it needs
IRQ0_VECTOR.

Fix vmi_get_timer_vector() to use IRQ0_VECTOR.
Signed-off-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <20100114002118.436172066@sbs-t61.sc.intel.com>
Cc: Alok N Kataria <akataria@vmware.com>
Cc: Zach Amsden <zach@vmware.com>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
      722b3654
  3. 05 Jan, 2010 2 commits
    • H. Peter Anvin's avatar
      x86, apic: Don't waste a vector to improve vector spread · ea943966
      H. Peter Anvin authored 
      We want to use a vector-assignment sequence that avoids stumbling onto
0x80 earlier in the sequence, in order to improve the spread of
vectors across priority levels on machines with a small number of
interrupt sources.  Right now, this is done by simply making the first
vector (0x31 or 0x41) completely unusable.  This is unnecessary; all
we need is to start assignment at a +1 offset, we don't actually need
to prohibit the usage of this vector once we have wrapped around.
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
LKML-Reference: <4B426550.6000209@kernel.org>
      ea943966
    • H. Peter Anvin's avatar
      x86, apic: Reclaim IDT vectors 0x20-0x2f · 99d113b1
      H. Peter Anvin authored 
      Reclaim 16 IDT vectors and make them available for general allocation.

Reclaim vectors 0x20-0x2f by reallocating the IRQ_MOVE_CLEANUP_VECTOR
to vector 0x1f.  This is in the range of vector numbers that is
officially reserved for the CPU (for exceptions), however, the use of
the APIC to generate any vector 0x10 or above is documented, and the
CPU internally can receive any vector number (the legacy BIOS uses INT
0x08-0x0f for interrupts, as messed up as that is.)

Since IRQ_MOVE_CLEANUP_VECTOR has to be alone in the lowest-numbered
priority level (block of 16), this effectively enables us to reclaim
an otherwise-unusable APIC priority level and put it to use.

Since this is a transient kernel-only allocation we can change it at
any time, and if/when there is an exception at vector 0x1f this
assignment needs to be changed as part of OS enabling that new feature.
Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
LKML-Reference: <4B4284C6.9030107@kernel.org>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
      99d113b1
  5. 30 Dec, 2009 1 commit
    • Yinghai Lu's avatar
      x86: Increase NR_IRQS and nr_irqs · 9959c888
      Yinghai Lu authored 
      I have a system with lots of igb and ixgbe, when iov/vf are
enabled for them, we hit the limit of 3064.

when system has 20 pcie installed, and one card has 2
functions, and one function needs 64 msi-x,
 may need 20 * 2 * 64 = 2560 for msi-x

but if iov and vf are enabled
 may need 20 * 2 * 64 * 3 = 7680 for msi-x
assume system with 5 ioapic, nr_irqs_gsi will be 120.

NR_CPUS = 512, and nr_cpu_ids = 128
will have NR_IRQS = 256 + 512 * 64 = 33024
will have nr_irqs = 120 + 8 * 128 + 120 * 64 = 8824

When SPARSE_IRQ is not set, there is no increase with kernel data
size.

when NR_CPUS=128, and SPARSE_IRQ is set:
   text		   data	    bss		   dec		 hex	filename
21837444	4216564	12480736	38534744	24bfe58	vmlinux.before
21837442	4216580	12480736	38534758	24bfe66	vmlinux.after
when NR_CPUS=4096, and SPARSE_IRQ is set
   text		   data	    bss		   dec		 hex	filename
21878619	5610244	13415392	40904255	270263f	vmlinux.before
21878617	5610244	13415392	40904253	270263d	vmlinux.after
Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <4B398ECD.1080506@kernel.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      9959c888
  7. 24 Dec, 2009 35 commits
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