linux/arch
Boris Ostrovsky 14520c92cb xen/pci: Use APIC directly when APIC virtualization hardware is available
When hardware supports APIC/x2APIC virtualization we don't need to use
pirqs for MSI handling and instead use APIC since most APIC accesses
(MMIO or MSR) will now be processed without VMEXITs.

As an example, netperf on the original code produces this profile
(collected wih 'xentrace -e 0x0008ffff -T 5'):

    342 cpu_change
    260 CPUID
  34638 HLT
  64067 INJ_VIRQ
  28374 INTR
  82733 INTR_WINDOW
     10 NPF
  24337 TRAP
 370610 vlapic_accept_pic_intr
 307528 VMENTRY
 307527 VMEXIT
 140998 VMMCALL
    127 wrap_buffer

After applying this patch the same test shows

    230 cpu_change
    260 CPUID
  36542 HLT
    174 INJ_VIRQ
  27250 INTR
    222 INTR_WINDOW
     20 NPF
  24999 TRAP
 381812 vlapic_accept_pic_intr
 166480 VMENTRY
 166479 VMEXIT
  77208 VMMCALL
     81 wrap_buffer

ApacheBench results (ab -n 10000 -c 200) improve by about 10%

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-12-04 13:02:43 +00:00
..
alpha Merge git://git.infradead.org/users/eparis/audit 2014-10-19 16:25:56 -07:00
arc The "weak" attribute is commonly used for the default version of a 2014-10-23 15:04:27 -07:00
arm xen/arm: introduce GNTTABOP_cache_flush 2014-12-04 12:41:54 +00:00
arm64 xen/arm/arm64: merge xen/mm32.c into xen/mm.c 2014-12-04 12:41:53 +00:00
avr32 Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma 2014-10-18 18:11:04 -07:00
blackfin Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2014-10-15 07:48:18 +02:00
c6x
cris Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-13 16:23:15 +02:00
frv frv: remove unused declarations of __start___ex_table and __stop___ex_table 2014-10-14 02:18:28 +02:00
hexagon Merge branch 'locking-arch-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-13 15:48:00 +02:00
ia64 kvm: fix kvm_is_mmio_pfn() and rename to kvm_is_reserved_pfn() 2014-11-26 14:40:45 +01:00
m32r Merge branch 'locking-arch-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-13 15:48:00 +02:00
m68k m68k: Wire up bpf 2014-10-27 11:02:19 +01:00
metag Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2014-10-15 07:48:18 +02:00
microblaze microblaze: Wire up bpf syscall 2014-10-27 09:25:34 +01:00
mips MIPS: tlbex: Fix potential HTW race on TLBL/M/S handlers 2014-11-27 17:21:56 +01:00
mn10300 Merge branch 'locking-arch-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-13 15:48:00 +02:00
openrisc Merge git://git.infradead.org/users/eparis/audit 2014-10-19 16:25:56 -07:00
parisc parisc: Avoid using CONFIG_64BIT in userspace exported headers 2014-11-10 22:25:29 +01:00
powerpc Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux 2014-11-27 18:23:41 -08:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2014-11-05 12:13:52 -08:00
score score: use Kbuild logic to include <asm-generic/sections.h> 2014-10-09 22:25:46 -04:00
sh sh: fix sh770x SCIF memory regions 2014-10-29 16:33:15 -07:00
sparc sparc: Add NOP dma_cache_sync() implementation. 2014-11-26 13:36:41 -08:00
tile Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2014-10-15 07:48:18 +02:00
um Merge git://git.infradead.org/users/eparis/audit 2014-10-19 16:25:56 -07:00
unicore32 nosave: consolidate __nosave_{begin,end} in <asm/sections.h> 2014-10-09 22:26:04 -04:00
x86 xen/pci: Use APIC directly when APIC virtualization hardware is available 2014-12-04 13:02:43 +00:00
xtensa Xtensa improvements for 3.18: 2014-10-23 10:30:33 -07:00
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