linux/arch/x86/xen
David Vrabel 7eb7ce4d2e xen: correctly check for pending events when restoring irq flags
In xen_restore_fl_direct(), xen_force_evtchn_callback() was being
called even if no events were pending.  This resulted in (depending on
workload) about a 100 times as many xen_version hypercalls as
necessary.

Fix this by correcting the sense of the conditional jump.

This seems to give a significant performance benefit for some
workloads.

There is some subtle tricksy "..since the check here is trying to
check both pending and masked in a single cmpw, but I think this is
correct. It will call check_events now only when the combined
mask+pending word is 0x0001 (aka unmasked, pending)." (Ian)

CC: stable@kernel.org
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-04-27 16:04:21 -04:00
..
debugfs.c switch debugfs to umode_t 2012-01-03 22:54:56 -05:00
debugfs.h switch debugfs to umode_t 2012-01-03 22:54:56 -05:00
enlighten.c xen/enlighten: Disable MWAIT_LEAF so that acpi-pad won't be loaded. 2012-04-26 17:46:20 -04:00
grant-table.c Merge commit 'v3.2-rc3' into stable/for-linus-3.3 2011-12-20 17:01:18 -05:00
irq.c xen: use this_cpu_xxx replace percpu_xxx funcs 2012-01-24 12:20:24 -05:00
Kconfig xen: Make XEN_MAX_DOMAIN_MEMORY have more sensible defaults 2011-11-21 17:14:46 -05:00
Makefile xen/tracing: Fix tracing config option properly 2011-08-22 11:28:33 -04:00
mmu.c Two fixes for regressions: 2012-04-06 17:54:53 -07:00
mmu.h xen: make a pile of mmu pvop functions static 2011-05-20 14:25:24 -07:00
multicalls.c xen/multicall: move *idx fields to start of mc_buffer 2011-07-18 15:43:46 -07:00
multicalls.h xen: use this_cpu_xxx replace percpu_xxx funcs 2012-01-24 12:20:24 -05:00
p2m.c Revert "xen/p2m: m2p_find_override: use list_for_each_entry_safe" 2012-04-20 11:56:00 -04:00
pci-swiotlb-xen.c X86 & IA64: adapt for dma_map_ops changes 2012-03-28 16:36:31 +02:00
platform-pci-unplug.c xen:pvhvm: Modpost section mismatch fix 2011-07-11 13:37:04 -04:00
setup.c xen/cpufreq: Disable the cpu frequency scaling drivers from loading. 2012-03-20 15:31:38 -04:00
smp.c xen/smp: Fix crash when booting with ACPI hotplug CPUs. 2012-04-26 22:07:21 -04:00
spinlock.c x86: xen: size struct xen_spinlock to always fit in arch_spinlock_t 2012-01-24 12:10:19 -05:00
suspend.c xen: suspend: add "arch" to pre/post suspend hooks 2011-02-25 16:43:12 +00:00
time.c Merge branch 'upstream/xen-settime' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen 2011-11-06 20:15:05 -08:00
trace.c xen/trace: Fix compile error when CONFIG_XEN_PRIVILEGED_GUEST is not set 2011-08-05 09:43:02 -04:00
vdso.h
vga.c xen: allow enable use of VGA console on dom0 2011-06-06 11:46:00 -04:00
xen-asm_32.S xen: x86_32: do not enable iterrupts when returning from exception in interrupt context 2011-09-01 12:54:42 -04:00
xen-asm_64.S xen: use iret for return from 64b kernel to 32b usermode 2009-12-03 11:14:54 -08:00
xen-asm.h
xen-asm.S xen: correctly check for pending events when restoring irq flags 2012-04-27 16:04:21 -04:00
xen-head.S x86, asm: Cleanup unnecssary macros in asm-offsets.c 2011-02-25 16:37:32 -08:00
xen-ops.h Merge branch 'stable/vga.support' into stable/drivers 2011-06-21 09:25:41 -04:00