linux/arch/x86/vdso
Paolo Bonzini 73459e2a1a x86: pvclock: Really remove the sched notifier for cross-cpu migrations
This reverts commits 0a4e6be9ca
and 80f7fdb1c7.

The task migration notifier was originally introduced in order to support
the pvclock vsyscall with non-synchronized TSC, but KVM only supports it
with synchronized TSC.  Hence, on KVM the race condition is only needed
due to a bad implementation on the host side, and even then it's so rare
that it's mostly theoretical.

As far as KVM is concerned it's possible to fix the host, avoiding the
additional complexity in the vDSO and the (re)introduction of the task
migration notifier.

Xen, on the other hand, hasn't yet implemented vsyscall support at
all, so we do not care about its plans for non-synchronized TSC.

Reported-by: Peter Zijlstra <peterz@infradead.org>
Suggested-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-04-27 15:49:30 +02:00
..
vdso32 x86/vdso32/syscall.S: Do not load __USER32_DS to %ss 2015-03-31 10:45:15 +02:00
.gitignore x86, vdso: Reimplement vdso.so preparation in build-time C 2014-05-05 13:18:51 -07:00
checkundef.sh x86, vdso: Don't quote $nm in the script for checking vdso references 2010-07-27 23:52:29 -07:00
Makefile x86/vdso: Remove x32 intermediates during 'make clean' 2015-03-31 10:45:15 +02:00
vclock_gettime.c x86: pvclock: Really remove the sched notifier for cross-cpu migrations 2015-04-27 15:49:30 +02:00
vdso2c.c x86, vdso: Get rid of the fake section mechanism 2014-07-11 16:58:07 -07:00
vdso2c.h x86/vdso: Fix vdso2c's special_pages[] error checking 2014-09-24 09:55:38 +02:00
vdso32-setup.c arm64,ia64,ppc,s390,sh,tile,um,x86,mm: remove default gate area 2014-08-08 15:57:27 -07:00
vdso-layout.lds.S x86, vdso: Move the vvar area before the vdso text 2014-07-11 16:57:51 -07:00
vdso-note.S x86_64: move vdso 2007-10-11 11:17:10 +02:00
vdso.lds.S x86/vdso: Improve the fake section headers 2014-06-19 15:45:12 -07:00
vdsox32.lds.S x86/vdso: Improve the fake section headers 2014-06-19 15:45:12 -07:00
vgetcpu.c x86,vdso: Use LSL unconditionally for vgetcpu 2014-11-03 13:41:53 +01:00
vma.c x86_64, vdso: Fix the vdso address randomization algorithm 2014-12-20 16:56:57 -08:00