kernel-hacking-2024-linux-s.../arch/x86
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
..
boot
configs
crypto crypto: x86/sha512_ssse3 - fixup for asm function prototype change 2015-04-24 20:09:01 +08:00
ia32 x86_64, asm: Work around AMD SYSRET SS descriptor attribute issue 2015-04-26 17:57:38 -07:00
include x86: pvclock: Really remove the sched notifier for cross-cpu migrations 2015-04-27 15:49:30 +02:00
kernel x86: pvclock: Really remove the sched notifier for cross-cpu migrations 2015-04-27 15:49:30 +02:00
kvm kvm: x86: fix kvmclock update protocol 2015-04-27 15:48:59 +02:00
lguest Some virtio internal cleanups, a new virtio device "virtio input", and 2015-04-22 10:55:06 -07:00
lib x86: fix special __probe_kernel_write() tail zeroing case 2015-04-24 06:58:27 -07:00
math-emu
mm mm: move memtest under mm 2015-04-14 16:49:06 -07:00
net
oprofile
pci PCI changes for the v4.1 merge window: 2015-04-13 15:45:47 -07:00
platform TTY/Serial patches for 4.1-rc1 2015-04-21 09:33:10 -07:00
power
purgatory
realmode
syscalls xen: features and fixes for 4.1-rc0 2015-04-16 14:01:03 -05:00
tools
um Merge branch 'exec_domain_rip_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2015-04-15 13:53:55 -07:00
vdso x86: pvclock: Really remove the sched notifier for cross-cpu migrations 2015-04-27 15:49:30 +02:00
video
xen xen: features and fixes for 4.1-rc0 2015-04-16 14:01:03 -05:00
.gitignore
Kbuild
Kconfig Initial ACPI support for arm64: 2015-04-24 08:23:45 -07:00
Kconfig.cpu
Kconfig.debug
Makefile
Makefile.um
Makefile_32.cpu