Aneesh Kumar K.V 691e95fd73 powerpc/mm/thp: Make page table walk safe against thp split/collapse ... We can disable a THP split or a hugepage collapse by disabling irq. We do send IPI to all the cpus in the early part of split/collapse, and disabling local irq ensure we don't make progress with split/collapse. If the THP is getting split we return NULL from find_linux_pte_or_hugepte(). For all the current callers it should be ok. We need to be careful if we want to use returned pte_t pointer outside the irq disabled region. W.r.t to THP split, the pfn remains the same, but then a hugepage collapse will result in a pfn change. There are few steps we can take to avoid a hugepage collapse.One way is to take page reference inside the irq disable region. Other option is to take mmap_sem so that a parallel collapse will not happen. We can also disable collapse by taking pmd_lock. Another method used by kvm subsystem is to check whether we had a mmu_notifer update in between using mmu_notifier_retry(). Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>		2015-04-17 11:23:39 +10:00
..
req-gen
bhrb.S
callchain.c	powerpc/mm/thp: Make page table walk safe against thp split/collapse	2015-04-17 11:23:39 +10:00
core-book3s.c	powerpc updates for 4.1	2015-04-16 13:53:32 -05:00
core-fsl-emb.c
e500-pmu.c
e6500-pmu.c
hv-24x7-catalog.h
hv-24x7-domains.h
hv-24x7.c	powerpc updates for 4.1	2015-04-16 13:53:32 -05:00
hv-24x7.h	powerpc/perf/hv-24x7: Modify definition of request and result buffers	2015-04-11 20:49:21 +10:00
hv-common.c
hv-common.h
hv-gpci-requests.h
hv-gpci.c
hv-gpci.h
Makefile
mpc7450-pmu.c
power4-pmu.c
power5-pmu.c
power5+-pmu.c
power6-pmu.c
power7-events-list.h
power7-pmu.c
power8-pmu.c
ppc970-pmu.c