Aneesh Kumar K.V aefa5688c0 powerpc/mm: don't do tlbie for updatepp request with NO HPTE fault ... upatepp can get called for a nohpte fault when we find from the linux page table that the translation was hashed before. In that case we are sure that there is no existing translation, hence we could avoid doing tlbie. We could possibly race with a parallel fault filling the TLB. But that should be ok because updatepp is only ever relaxing permissions. We also look at linux pte permission bits when filling hash pte permission bits. We also hold the linux pte busy bits while inserting/updating a hashpte entry, hence a paralle update of linux pte is not possible. On the other hand mprotect involves ptep_modify_prot_start which cause a hpte invalidate and not updatepp. Performance number: We use randbox_access_bench written by Anton. Kernel with THP disabled and smaller hash page table size. 86.60% random_access_b [kernel.kallsyms] [k] .native_hpte_updatepp 2.10% random_access_b random_access_bench [.] doit 1.99% random_access_b [kernel.kallsyms] [k] .do_raw_spin_lock 1.85% random_access_b [kernel.kallsyms] [k] .native_hpte_insert 1.26% random_access_b [kernel.kallsyms] [k] .native_flush_hash_range 1.18% random_access_b [kernel.kallsyms] [k] .__delay 0.69% random_access_b [kernel.kallsyms] [k] .native_hpte_remove 0.37% random_access_b [kernel.kallsyms] [k] .clear_user_page 0.34% random_access_b [kernel.kallsyms] [k] .__hash_page_64K 0.32% random_access_b [kernel.kallsyms] [k] fast_exception_return 0.30% random_access_b [kernel.kallsyms] [k] .hash_page_mm With Fix: 27.54% random_access_b random_access_bench [.] doit 22.90% random_access_b [kernel.kallsyms] [k] .native_hpte_insert 5.76% random_access_b [kernel.kallsyms] [k] .native_hpte_remove 5.20% random_access_b [kernel.kallsyms] [k] fast_exception_return 5.12% random_access_b [kernel.kallsyms] [k] .__hash_page_64K 4.80% random_access_b [kernel.kallsyms] [k] .hash_page_mm 3.31% random_access_b [kernel.kallsyms] [k] data_access_common 1.84% random_access_b [kernel.kallsyms] [k] .trace_hardirqs_on_caller Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>		2014-12-05 16:26:15 +11:00
..
base.c
context.c
cxl.h	cxl: Name interrupts in /proc/interrupt	2014-11-18 13:01:39 +11:00
debugfs.c
fault.c	powerpc/mm: don't do tlbie for updatepp request with NO HPTE fault	2014-12-05 16:26:15 +11:00
file.c	cxl: Fix afu_read() not doing finish_wait() on signal or non-blocking	2014-10-09 11:29:57 +11:00
irq.c	cxl: Name interrupts in /proc/interrupt	2014-11-18 13:01:39 +11:00
Kconfig	cxl: Add driver to Kbuild and Makefiles	2014-10-08 20:15:58 +11:00
main.c
Makefile	cxl: Add driver to Kbuild and Makefiles	2014-10-08 20:15:58 +11:00
native.c	cxl: Return error to PSL if IRQ demultiplexing fails & print clearer warning	2014-11-18 12:58:38 +11:00
pci.c
sysfs.c