From 1aea9b3f921003f0880f0676ae85d87c9f1cb4a2 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Mon, 24 Apr 2017 18:19:10 +0200 Subject: s390/mm: implement 5 level pages tables Add the logic to upgrade the page table for a 64-bit process to five levels. This increases the TASK_SIZE from 8PB to 16EB-4K. Signed-off-by: Martin Schwidefsky --- arch/s390/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/s390/Kconfig') diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index e161faf..e7ff581 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -184,7 +184,7 @@ config SCHED_OMIT_FRAME_POINTER config PGTABLE_LEVELS int - default 4 + default 5 source "init/Kconfig" -- cgit v1.1 From 23fefe119ceb5fb0c7d3321010620010a4eddb18 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Wed, 7 Jun 2017 14:10:24 +0200 Subject: s390/kvm: avoid global config of vm.alloc_pgste=1 The system control vm.alloc_pgste is used to control the size of the page tables, either 2K or 4K. The idea is that a KVM host sets the vm.alloc_pgste control to 1 which causes *all* new processes to run with 4K page tables. For a non-kvm system the control should stay off to save on memory used for page tables. Trouble is that distributions choose to set the control globally to be able to run KVM guests. This wastes memory on non-KVM systems. Introduce the PT_S390_PGSTE ELF segment type to "mark" the qemu executable with it. All executables with this (empty) segment in its ELF phdr array will be started with 4K page tables. Any executable without PT_S390_PGSTE will run with the default 2K page tables. This removes the need to set vm.alloc_pgste=1 for a KVM host and minimizes the waste of memory for page tables. Signed-off-by: Martin Schwidefsky --- arch/s390/Kconfig | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/s390/Kconfig') diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index e7ff581..bb11f9f 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -64,6 +64,7 @@ config ARCH_SUPPORTS_UPROBES config S390 def_bool y + select ARCH_BINFMT_ELF_STATE select ARCH_HAS_DEVMEM_IS_ALLOWED select ARCH_HAS_ELF_RANDOMIZE select ARCH_HAS_GCOV_PROFILE_ALL -- cgit v1.1 From e1073d1e7920946ac4776a619cc40668b9e1401b Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Thu, 6 Jul 2017 15:39:17 -0700 Subject: mm/hugetlb: clean up ARCH_HAS_GIGANTIC_PAGE This moves the #ifdef in C code to a Kconfig dependency. Also we move the gigantic_page_supported() function to be arch specific. This allows architectures to conditionally enable runtime allocation of gigantic huge page. Architectures like ppc64 supports different gigantic huge page size (16G and 1G) based on the translation mode selected. This provides an opportunity for ppc64 to enable runtime allocation only w.r.t 1G hugepage. No functional change in this patch. Link: http://lkml.kernel.org/r/1494995292-4443-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com Signed-off-by: Aneesh Kumar K.V Cc: Michael Ellerman (powerpc) Cc: Anshuman Khandual Cc: Benjamin Herrenschmidt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/s390/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/s390/Kconfig') diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 37abe86..7eeb75d 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -68,7 +68,7 @@ config S390 select ARCH_HAS_DEVMEM_IS_ALLOWED select ARCH_HAS_ELF_RANDOMIZE select ARCH_HAS_GCOV_PROFILE_ALL - select ARCH_HAS_GIGANTIC_PAGE + select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA select ARCH_HAS_KCOV select ARCH_HAS_SET_MEMORY select ARCH_HAS_SG_CHAIN -- cgit v1.1