On Mon, Aug 15, 2016 at 02:45:46PM +0800, Jisheng Zhang wrote: > These objects are set during initialization, thereafter are read only. > > Previously I only want to mark vdso_pages, vdso_spec, vectors_page and > cpu_ops as __read_mostly from performance point of view. Then inspired > by Kees's patch[1] to apply more __ro_after_init for arm, I think it's > better to mark them as __ro_after_init. What's more, I find some more > objects are also read only after init. So apply __ro_after_init to all > of them. > > This patch also removes global vdso_pagelist and tries to clean up > vdso_spec[] assignment code. > > [1] http://www.spinics.net/lists/arm-kernel/msg523188.html > > Signed-off-by: Jisheng Zhang <[email protected]>
This looks good to me. With or without the include cleanup in vdso.c: Acked-by: Mark Rutland <[email protected]> Mark. > --- > arch/arm64/kernel/cpu_ops.c | 3 ++- > arch/arm64/kernel/kaslr.c | 3 ++- > arch/arm64/kernel/vdso.c | 30 +++++++++++++++--------------- > arch/arm64/mm/dma-mapping.c | 3 ++- > arch/arm64/mm/init.c | 5 +++-- > arch/arm64/mm/mmu.c | 3 ++- > 6 files changed, 26 insertions(+), 21 deletions(-) > > diff --git a/arch/arm64/kernel/cpu_ops.c b/arch/arm64/kernel/cpu_ops.c > index c7cfb8f..e137cea 100644 > --- a/arch/arm64/kernel/cpu_ops.c > +++ b/arch/arm64/kernel/cpu_ops.c > @@ -17,6 +17,7 @@ > */ > > #include <linux/acpi.h> > +#include <linux/cache.h> > #include <linux/errno.h> > #include <linux/of.h> > #include <linux/string.h> > @@ -28,7 +29,7 @@ extern const struct cpu_operations smp_spin_table_ops; > extern const struct cpu_operations acpi_parking_protocol_ops; > extern const struct cpu_operations cpu_psci_ops; > > -const struct cpu_operations *cpu_ops[NR_CPUS]; > +const struct cpu_operations *cpu_ops[NR_CPUS] __ro_after_init; > > static const struct cpu_operations *dt_supported_cpu_ops[] __initconst = { > &smp_spin_table_ops, > diff --git a/arch/arm64/kernel/kaslr.c b/arch/arm64/kernel/kaslr.c > index b054691..769f24e 100644 > --- a/arch/arm64/kernel/kaslr.c > +++ b/arch/arm64/kernel/kaslr.c > @@ -6,6 +6,7 @@ > * published by the Free Software Foundation. > */ > > +#include <linux/cache.h> > #include <linux/crc32.h> > #include <linux/init.h> > #include <linux/libfdt.h> > @@ -20,7 +21,7 @@ > #include <asm/pgtable.h> > #include <asm/sections.h> > > -u64 __read_mostly module_alloc_base; > +u64 __ro_after_init module_alloc_base; > u16 __initdata memstart_offset_seed; > > static __init u64 get_kaslr_seed(void *fdt) > diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c > index 10ad8ab..6225612 100644 > --- a/arch/arm64/kernel/vdso.c > +++ b/arch/arm64/kernel/vdso.c > @@ -18,12 +18,13 @@ > * Author: Will Deacon <[email protected]> > */ > > -#include <linux/kernel.h> > +#include <linux/cache.h> > #include <linux/clocksource.h> > #include <linux/elf.h> > #include <linux/err.h> > #include <linux/errno.h> > #include <linux/gfp.h> > +#include <linux/kernel.h> > #include <linux/mm.h> > #include <linux/sched.h> > #include <linux/signal.h> > @@ -37,8 +38,7 @@ > #include <asm/vdso_datapage.h> > > extern char vdso_start, vdso_end; > -static unsigned long vdso_pages; > -static struct page **vdso_pagelist; > +static unsigned long vdso_pages __ro_after_init; > > /* > * The vDSO data page. > @@ -53,7 +53,7 @@ struct vdso_data *vdso_data = &vdso_data_store.data; > /* > * Create and map the vectors page for AArch32 tasks. > */ > -static struct page *vectors_page[1]; > +static struct page *vectors_page[1] __ro_after_init; > > static int __init alloc_vectors_page(void) > { > @@ -110,11 +110,19 @@ int aarch32_setup_vectors_page(struct linux_binprm > *bprm, int uses_interp) > } > #endif /* CONFIG_COMPAT */ > > -static struct vm_special_mapping vdso_spec[2]; > +static struct vm_special_mapping vdso_spec[2] __ro_after_init = { > + { > + .name = "[vvar]", > + }, > + { > + .name = "[vdso]", > + }, > +}; > > static int __init vdso_init(void) > { > int i; > + struct page **vdso_pagelist; > > if (memcmp(&vdso_start, "\177ELF", 4)) { > pr_err("vDSO is not a valid ELF object!\n"); > @@ -138,16 +146,8 @@ static int __init vdso_init(void) > for (i = 0; i < vdso_pages; i++) > vdso_pagelist[i + 1] = pfn_to_page(PHYS_PFN(__pa(&vdso_start)) > + i); > > - /* Populate the special mapping structures */ > - vdso_spec[0] = (struct vm_special_mapping) { > - .name = "[vvar]", > - .pages = vdso_pagelist, > - }; > - > - vdso_spec[1] = (struct vm_special_mapping) { > - .name = "[vdso]", > - .pages = &vdso_pagelist[1], > - }; > + vdso_spec[0].pages = &vdso_pagelist[0]; > + vdso_spec[1].pages = &vdso_pagelist[1]; > > return 0; > } > diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c > index c4284c4..5cd202f 100644 > --- a/arch/arm64/mm/dma-mapping.c > +++ b/arch/arm64/mm/dma-mapping.c > @@ -20,6 +20,7 @@ > #include <linux/gfp.h> > #include <linux/acpi.h> > #include <linux/bootmem.h> > +#include <linux/cache.h> > #include <linux/export.h> > #include <linux/slab.h> > #include <linux/genalloc.h> > @@ -30,7 +31,7 @@ > > #include <asm/cacheflush.h> > > -static int swiotlb __read_mostly; > +static int swiotlb __ro_after_init; > > static pgprot_t __get_dma_pgprot(unsigned long attrs, pgprot_t prot, > bool coherent) > diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c > index bbb7ee7..251e082 100644 > --- a/arch/arm64/mm/init.c > +++ b/arch/arm64/mm/init.c > @@ -23,6 +23,7 @@ > #include <linux/swap.h> > #include <linux/init.h> > #include <linux/bootmem.h> > +#include <linux/cache.h> > #include <linux/mman.h> > #include <linux/nodemask.h> > #include <linux/initrd.h> > @@ -55,8 +56,8 @@ > * executes, which assigns it its actual value. So use a default value > * that cannot be mistaken for a real physical address. > */ > -s64 memstart_addr __read_mostly = -1; > -phys_addr_t arm64_dma_phys_limit __read_mostly; > +s64 memstart_addr __ro_after_init = -1; > +phys_addr_t arm64_dma_phys_limit __ro_after_init; > > #ifdef CONFIG_BLK_DEV_INITRD > static int __init early_initrd(char *p) > diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c > index 4989948..e634a0f 100644 > --- a/arch/arm64/mm/mmu.c > +++ b/arch/arm64/mm/mmu.c > @@ -17,6 +17,7 @@ > * along with this program. If not, see <http://www.gnu.org/licenses/>. > */ > > +#include <linux/cache.h> > #include <linux/export.h> > #include <linux/kernel.h> > #include <linux/errno.h> > @@ -46,7 +47,7 @@ > > u64 idmap_t0sz = TCR_T0SZ(VA_BITS); > > -u64 kimage_voffset __read_mostly; > +u64 kimage_voffset __ro_after_init; > EXPORT_SYMBOL(kimage_voffset); > > /* > -- > 2.8.1 >
