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SubjectRe: [PATCH v2 4/6] x86: Add clear_page_nocache
On Mon, Aug 13, 2012 at 07:04:02PM +0200, Borislav Petkov wrote:
> On Mon, Aug 13, 2012 at 02:43:34PM +0300, Kirill A. Shutemov wrote:
> > $ cat test.c
> > #include <stdio.h>
> > #include <sys/mman.h>
> >
> > #define SIZE 1024*1024*1024
> >
> > void clear_page_nocache_sse2(void *page) __attribute__((regparm(1)));
> >
> > int main(int argc, char** argv)
> > {
> > char *p;
> > unsigned long i, j;
> >
> > p = mmap(NULL, SIZE, PROT_WRITE|PROT_READ,
> > MAP_PRIVATE|MAP_ANONYMOUS|MAP_POPULATE, -1, 0);
> > for(j = 0; j < 100; j++) {
> > for(i = 0; i < SIZE; i += 4096) {
> > clear_page_nocache_sse2(p + i);
> > }
> > }
> >
> > return 0;
> > }
> > $ cat clear_page_nocache_unroll32.S
> > .globl clear_page_nocache_sse2
> > .align 4,0x90
> > clear_page_nocache_sse2:
> > .cfi_startproc
> > mov %eax,%edx
> > xorl %eax,%eax
> > movl $4096/32,%ecx
> > .p2align 4
> > .Lloop_sse2:
> > decl %ecx
> > #define PUT(x) movnti %eax,x*4(%edx)
> > PUT(0)
> > PUT(1)
> > PUT(2)
> > PUT(3)
> > PUT(4)
> > PUT(5)
> > PUT(6)
> > PUT(7)
> > #undef PUT
> > lea 32(%edx),%edx
> > jnz .Lloop_sse2
> > nop
> > ret
> > .cfi_endproc
> > .type clear_page_nocache_sse2, @function
> > .size clear_page_nocache_sse2, .-clear_page_nocache_sse2
> > $ cat clear_page_nocache_unroll64.S
> > .globl clear_page_nocache_sse2
> > .align 4,0x90
> > clear_page_nocache_sse2:
> > .cfi_startproc
> > mov %eax,%edx
>
> This must still be the 32-bit version becaue it segfaults here.

Yes, it's test for 32-bit version.

--
Kirill A. Shutemov


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