Re: X15 alpha release: as fast as TUX but in user space (fwd)

[Andrea Arcangeli]

On Sun, Apr 29, 2001 at 09:38:04PM +0200, Jamie Lokier wrote:
> Fwiw, modern x86 has global TLB entries too.

my x86-64 implementation is marking the tlb entry global of course (so
it's not flushed during context switch):

#define __PAGE_KERNEL_VSYSCALL \
	(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
#define MAKE_GLOBAL(x) __pgprot((x) | _PAGE_GLOBAL)
#define PAGE_KERNEL_VSYSCALL MAKE_GLOBAL(__PAGE_KERNEL_VSYSCALL)

static void __init map_vsyscall(void)
{
	extern char __vsyscall_0;
	unsigned long physaddr_page0 = (unsigned long) &__vsyscall_0 - __START_KERNEL_map;

	__set_fixmap(VSYSCALL_FIRST_PAGE, physaddr_page0, PAGE_KERNEL_VSYSCALL);
}

Andrea