Re: [PATCH][RFC] swsusp: speed up image restoring on x86-64

From: Pavel Machek
Date: Fri Jan 21 2005 - 05:07:16 EST


Hi!

> > Sure, but I think it's there for a reason.
> >
> > > Anyway, this is likely to clash with hugang's work; I'd prefer this not to be applied.
> >
> > I am aware of that, but you are not going to merge the hugang's patches soon, are you?
> > If necessary, I can change the patch to work with his code (hugang, what do you think?).
> >
> I like this patch, And I change my code with this, Please have a look,
> It pass in qemu X86_64. :)
>
> Full patch still can get from
> http://soulinfo.com/~hugang/swsusp/2005-1-21/
>
> here is only x86_64 part.

Okay, why not, if you are changing it anyway...


> --- 2.6.11-rc1-mm1/arch/x86_64/kernel/suspend_asm.S 2004-12-30 14:56:35.000000000 +0800
> +++ 2.6.11-rc1-mm1-swsusp-x86_64/arch/x86_64/kernel/suspend_asm.S 2005-01-21 10:13:15.000000000 +0800
> @@ -35,6 +35,7 @@ ENTRY(swsusp_arch_suspend)
> call swsusp_save
> ret
>
> + .section .data.nosave
> ENTRY(swsusp_arch_resume)
> /* set up cr3 */
> leaq init_level4_pgt(%rip),%rax

But why does it go into data section?

> @@ -49,43 +50,32 @@ ENTRY(swsusp_arch_resume)
> movq %rcx, %cr3;
> movq %rax, %cr4; # turn PGE back on
>
> - movl nr_copy_pages(%rip), %eax
> - xorl %ecx, %ecx
> - movq $0, %r10
> - testl %eax, %eax
> - jz done
> -.L105:
> - xorl %esi, %esi
> - movq $0, %r11
> - jmp .L104
> - .p2align 4,,7
> -copy_one_page:
> - movq %r10, %rcx
> -.L104:
> - movq pagedir_nosave(%rip), %rdx
> - movq %rcx, %rax
> - salq $5, %rax
> - movq 8(%rdx,%rax), %rcx
> - movq (%rdx,%rax), %rax
> - movzbl (%rsi,%rax), %eax
> - movb %al, (%rsi,%rcx)
> -
> - movq %cr3, %rax; # flush TLB
> - movq %rax, %cr3;
> -
> - movq %r11, %rax
> - incq %rax
> - cmpq $4095, %rax
> - movq %rax, %rsi
> - movq %rax, %r11
> - jbe copy_one_page
> - movq %r10, %rax
> - incq %rax
> - movq %rax, %rcx
> - movq %rax, %r10
> - mov nr_copy_pages(%rip), %eax
> - cmpq %rax, %rcx
> - jb .L105
> + movq pagedir_nosave(%rip), %rax
> + testq %rax, %rax
> + je done
> +
> +copyback_page:
> + movq 24(%rax), %r9
> + xorl %r8d, %r8d
> +

Are you sure %r8 and %r9 are caller-saved? I'd use low registers if I
were you, they look nincer and generate shorter opcodes ;-).

Pavel
--
People were complaining that M$ turns users into beta-testers...
...jr ghea gurz vagb qrirybcref, naq gurl frrz gb yvxr vg gung jnl!
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