lkml.org 
[lkml]   [2016]   [Feb]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] arm64: add architecture specified current_pt_regs
On Fri, Feb 19, 2016 at 10:30:09AM +0800, Zhi-zhou wrote:
> On Thu, Feb 18, 2016 at 7:58 PM, Catalin Marinas
> <catalin.marinas@arm.com> wrote:
> >
> > On Thu, Feb 18, 2016 at 07:48:35PM +0800, Zhi-zhou Zhang wrote:
> > > From: zhizhou <zhizhou.zh@gmail.com>
> > >
> > > This patch is based on the implementation of arm. The generic
> > > current_pt_regs is implemented with current->stack. It need to access
> > > memory that would be too expensive.
> >
> > Do you have any performance numbers?
>
> I'm using QEMU, so no. Actually this macro isn't heavily used. I just
> think using the generic
> implementation is not very nice. It get task_struct from sp_el0, then
> get stack(which is
> equal to sp_el0) from task_struct. There are two unnecessary memory accesses.

I'd much rather use the generic implementation unless there's a compelling
reason not to. "I think it's not very nice" doesn't really cut it for me!

Will

\
 
 \ /
  Last update: 2016-02-19 12:21    [W:0.061 / U:0.376 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site