Re: [PATCH 2/2 v2] perf tools: Enable bpf prologue for arm64

[Hekuang]

hi,

å 2017/1/27 3:31, Arnaldo Carvalho de Melo åé:
> Em Thu, Jan 26, 2017 at 04:52:12PM +0000, Will Deacon escreveu:
> > On Thu, Jan 26, 2017 at 10:49:16AM +0900, Masami Hiramatsu wrote:
> > > On Wed, 25 Jan 2017 13:32:01 +0000
> > > Will Deacon <will.deacon@xxxxxxx> wrote:
> > >
> > > > On Wed, Jan 25, 2017 at 07:23:11AM +0000, He Kuang wrote:
> > > > > Since HAVE_KPROBES can be enabled in arm64, this patch introduces
> > > > > regs_query_register_offset() to convert register name to offset for
> > > > > arm64, so the BPF prologue feature is ready to use.
> > > > >
> > > > > This patch also changes the 'dwarfnum' to 'offset' in register table,
> > > > > so the related functions are consistent with x86.
> > > > Wouldn't it be an awful lot simpler just to leave the code as-is, and
> > > > implement regs_query_register_offset in the same way that we implement
> > > > get_arch_regstr but return the dwarfnum?
> > > No, since the offset is not same as dwarfnum.
> > >
> > > With this style, the index of array becomes the dwarfnum (the index of
> > > each register defined by DWARF) and the "offset" member means the
> > > byte-offset of the register in (user_)pt_regs. Those should be different.
> > Ok, then do it as two patches then, rather than introduce functionality
> > along with the renaming.
> >
> > > > I don't really see the point of all the refactoring.
> > > Also, from the maintenance point of view, this rewrite work makes
> > > the code simply similar to x86 implementation, that will be easier to
> > > maintain :)
> > Right, apart from the two howling bugs in the version that was nearly merged
> > initially :p. I tend to err on the "if it ain't broke, don't fix it" side
> > of the argument but if you really want the refactoring lets keep it as a
> > separate change.
> So, He, can you do that? How do we proceed?
>
> - Arnaldo

I split the patch as Will suggested and resend them. Sorry for
late response, just back from Spring festival.