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    SubjectRe: [PATCH 2/2 v2] perf tools: Enable bpf prologue for arm64
    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@arm.com> 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

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