lkml.org 
[lkml]   [2011]   [Mar]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH 0/2] jump label: update for .39
    On 03/10/2011 03:16 PM, Steven Rostedt wrote:
    > On Thu, 2011-03-10 at 17:48 -0500, Mathieu Desnoyers wrote:
    >> * Steven Rostedt (rostedt@goodmis.org) wrote:
    >>> On Thu, 2011-03-10 at 16:22 -0500, Mathieu Desnoyers wrote:
    >>>
    >>>>> Anyway, I think the best thing for now is to have Jason add
    >>>>> the .align(sizeof(long)) in the inline assembly for all locations and be
    >>>>> done with it.
    >>>>
    >>>> You seem to be contradicting yourself here. I'm concerned about having
    >>>> "structures" of a size not power of two. Can we simply either
    >>>
    >>> But we don't have structures. We have data that has been allocated in
    >>> assembly. Come to think of it, it may be best to keep these as
    >>> ".align 4".
    >>
    >> The .align 4 is certainly not the right answer, because it will trigger
    >> unaligned accesses on some 64-bit architectures, as we have faced with
    >> trace event.
    >
    > Will it? Seems that sparc does this regardless.
    >
    > Remember, this is 3 natural word sized objects, and vmlinux.ld starts
    > the section off with .ALIGN 8, hence, the section is already 8 byte
    > aligned, all objects within this section are 8 bytes (for 64bit archs,
    > and 4 bytes for 32bit), why would saying ".align 4" cause the linker to
    > add holes to make it 4 byte aligned when it is already 8 byte aligned.
    > The ".align 4" should work with both 32bit and 64bit archs.
    >

    It should work, but it hurts my eyes to see the source code forcing a
    64-bit word to 32-bit alignment.

    David Daney


    \
     
     \ /
      Last update: 2011-03-11 00:27    [W:4.767 / U:0.188 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site