lkml.org 
[lkml]   [2014]   [Feb]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    SubjectRe: [PATCH v3 1/6] arm64: Add ftrace support
    Date
    On Wednesday 12 February 2014, Takahiro Akashi wrote:
    > > If I build a large "randconfig" kernel or "allyesconfig", the kernel image
    > > size exceeds 32MB, which means I can no longer link callers with a 26
    > > bit signed immediate argument like the "bl _mcount" here. For any other
    > > function calls, "gcc -mlong-calls" can be used to work around this, but
    > > this particular instance is created by inserting assembly statements
    > > into the output without considering the long-call options. Is there
    > > a way to get the kernel to link anyway?
    >
    > I hope that this won't happen on arm64 because a branch offset range is
    > +/- 128MB.

    Yes, we should be safe for the next decade on arm64. My question was really
    about arm32 here, hoping someone has an idea.

    > > > +#ifdef CONFIG_FUNCTION_GRAPH_TRACER
    > >
    > > Here, again, you an remove the #ifdef by making the entire file built
    > > only for CONFIG_FUNCTION_GRAPH_TRACER.
    >
    > You're right as far as patch [1/6] is concerned, but once patch [2/6] is
    > applied,
    > this file (ftrace.c) may be compiled even if CONFIG_FUNCTION_GRAPH_TRACER
    > is not enabled. (That is CONFIG_DYNAMIC_FTRACE.)
    > Sorry for any confusion by poorly-divided patchset.

    No, that was my fault. I saw it later after I had already sent out the
    message.

    Arnd


    \
     
     \ /
      Last update: 2014-02-12 12:21    [W:2.108 / U:0.024 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site