lkml.org 
[lkml]   [2021]   [Feb]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.4 22/35] trace: Use -mcount-record for dynamic ftrace
    Date
    From: Andi Kleen <ak@linux.intel.com>

    commit 96f60dfa5819a065bfdd2f2ba0df7d9cbce7f4dd upstream.

    gcc 5 supports a new -mcount-record option to generate ftrace
    tables directly. This avoids the need to run record_mcount
    manually.

    Use this option when available.

    So far doesn't use -mcount-nop, which also exists now.

    This is needed to make ftrace work with LTO because the
    normal record-mcount script doesn't run over the link
    time output.

    It should also improve build times slightly in the general
    case.
    Link: http://lkml.kernel.org/r/20171127213423.27218-12-andi@firstfloor.org

    Signed-off-by: Andi Kleen <ak@linux.intel.com>
    Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    ---
    scripts/Makefile.build | 6 ++++++
    1 file changed, 6 insertions(+)

    --- a/scripts/Makefile.build
    +++ b/scripts/Makefile.build
    @@ -221,6 +221,11 @@ cmd_modversions_c = \
    endif

    ifdef CONFIG_FTRACE_MCOUNT_RECORD
    +# gcc 5 supports generating the mcount tables directly
    +ifneq ($(call cc-option,-mrecord-mcount,y),y)
    +KBUILD_CFLAGS += -mrecord-mcount
    +else
    +# else do it all manually
    ifdef BUILD_C_RECORDMCOUNT
    ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
    RECORDMCOUNT_FLAGS = -w
    @@ -250,6 +255,7 @@ cmd_record_mcount = \
    $(sub_cmd_record_mcount) \
    fi;
    endif
    +endif

    define rule_cc_o_c
    $(call echo-cmd,checksrc) $(cmd_checksrc) \

    \
     
     \ /
      Last update: 2021-02-22 14:45    [W:2.547 / U:0.272 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site