Re: [PATCH] Collect both user and kernel events for autofdo tests and autoprofiledbootstrap

[Richard Biener <richard.guenther@gmail.com>]

On Fri, Jun 30, 2023 at 7:28 AM Eugene Rozenfeld via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> When we collect just user events for autofdo with lbr we get some events where branch
> sources are kernel addresses and branch targets are user addresses. Without kernel MMAP
> events create_gcov can't make sense of kernel addresses. Currently create_gcov fails if
> it can't map at least 95% of events. We sometimes get below this threshold with just
> user events. The change is to collect both user events and kernel events.

Does this require elevated privileges?  Can we instead "fix" create_gcov here?

> Tested on x86_64-pc-linux-gnu.
>
> ChangeLog:
>
>         * Makefile.in: Collect both kernel and user events for autofdo
>         * Makefile.tpl: Collect both kernel and user events for autofdo
>
> gcc/testsuite/ChangeLog:
>
>         * lib/target-supports.exp: Collect both kernel and user events for autofdo
> ---
>  Makefile.in                           | 2 +-
>  Makefile.tpl                          | 2 +-
>  gcc/testsuite/lib/target-supports.exp | 2 +-
>  3 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/Makefile.in b/Makefile.in
> index f19a9db621e..04307ca561b 100644
> --- a/Makefile.in
> +++ b/Makefile.in
> @@ -404,7 +404,7 @@ MAKEINFO = @MAKEINFO@
>  EXPECT = @EXPECT@
>  RUNTEST = @RUNTEST@
>
> -AUTO_PROFILE = gcc-auto-profile -c 10000000
> +AUTO_PROFILE = gcc-auto-profile --all -c 10000000
>
>  # This just becomes part of the MAKEINFO definition passed down to
>  # sub-makes.  It lets flags be given on the command line while still
> diff --git a/Makefile.tpl b/Makefile.tpl
> index 3a5b7ed3c92..d0fe7e2fb77 100644
> --- a/Makefile.tpl
> +++ b/Makefile.tpl
> @@ -407,7 +407,7 @@ MAKEINFO = @MAKEINFO@
>  EXPECT = @EXPECT@
>  RUNTEST = @RUNTEST@
>
> -AUTO_PROFILE = gcc-auto-profile -c 10000000
> +AUTO_PROFILE = gcc-auto-profile --all -c 10000000
>
>  # This just becomes part of the MAKEINFO definition passed down to
>  # sub-makes.  It lets flags be given on the command line while still
> diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
> index 4d04df2a709..b16853d76df 100644
> --- a/gcc/testsuite/lib/target-supports.exp
> +++ b/gcc/testsuite/lib/target-supports.exp
> @@ -704,7 +704,7 @@ proc check_effective_target_keeps_null_pointer_checks { } {
>  # this allows parallelism of 16 and higher of parallel gcc-auto-profile
>  proc profopt-perf-wrapper { } {
>      global srcdir
> -    return "$srcdir/../config/i386/gcc-auto-profile -m8 "
> +    return "$srcdir/../config/i386/gcc-auto-profile --all -m8 "
>  }
>
>  # Return true if profiling is supported on the target.
> --
> 2.25.1
>