On Tue, Jun 01, 2021 at 01:24:39AM -0700, 'Bill Wendling' via Clang Built Linux wrote:

On Mon, May 31, 2021 at 1:29 PM Nathan Chancellor [off-list ref] wrote:

quoted

On 5/31/2021 1:20 PM, Bill Wendling wrote:

quoted

Future PGO features may create other files in /sys/kernel/debug/pgo. So
rename the kernel's raw profile data file to "vmlinux.profraw" to make
which part of the kernel the file is for more explicit.

Note that future files in /sys/kernel/debug/pgo should follow a similar
naming convention.

Signed-off-by: Bill Wendling <morbo@google.com>

Guess this clears up my confusion around the module patches :)

To clarify, Jarmo did those patches on his own. I just wanted to
clarify the naming convention. :-)

Is the expectation that there would be 1 file per module in
/sys/kernel/debug/pgo/ after the modules patch?

-bw

quoted

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

quoted

---
  Documentation/dev-tools/pgo.rst | 6 +++---
  kernel/pgo/Kconfig              | 7 ++++---
  kernel/pgo/fs.c                 | 2 +-
  3 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/Documentation/dev-tools/pgo.rst b/Documentation/dev-tools/pgo.rst
index b7f11d8405b7..0200449c4843 100644
--- a/Documentation/dev-tools/pgo.rst
+++ b/Documentation/dev-tools/pgo.rst

@@ -76,7 +76,7 @@ The PGO kernel support creates the following files in debugfs:
  ``/sys/kernel/debug/pgo/reset``
      Global reset file: resets all coverage data to zero when written to.

-``/sys/kernel/debug/profraw``
+``/sys/kernel/debug/pgo/vmlinux.profraw``
      The raw PGO data that must be processed with ``llvm_profdata``.

@@ -108,7 +108,7 @@ using the result to optimize the kernel:

     .. code-block:: sh

-      $ cp -a /sys/kernel/debug/pgo/profraw /tmp/vmlinux.profraw
+      $ cp -a /sys/kernel/debug/pgo/vmlinux.profraw /tmp/vmlinux.profraw

And if so, these instructions would change (in the future) to something
like:

     $ cp -a /sys/kernel/debug/pgo/*.profraw /tmp/prof/

?

-Kees

-- 
Kees Cook