Re: FAILED: patch "[PATCH] mm/damon/core: merge regions aggressively when max_nr_regions" failed to apply to 6.1-stable tree

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Jul 15, 2024 at 09:57:17AM -0700, SeongJae Park wrote:
> Hi Greg,
> 
> On Mon, 15 Jul 2024 13:34:48 +0200 <gregkh@linuxfoundation.org> wrote:
> 
> > 
> > The patch below does not apply to the 6.1-stable tree.
> > If someone wants it applied there, or to any other stable or longterm
> > tree, then please email the backport, including the original git commit
> > id to <stable@vger.kernel.org>.
> > 
> > To reproduce the conflict and resubmit, you may use the following commands:
> > 
> > git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
> > git checkout FETCH_HEAD
> > git cherry-pick -x 310d6c15e9104c99d5d9d0ff8e5383a79da7d5e6
> 
> But this doesn't reproduce the failure on my machine, like below?
> 
>     $ git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
>     [...]
>     $ git checkout FETCH_HEAD
>     [...]
>     HEAD is now at cac15753b8ce Linux 6.1.99
>     $ git cherry-pick -x 310d6c15e9104c99d5d9d0ff8e5383a79da7d5e6
>     Auto-merging mm/damon/core.c
>     [detached HEAD ecd04159c5f3] mm/damon/core: merge regions aggressively when max_nr_regions is unmet
>      Date: Mon Jun 24 10:58:14 2024 -0700
>      1 file changed, 19 insertions(+), 2 deletions(-)

Try building it:

  DESCEND objtool
  CALL    scripts/checksyscalls.sh
  CC      mm/damon/core.o
In file included from ./include/linux/kernel.h:26,
                 from ./arch/x86/include/asm/percpu.h:27,
                 from ./arch/x86/include/asm/preempt.h:6,
                 from ./include/linux/preempt.h:79,
                 from ./include/linux/spinlock.h:56,
                 from ./include/linux/swait.h:7,
                 from ./include/linux/completion.h:12,
                 from ./include/linux/damon.h:11,
                 from mm/damon/core.c:10:
mm/damon/core.c: In function ‘kdamond_merge_regions’:
./include/linux/minmax.h:20:35: error: comparison of distinct pointer types lacks a cast [-Werror]
   20 |         (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
      |                                   ^~
./include/linux/minmax.h:26:18: note: in expansion of macro ‘__typecheck’
   26 |                 (__typecheck(x, y) && __no_side_effects(x, y))
      |                  ^~~~~~~~~~~
./include/linux/minmax.h:36:31: note: in expansion of macro ‘__safe_cmp’
   36 |         __builtin_choose_expr(__safe_cmp(x, y), \
      |                               ^~~~~~~~~~
./include/linux/minmax.h:52:25: note: in expansion of macro ‘__careful_cmp’
   52 | #define max(x, y)       __careful_cmp(x, y, >)
      |                         ^~~~~~~~~~~~~
mm/damon/core.c:946:29: note: in expansion of macro ‘max’
  946 |                 threshold = max(1, threshold * 2);
      |                             ^~~
cc1: all warnings being treated as errors
make[3]: *** [scripts/Makefile.build:250: mm/damon/core.o] Error 1
make[2]: *** [scripts/Makefile.build:503: mm/damon] Error 2
make[1]: *** [scripts/Makefile.build:503: mm] Error 2