Re: [PATCH 2/2] selftests/mm: restore hidden hugetlb reservation scenarios

[Mike Rapoport <rppt@kernel.org>]

On Tue, Sep 01, 2026 at 05:37:48PM -0700, Andrew Morton wrote:
> On Tue, 14 Jul 2026 10:16:30 +0800 Song Hu <husong@kylinos.cn> wrote:
> 
> > A stray 'continue' in the main loop of charge_reserved_hugetlb.sh made
> > the "more than reservation", "more than cgroup limit", and "multiple
> > cgroups" scenarios unreachable, so they never ran.
> > 
> > Remove it so the first two run again.
> 
> OK.
> 
> > The third,
> > run_multiple_cgroup_test(), is separately broken -- a backslash
> > line-continuation breaks its local declarations and its hugetlb
> > reservation accounting does not charge as expected -- and has never run
> > in CI; skip it explicitly with a comment until fixed.
> 
> That's reasonable.  This code was added by Mina six years ago.  But
> he's still around so let's bug him with a cc ;)

And this code breaks our CI e.g:

https://github.com/linux-mm/linux-mm/actions/runs/33040981840/job/98414290236

> > Also correct two
> > `[[ "$method" == 2"" ]]` typos (harmless empty-string concatenation)
> > to plain `2`.
> 
> OK.
> 
> 
> 
> From: Song Hu <husong@kylinos.cn>
> Subject: selftests/mm: restore hidden hugetlb reservation scenarios
> Date: Tue, 14 Jul 2026 10:16:30 +0800
> 
> A stray 'continue' in the main loop of charge_reserved_hugetlb.sh made the
> "more than reservation", "more than cgroup limit", and "multiple cgroups"
> scenarios unreachable, so they never ran.
> 
> Remove it so the first two run again.  The third,
> run_multiple_cgroup_test(), is separately broken -- a backslash
> line-continuation breaks its local declarations and its hugetlb
> reservation accounting does not charge as expected -- and has never run in
> CI; skip it explicitly with a comment until fixed.  Also correct two `[[
> "$method" == 2"" ]]` typos (harmless empty-string concatenation) to plain
> `2`.
> 
> Link: https://lore.kernel.org/20260714021630.1063823-1-husong@kylinos.cn
> Signed-off-by: Song Hu <husong@kylinos.cn>
> Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
> Cc: David Hildenbrand <david@kernel.org>
> Cc: Liam R. Howlett <liam@infradead.org>
> Cc: Lorenzo Stoakes <ljs@kernel.org>
> Cc: Michal Hocko <mhocko@suse.com>
> Cc: Mike Rapoport <rppt@kernel.org>
> Cc: Muchun Song <muchun.song@linux.dev>
> Cc: Oscar Salvador <osalvador@suse.de>
> Cc: Shuah Khan <shuah@kernel.org>
> Cc: Suren Baghdasaryan <surenb@google.com>
> Cc: Vlastimil Babka <vbabka@kernel.org>
> Cc: Mina Almasry <almasrymina@google.com>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> ---
> 
>  tools/testing/selftests/mm/charge_reserved_hugetlb.sh |   14 +++++++---
>  1 file changed, 11 insertions(+), 3 deletions(-)
> 
> --- a/tools/testing/selftests/mm/charge_reserved_hugetlb.sh~selftests-mm-restore-hidden-hugetlb-reservation-scenarios
> +++ a/tools/testing/selftests/mm/charge_reserved_hugetlb.sh
> @@ -439,11 +439,11 @@ for populate in "" "-o"; do
>          fi
>  
>          # Skip populated shmem tests. Doesn't seem to be supported.
> -        if [[ "$method" == 2"" ]] && [[ "$populate" == "-o" ]]; then
> +        if [[ "$method" == 2 ]] && [[ "$populate" == "-o" ]]; then
>            continue
>          fi
>  
> -        if [[ "$method" == 2"" ]] && [[ "$reserve" == "-n" ]]; then
> +        if [[ "$method" == 2 ]] && [[ "$reserve" == "-n" ]]; then
>            continue
>          fi
>  
> @@ -496,7 +496,6 @@ for populate in "" "-o"; do
>          echo 'PASS'
>  
>          cleanup
> -        continue
>          echo
>          echo
>          echo
> @@ -530,6 +529,15 @@ for populate in "" "-o"; do
>  
>          cleanup
>  
> +        # The "multiple cgroups" scenario (run_multiple_cgroup_test) is
> +        # multiply broken and has never run in CI: a backslash
> +        # line-continuation breaks its local declarations, it passes
> +        # reservation sizes in bytes rather than pages (unlike
> +        # run_test), and its assertions compare page counts to byte
> +        # values. Skip it until properly rewritten; the two scenarios
> +        # above are restored by this change.
> +        continue
> +
>          echo
>          echo
>          echo
> _
> 
> 

-- 
Sincerely yours,
Mike.