Received-SPF: softfail (google.com: domain of transitioning linux-kernel-owner@vger.kernel.org does not designate 23.128.96.19 as permitted sender) client-ip=23.128.96.19;
MIME-Version: 1.0
References: <20220221232542.1481315-1-andrzej.hajda@intel.com> <20220221232542.1481315-8-andrzej.hajda@intel.com>
In-Reply-To: <20220221232542.1481315-8-andrzej.hajda@intel.com>
From:   Eric Dumazet <edumazet@google.com>
Date:   Mon, 21 Feb 2022 15:54:12 -0800
Message-ID: <CANn89i+E3z-iXSJh8316KSycYk2VTS-n0E=tAOj23fuDSi1Zjg@mail.gmail.com>
Subject: Re: [PATCH v3 07/11] lib/ref_tracker: remove warnings in case of
 allocation failure
To:     Andrzej Hajda <andrzej.hajda@intel.com>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
        netdev <netdev@vger.kernel.org>,
        Jani Nikula <jani.nikula@linux.intel.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Lucas De Marchi <lucas.demarchi@intel.com>,
        Chris Wilson <chris.p.wilson@intel.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Jakub Kicinski <kuba@kernel.org>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Mon, Feb 21, 2022 at 3:26 PM Andrzej Hajda <andrzej.hajda@intel.com> wrote:
>
> Library can handle allocation failures. To avoid allocation warnings
> __GFP_NOWARN has been added everywhere. Moreover GFP_ATOMIC has been
> replaced with GFP_NOWAIT in case of stack allocation on tracker free
> call.
>
> Signed-off-by: Andrzej Hajda <andrzej.hajda@intel.com>
> ---
>  lib/ref_tracker.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/lib/ref_tracker.c b/lib/ref_tracker.c
> index 2ef4596b6b36f..cae4498fcfd70 100644
> --- a/lib/ref_tracker.c
> +++ b/lib/ref_tracker.c
> @@ -189,7 +189,7 @@ int ref_tracker_alloc(struct ref_tracker_dir *dir,
>         unsigned long entries[REF_TRACKER_STACK_ENTRIES];
>         struct ref_tracker *tracker;
>         unsigned int nr_entries;
> -       gfp_t gfp_mask = gfp;
> +       gfp_t gfp_mask = gfp | __GFP_NOWARN;

SGTM

>         unsigned long flags;
>
>         WARN_ON_ONCE(dir->dead);
> @@ -237,7 +237,8 @@ int ref_tracker_free(struct ref_tracker_dir *dir,
>                 return -EEXIST;
>         }
>         nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 1);
> -       stack_handle = stack_depot_save(entries, nr_entries, GFP_ATOMIC);
> +       stack_handle = stack_depot_save(entries, nr_entries,
> +                                       GFP_NOWAIT | __GFP_NOWARN);

Last time I looked at this, __GFP_NOWARN was enforced in __stack_depot_save()

>
>         spin_lock_irqsave(&dir->lock, flags);
>         if (tracker->dead) {
> --
> 2.25.1
>