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Date:   Sun, 21 Mar 2021 10:28:49 +0200
From:   Leon Romanovsky <leon@kernel.org>
To:     Dmitry Vyukov <dvyukov@google.com>
Cc:     davem@davemloft.net, edumazet@google.com, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] net: make unregister netdev warning timeout configurable
Message-ID: <YFcDwbmecMo0o4na@unreal>
References: <20210320142851.1328291-1-dvyukov@google.com>
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On Sat, Mar 20, 2021 at 03:28:51PM +0100, Dmitry Vyukov wrote:
> netdev_wait_allrefs() issues a warning if refcount does not drop to 0
> after 10 seconds. While 10 second wait generally should not happen
> under normal workload in normal environment, it seems to fire falsely
> very often during fuzzing and/or in qemu emulation (~10x slower).
> At least it's not possible to understand if it's really a false
> positive or not. Automated testing generally bumps all timeouts
> to very high values to avoid flake failures.
> Make the timeout configurable for automated testing systems.
> Lowering the timeout may also be useful for e.g. manual bisection.
> The default value matches the current behavior.
> 
> Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
> Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=211877
> Cc: netdev@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> ---
>  net/Kconfig    | 12 ++++++++++++
>  net/core/dev.c |  4 +++-
>  2 files changed, 15 insertions(+), 1 deletion(-)
> 

Our verification team would like to see this change too.

Thanks,
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>