From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E4D082FFF89 for ; Wed, 14 Jan 2026 02:30:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768357810; cv=none; b=cSlP5ruuLcJvwsyPUJUuYeS6J9iC99260fC+voS+kPwcXbMiJniUNMzyjrVclsErey88iNAq+HDlxiQgwoVaCyH2roxgxFcbYnhcS5FIQN/xsv2GLePLh5ljCbITogeEHBQiBpjgeHAa8BAdYAYwWfCS/YmOsbWxDrCoBamYUiQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768357810; c=relaxed/simple; bh=rB/Pc+MocA2Hrim5hkGRBvmByotgqJEjphJuv83p7GU=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=P0Iz39ywDYB42f+FF+FlXwzBgw+WDSKgW8Ht7iBbIxwBdwznn8i5P8rTLP7mi4U4kqB6lmhbpPYp9eZww8M4Qg37MO485UVXVr2gcXTS/YFYTM3OiJFB73kk9M1oq10wQzW0SsMgcPerUnKzMn4Ww3z7rbJXO3yoxUsxcyvBQ4E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=B8B5661k; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="B8B5661k" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 237AFC116C6; Wed, 14 Jan 2026 02:30:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1768357809; bh=rB/Pc+MocA2Hrim5hkGRBvmByotgqJEjphJuv83p7GU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=B8B5661k8znJFACcufjqnHa2ZHBM8hAzYBcDVB/ERqQiTMpAv0mRegL5U1ZiH3s5Z 0WnTRxt9H1x/o7eB04sHWTW5Aa+WOW/20PW7ZCCXi5Af7WLHugww32EPm/UkjgLa8Y 5Y/+QiJ3X7Mm1RLjbhpdVgXfBq+UOE0m7S4hA1XcwMtp8hNv6ZV2Fg155ORYxv7P0K NodBXJxt2N5FtuT/aaFShj3AV+yGx44tpa3OFbiBJk0i36IN7g6bMKJnOSevWDMp+A Rol/BehrbsvLyjZck9Bf2UC+JkBxDD8x3HQPCeCsOSKUrfeS+71Ru1X2c+/9mKIVyL nI39q9o80kzEw== Date: Tue, 13 Jan 2026 18:30:08 -0800 From: Jakub Kicinski To: Eric Dumazet Cc: "David S . Miller" , Paolo Abeni , Simon Horman , netdev@vger.kernel.org, eric.dumazet@gmail.com Subject: Re: [PATCH net-next] net: minor __alloc_skb() optimization Message-ID: <20260113183008.15175891@kernel.org> In-Reply-To: References: <20260113131017.2310584-1-edumazet@google.com> <20260113174417.32b13cc1@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Wed, 14 Jan 2026 02:54:10 +0100 Eric Dumazet wrote: > We could keep it for a while, WDYT of > > diff --git a/net/core/skbuff.c b/net/core/skbuff.c > index 77508cf7c41e829a11a988d8de3d2673ff1ff121..ccd287ff46e91c2548483c51fa32fc6167867940 > 100644 > --- a/net/core/skbuff.c > +++ b/net/core/skbuff.c > @@ -458,7 +458,8 @@ static void __build_skb_around(struct sk_buff > *skb, void *data, > /* frag_size == 0 is considered deprecated now. Callers > * using slab buffer should use slab_build_skb() instead. > */ > - if (WARN_ONCE(size == 0, "Use slab_build_skb() instead")) > + if (IS_ENABLED(CONFIG_DEBUG_NET) && > + WARN_ONCE(size == 0, "Use slab_build_skb() instead")) > data = __slab_build_skb(data, &size); Probably not worth it. People who use relevant HW + 3 year old kernels (I just checked, we added the warning in Dec 2022) likely don't set DEBUG_NET either. That said looks like the warning landed in 6.2, narrowly missing the v6.1 LTS. I suppose v6.1 may still be used by some "enterprise-ish" distroes. I guess we should wait another year :( Sorry for the noise :(