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 B3EC819ADBA; Tue, 28 Oct 2025 14:44:51 +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=1761662691; cv=none; b=Q4YjKzSBUlUWJceTXkd8fUe9PF/oNgvt+YMoMW9FVvMNzUXAC6hZn68/4SyjmIXBexTQoT90IssE+9MkqYxG4CLJc/By/3UH7XyLRetagus8MirxzzQcSkjridSlZomk7EyO7E2q2dkdqUoYv3Diy7o/fpcNeDVT9HkYg2KODaw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761662691; c=relaxed/simple; bh=fuPk2vf7KDqzwHVW9GxJh9JwUPAx4o37mqyOQ65OjsA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=GMeX8y0MkD8NdTHYsUQQna+/0gOaGTWIIvDbtE+Wrju7lWNiBxYgdpQ3hS1Y+ccFLXHOzJutwlGMJb6kdlsWX2rqSNoTBSFNtHiA6OaMJbS8+OjLA/Lg1Qju0Dp0jDKOnct50nUaYJsyz/t3p838dXEskK3UTIaHWcjw1oXjg4g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TLAljYi1; 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="TLAljYi1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5B640C4CEE7; Tue, 28 Oct 2025 14:44:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1761662691; bh=fuPk2vf7KDqzwHVW9GxJh9JwUPAx4o37mqyOQ65OjsA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=TLAljYi1+jk/WhrIiqhIINxvGFpBqh32vlKGDHG3QuwonoRqUlG1ghczULAFAyrdZ ATscMcsqe7wIKzxij7h9z3ekG5i2WZG3pH3f7tvImg/mEsisU2gmkBGZNdADN5B8EO 36USKwSp68WptmLr+K8Dn2Xbgq6KkADMhn6czbx7Hmji1nIGXlXCTSXTDe3rDCf8M6 F1ONo9On4+Nqyr7Mo+QTsHsQLHsPLhTR6mPbYcmM6N9cK0QYdYNWGsiYMgKndo4b27 sRn5ZioW1MTT6HKYY304EHGC7aUDlUmnIlMbqTOGpfQ0/y9MFU/McePA4jY5jLoGbx TWrgkcXFT5Xag== Date: Tue, 28 Oct 2025 14:44:44 +0000 From: Simon Horman To: Jason Xing Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, bjorn@kernel.org, magnus.karlsson@intel.com, maciej.fijalkowski@intel.com, jonathan.lemon@gmail.com, sdf@fomichev.me, ast@kernel.org, daniel@iogearbox.net, hawk@kernel.org, john.fastabend@gmail.com, joe@dama.to, willemdebruijn.kernel@gmail.com, bpf@vger.kernel.org, netdev@vger.kernel.org, Jason Xing Subject: Re: [PATCH net-next v3 1/9] xsk: introduce XDP_GENERIC_XMIT_BATCH setsockopt Message-ID: References: <20251021131209.41491-1-kerneljasonxing@gmail.com> <20251021131209.41491-2-kerneljasonxing@gmail.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Sat, Oct 25, 2025 at 05:08:39PM +0800, Jason Xing wrote: > Hi Simon, > > On Fri, Oct 24, 2025 at 9:30 PM Simon Horman wrote: > > > > On Tue, Oct 21, 2025 at 09:12:01PM +0800, Jason Xing wrote: > > > > ... > > > > > index 7b0c68a70888..ace91800c447 100644 > > > > ... > > > > > @@ -1544,6 +1546,55 @@ static int xsk_setsockopt(struct socket *sock, int level, int optname, > > > WRITE_ONCE(xs->max_tx_budget, budget); > > > return 0; > > > } > > > + case XDP_GENERIC_XMIT_BATCH: > > > + { > > > + struct xsk_buff_pool *pool = xs->pool; > > > + struct xsk_batch *batch = &xs->batch; > > > + struct xdp_desc *descs; > > > + struct sk_buff **skbs; > > > + unsigned int size; > > > + int ret = 0; > > > + > > > + if (optlen != sizeof(size)) > > > + return -EINVAL; > > > + if (copy_from_sockptr(&size, optval, sizeof(size))) > > > + return -EFAULT; > > > + if (size == batch->generic_xmit_batch) > > > + return 0; > > > + if (size > xs->max_tx_budget || !pool) > > > + return -EACCES; > > > + > > > + mutex_lock(&xs->mutex); > > > + if (!size) { > > > + kfree(batch->skb_cache); > > > + kvfree(batch->desc_cache); > > > + batch->generic_xmit_batch = 0; > > > + goto out; > > > + } > > > + > > > + skbs = kmalloc(size * sizeof(struct sk_buff *), GFP_KERNEL); > > > + if (!skbs) { > > > + ret = -ENOMEM; > > > + goto out; > > > + } > > > + descs = kvcalloc(size, sizeof(struct xdp_desc), GFP_KERNEL); > > > + if (!descs) { > > > + kfree(skbs); > > > + ret = -ENOMEM; > > > + goto out; > > > + } > > > + if (batch->skb_cache) > > > + kfree(batch->skb_cache); > > > + if (batch->desc_cache) > > > + kvfree(batch->desc_cache); > > > > Hi Jason, > > > > nit: kfree and kvfree are no-ops when passed NULL, > > so the conditions above seem unnecessary. > > Yep, but the checkpatch complains. I thought it might be good to keep > it because normally we need to check the validation of the pointer > first and then free it. WDYT? I don't feel particularly strongly about this. But I would lean to wards removing the if() conditions because they are unnecessary: less is more.