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 A0088277C9A for ; Wed, 22 Oct 2025 21:25:41 +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=1761168341; cv=none; b=K/8vXKFkxREUSogk+1fd3mgaZQT+SeNaw/QOEfoQ1c5L9m2Gbw89GUsB6iomRsq4+7Oa4tjyEO1lwdD6ioNkfLK++/z0GSWL1uS5LeXyXOjeSrJ4NOz8ngZOkCd3/WWMrXDHiJKA1KF3u/wf9hpPwpiHkrSgHxuZuD9BZokZFPI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761168341; c=relaxed/simple; bh=9wZB7A3Ymy4+9jdF4as6jX0kQ33fL/2H3xQ5cqTXGKA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Bu3zBZSCH06bGO639xrs4LlWgY3CbeS/OdtcJJSC9gahxctOpu0ZVI+k6rrvxFwlqzxP9J6UwOY2/NjB0mzwtC8v1oyUaxdmH1qh8v8DV6wGfIUnMvFUy0IHix96RoqKnBNcOBXmCpornvLmRDrQCtbk5HJTymE/KuBkEMZBmys= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=n2dYJAfD; 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="n2dYJAfD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D9B0FC4CEE7; Wed, 22 Oct 2025 21:25:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1761168341; bh=9wZB7A3Ymy4+9jdF4as6jX0kQ33fL/2H3xQ5cqTXGKA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=n2dYJAfDmGCUIWGKWmwqDvFtswW91fYO2E/gU5Djw/ekFDI/8BM5VEYU+8f4FDD6e kD1PWHLpBfdL+ViSojDgdtSSEc4SlXfrdZ9P8iyWIP3vaLfAueVvM+xSiGlYGKv+eI BiXerJXw8za1L4ag0v/c6PYdUao0tyy8CXP6x2c+06ZOAQ///cmzgIweKhE/KMzKrr 1bOswQmmfnnVpBMh120p/tn0vrXp95dlaNcUyS44hrog4b+OVdDiHkfqCxHyyBfbk3 qz8eYRnNooS/BZN8aoCJz7+lkiT89Jf0v99UbLdEq+TUlrH74bAgKg6MvSZoaZwzhk 73ZzxJ3Hq8/9Q== Date: Wed, 22 Oct 2025 17:25:39 -0400 From: Mike Snitzer To: Chuck Lever Cc: NeilBrown , Jeff Layton , Olga Kornievskaia , Dai Ngo , Tom Talpey , linux-nfs@vger.kernel.org, Chuck Lever Subject: Re: [PATCH v6 5/5] svcrdma: Mark Read chunks Message-ID: References: <20251022192208.1682-1-cel@kernel.org> <20251022192208.1682-6-cel@kernel.org> Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251022192208.1682-6-cel@kernel.org> On Wed, Oct 22, 2025 at 03:22:08PM -0400, Chuck Lever wrote: > From: Chuck Lever > > The upper layer may want to know when the receive buffer's .pages > array is guaranteed to contain only an opaque payload. This permits > the upper layer to optimize its buffer handling. > > NB: Since svc_rdma_recvfrom.c is under net/, we use the comment > style that is preferred in the networking layer. > > Reviewed-by: Jeff Layton > Signed-off-by: Chuck Lever > --- > net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c > index e7e4a39ca6c6..b1a0c72f73de 100644 > --- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c > +++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c > @@ -815,6 +815,11 @@ static void svc_rdma_read_complete_one(struct svc_rqst *rqstp, > buf->page_len = length; > buf->len += length; > buf->buflen += length; > + > + /* Transport guarantees that only the chunk payload > + * appears in buf->pages. > + */ > + buf->flags |= XDRBUF_READ; > } > > /* Finish constructing the RPC Call message in rqstp::rq_arg. > -- > 2.51.0 > > This patch header leaves me unclear on your thinking for upper layer optimization that would look for XDRBUF_READ. I see rpcrdma_marshal_req() is checking XDRBUF_READ but... I'm left hoping for a clearer payoff on this change's benefit (and relation to the rest of the patchset).