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 7C9C11DF991 for ; Sat, 19 Apr 2025 17:28:26 +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=1745083706; cv=none; b=CqVBtZ+5jAzM/ncAgS/PXIe7Y62dDs5iCq2Iva4uAdasoOrQIAIieWYP0SzzajHoWBQ/HNpm3iWSUoKxi/eRo2x4udsP0lPckR3jNqNEP7wg7FJXXLpsBRceM5EJChYPaWVFaH51TTVP4+IuAdKz0p3WpFc4RTRml9hCxAG1TuU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745083706; c=relaxed/simple; bh=HO6bNgwZ6Z25hu73jBi7/XBCBhOiGkqDksIbWNEiP54=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Aj1q7kwQlnqvh2kLbV+hfBSzy7nfaDpCitqns9AgxN6IM/lM83bZPaVmdj144WmLV3eMnAeiSACLz+x2xo+t89yTFT/J7Km4OdYJXi43IR7pnixxdX2jj3AgUnbDUtf9cRNj1Ch9SpzvdN+PbX1W1SuP7OkmyMHHeytfUOHn/8k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GnczJQbX; 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="GnczJQbX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4B8A1C4CEED; Sat, 19 Apr 2025 17:28:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1745083706; bh=HO6bNgwZ6Z25hu73jBi7/XBCBhOiGkqDksIbWNEiP54=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GnczJQbXY0LwhjtkkfOCZxO91Hoji9aukTIMVLkR1ixVzbNTM82QyM+ZJx5UG8nNN asUmHXALE4AeTAfAa3OUozq1uiKHj76Alw5UxEav2FoGohV5NypnWfNEARHoF1WbcU CdTA+/udYObAf2b7YCQuKflWL133rtkdjUat7lLzn4/xpQ3g99tTO6M5qHKuFug8E5 F1Hnmw7X+r3wy8M4o6ylI+NT8pzs5YPu5Je19zKDo/oFflZ2+kGoBrD0/FphzUwkEC uZEc2qmosrmQ/KppZB2KODNaAxcaN2dkE/smizYDO01pfaPeL10QzWjHaPlQZrl/Cq rmi92KAKri15A== From: cel@kernel.org To: NeilBrown , Jeff Layton , Olga Kornievskaia , Dai Ngo , Tom Talpey Cc: , Chuck Lever Subject: [PATCH v2 05/10] sunrpc: Replace the rq_bvec array with dynamically-allocated memory Date: Sat, 19 Apr 2025 13:28:13 -0400 Message-ID: <20250419172818.6945-6-cel@kernel.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250419172818.6945-1-cel@kernel.org> References: <20250419172818.6945-1-cel@kernel.org> Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Chuck Lever As a step towards making NFSD's maximum rsize and wsize variable at run-time, replace the fixed-size rq_bvec[] array in struct svc_rqst with a chunk of dynamically-allocated memory. The rq_bvec[] array contains enough bio_vecs to handle each page in a maximum size RPC message. On a system with 8-byte pointers and 4KB pages, pahole reports that the rq_bvec[] array is 4144 bytes. Replacing it with a single pointer reduces the size of struct svc_rqst to about 1240 bytes, or just over 19 cache lines. Signed-off-by: Chuck Lever --- include/linux/sunrpc/svc.h | 2 +- net/sunrpc/svc.c | 7 +++++++ net/sunrpc/svcsock.c | 7 +++---- 3 files changed, 11 insertions(+), 5 deletions(-) diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h index 72d016772711..a524564094d6 100644 --- a/include/linux/sunrpc/svc.h +++ b/include/linux/sunrpc/svc.h @@ -208,7 +208,7 @@ struct svc_rqst { struct folio_batch rq_fbatch; struct kvec *rq_vec; - struct bio_vec rq_bvec[RPCSVC_MAXPAGES]; + struct bio_vec *rq_bvec; __be32 rq_xid; /* transmission id */ u32 rq_prog; /* program number */ diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c index 5808d4b97547..0741e506c35c 100644 --- a/net/sunrpc/svc.c +++ b/net/sunrpc/svc.c @@ -675,6 +675,7 @@ static void svc_rqst_free(struct svc_rqst *rqstp) { folio_batch_release(&rqstp->rq_fbatch); + kfree(rqstp->rq_bvec); kfree(rqstp->rq_vec); svc_release_buffer(rqstp); if (rqstp->rq_scratch_page) @@ -719,6 +720,12 @@ svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool, int node) if (!rqstp->rq_vec) goto out_enomem; + rqstp->rq_bvec = kcalloc_node(rqstp->rq_maxpages, + sizeof(struct bio_vec), + GFP_KERNEL, node); + if (!rqstp->rq_bvec) + goto out_enomem; + rqstp->rq_err = -EAGAIN; /* No error yet */ serv->sv_nrthreads += 1; diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c index 72e5a01df3d3..c846341bb08c 100644 --- a/net/sunrpc/svcsock.c +++ b/net/sunrpc/svcsock.c @@ -713,8 +713,7 @@ static int svc_udp_sendto(struct svc_rqst *rqstp) if (svc_xprt_is_dead(xprt)) goto out_notconn; - count = xdr_buf_to_bvec(rqstp->rq_bvec, - ARRAY_SIZE(rqstp->rq_bvec), xdr); + count = xdr_buf_to_bvec(rqstp->rq_bvec, rqstp->rq_maxpages, xdr); iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, rqstp->rq_bvec, count, rqstp->rq_res.len); @@ -1219,8 +1218,8 @@ static int svc_tcp_sendmsg(struct svc_sock *svsk, struct svc_rqst *rqstp, memcpy(buf, &marker, sizeof(marker)); bvec_set_virt(rqstp->rq_bvec, buf, sizeof(marker)); - count = xdr_buf_to_bvec(rqstp->rq_bvec + 1, - ARRAY_SIZE(rqstp->rq_bvec) - 1, &rqstp->rq_res); + count = xdr_buf_to_bvec(rqstp->rq_bvec + 1, rqstp->rq_maxpages, + &rqstp->rq_res); iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, rqstp->rq_bvec, 1 + count, sizeof(marker) + rqstp->rq_res.len); -- 2.49.0