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 700E220FA8F for ; Wed, 16 Apr 2025 15:28:58 +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=1744817338; cv=none; b=O/TMkQews2tuI/a/mN7We05Ckg1KWu6ktKru7NX51vlIB0fGm33n2Zn+Pra2bP7O2AFxwLsaiiSxsVy1abaXvefNKj50Wb0O1ut6i1s9mOjRQMCVenMTl8SYnn6uni9ixd2wXjK4q2pdbuom4ftvVzLTzKbim34cCgHBr77FnVQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744817338; c=relaxed/simple; bh=qPFP7oGu0c544aP1y/hr1yJ5l/51lj0mVvbLatfmbOw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=fbpu6MZhxltQmgjER7Sk/gSfQJNWj5NDaE3N5hQopC3qTx5yysV/qdAPlOnT+avEyA3QkVxCznOeEDa8R+fBRtHPQGt2+klIZxw3q2zdj9PhywqYnny1PnXqMHaCIZULwU+fQax/Jtz0zjdspwNG3pY4vZzFwjiSRBxggzPuswM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=q36HLyII; 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="q36HLyII" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 613ADC4CEE2; Wed, 16 Apr 2025 15:28:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1744817338; bh=qPFP7oGu0c544aP1y/hr1yJ5l/51lj0mVvbLatfmbOw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=q36HLyIIQPgzPVfh+dUMSiQhBWJcp/C77Jc0uqsSEgQcY27qcWaEOLfYLoY70xZF5 xu2s6h7v0PTUMmJnZI/IToGUm43ALX8MK0TbGGwyz0xHGUKmi67ojzptGSgclMS2m9 kEAa24LAno9MCK9az61Zsi6VhZjZLqvrzt4woU5KV9W/H3Yp0b92u+4GuTiWjV+yG3 JnmATJXg6bWsI3bTR7fv+6CFyIq2vNe0PS0XK/ob9bUAoodTiW7/kpLe1K4+EcnsdI bJmZYrBFsu8i2pqlruRETEzU+gmSbghE7J+y4Zroo0ClWpuOA+A9avJIgDjn4CsI1W 6K0Rn+0jlDqiA== From: cel@kernel.org To: NeilBrown , Jeff Layton , Olga Kornievskaia , Dai Ngo , Tom Talpey Cc: , Chuck Lever Subject: [RFC PATCH 1/2] sunrpc: Replace the rq_bvec array with dynamically-allocated memory Date: Wed, 16 Apr 2025 11:28:53 -0400 Message-ID: <20250416152854.15269-2-cel@kernel.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250416152854.15269-1-cel@kernel.org> References: <20250416152854.15269-1-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, replace the fixed-size rq_bvec[] array in struct svc_rqst with a chunk of dynamically-allocated memory. 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 7500 bytes. Signed-off-by: Chuck Lever --- include/linux/sunrpc/svc.h | 2 +- net/sunrpc/svc.c | 6 ++++++ net/sunrpc/svcsock.c | 7 +++---- 3 files changed, 10 insertions(+), 5 deletions(-) diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h index 74658cca0f38..225c385085c3 100644 --- a/include/linux/sunrpc/svc.h +++ b/include/linux/sunrpc/svc.h @@ -195,7 +195,7 @@ struct svc_rqst { struct folio_batch rq_fbatch; struct kvec rq_vec[RPCSVC_MAXPAGES]; /* generally useful.. */ - 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 e7f9c295d13c..db29819716b8 100644 --- a/net/sunrpc/svc.c +++ b/net/sunrpc/svc.c @@ -673,6 +673,7 @@ static void svc_rqst_free(struct svc_rqst *rqstp) { folio_batch_release(&rqstp->rq_fbatch); + kfree(rqstp->rq_bvec); svc_release_buffer(rqstp); if (rqstp->rq_scratch_page) put_page(rqstp->rq_scratch_page); @@ -711,6 +712,11 @@ svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool, int node) if (!svc_init_buffer(rqstp, serv->sv_max_mesg, node)) goto out_enomem; + rqstp->rq_bvec = kcalloc_node(RPCSVC_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..671640933f18 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, RPCSVC_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, RPCSVC_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