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 3A3311DF991 for ; Sat, 19 Apr 2025 17:28:25 +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=1745083705; cv=none; b=OaQpuC+CScnIdxzukaJAbO/iHQo2p97eQua+kbd04gG06j9TLVE/Fnm7fWf7yX/rB+ppJxm93a3lCMDi5WAIQUYmG1cHCDMSuvahviKbYTI4qbKNY12Box34dmn0PmOZrE+UmbSjAO2lP/M+Vtf2o6+uB2uzLTlklJSegqwV7Z8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745083705; c=relaxed/simple; bh=w2ShGO9ROIkEGlEzAtRx2bKgV2rgvqHhzRiDIS44PCk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=DR/QxYULEiz/GN9Jforh3Qfbq/1HY4yvPg4Ptpcx3hL32A1jkHG28UiLhQZUgvASTb0jNcVMdZGYVAn8ihOEo0lZR3Sg0UMH4qnehiwhvD/As0BNI9yX3zRNOBDiirDLyE9CITEMWFVXrjzWcg656vNT5BxTX9E4RRCTsF7jR0E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=fFK/GjTA; 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="fFK/GjTA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 65D0DC4CEEE; Sat, 19 Apr 2025 17:28:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1745083705; bh=w2ShGO9ROIkEGlEzAtRx2bKgV2rgvqHhzRiDIS44PCk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fFK/GjTACDI8zZTYmaTg40oyo8Fqai6w4Hv7zbUBkm+pP106XYv7EfXg1hQoi7vjN k+l0Ip9nkonJvW8tzSQlo5H0q6OjpiYpR3WhCyaVXyd4FctiSJwTWmdcrZoFbbAHey c/7ekvkvwD1xaktUmhRM9/9kaJ495iIBNY+MCB81zYtKdNXytBkiWF5MZY+MirXwmQ QUr67+FOZ+clK5DG+c5uFev6+XctHqlwr+oVGazftRkPxyk1q7YlzPtHdJb/21sXl1 0zwAKKpSi9ve2Y1puiqmFk3/QamweCScpr11nj6Iuz7SZu/dhGYObJVnrhTS0ABc/Z BILxfd7hU8geA== From: cel@kernel.org To: NeilBrown , Jeff Layton , Olga Kornievskaia , Dai Ngo , Tom Talpey Cc: , Chuck Lever Subject: [PATCH v2 04/10] sunrpc: Replace the rq_vec array with dynamically-allocated memory Date: Sat, 19 Apr 2025 13:28:12 -0400 Message-ID: <20250419172818.6945-5-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_vec[] array in struct svc_rqst with a chunk of dynamically-allocated memory. The rq_vec array is sized assuming request processing will need at most one kvec per page in a maximum-sized RPC message. On a system with 8-byte pointers and 4KB pages, pahole reports that the rq_vec[] array is 4144 bytes. Replacing it with a single pointer reduces the size of struct svc_rqst to about 5400 bytes. Signed-off-by: Chuck Lever --- fs/nfsd/nfs4proc.c | 1 - fs/nfsd/vfs.c | 2 +- include/linux/sunrpc/svc.h | 2 +- net/sunrpc/svc.c | 8 +++++++- 4 files changed, 9 insertions(+), 4 deletions(-) diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index b397246dae7b..d1be58b557d1 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -1228,7 +1228,6 @@ nfsd4_write(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, write->wr_how_written = write->wr_stable_how; nvecs = svc_fill_write_vector(rqstp, &write->wr_payload); - WARN_ON_ONCE(nvecs > ARRAY_SIZE(rqstp->rq_vec)); status = nfsd_vfs_write(rqstp, &cstate->current_fh, nf, write->wr_offset, rqstp->rq_vec, nvecs, &cnt, diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 9abdc4b75813..4eaac3aa7e15 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -1094,7 +1094,7 @@ __be32 nfsd_iter_read(struct svc_rqst *rqstp, struct svc_fh *fhp, ++v; base = 0; } - WARN_ON_ONCE(v > ARRAY_SIZE(rqstp->rq_vec)); + WARN_ON_ONCE(v > rqstp->rq_maxpages); trace_nfsd_read_vector(rqstp, fhp, offset, *count); iov_iter_kvec(&iter, ITER_DEST, rqstp->rq_vec, v, *count); diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h index 96ac12dbb04d..72d016772711 100644 --- a/include/linux/sunrpc/svc.h +++ b/include/linux/sunrpc/svc.h @@ -207,7 +207,7 @@ struct svc_rqst { struct page * *rq_page_end; /* one past the last page */ struct folio_batch rq_fbatch; - struct kvec rq_vec[RPCSVC_MAXPAGES]; /* generally useful.. */ + struct kvec *rq_vec; struct bio_vec rq_bvec[RPCSVC_MAXPAGES]; __be32 rq_xid; /* transmission id */ diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c index 682e11c9be36..5808d4b97547 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_vec); svc_release_buffer(rqstp); if (rqstp->rq_scratch_page) put_page(rqstp->rq_scratch_page); @@ -713,6 +714,11 @@ svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool, int node) if (!svc_init_buffer(rqstp, serv, node)) goto out_enomem; + rqstp->rq_vec = kcalloc_node(rqstp->rq_maxpages, sizeof(struct kvec), + GFP_KERNEL, node); + if (!rqstp->rq_vec) + goto out_enomem; + rqstp->rq_err = -EAGAIN; /* No error yet */ serv->sv_nrthreads += 1; @@ -1750,7 +1756,7 @@ unsigned int svc_fill_write_vector(struct svc_rqst *rqstp, ++pages; } - WARN_ON_ONCE(i > ARRAY_SIZE(rqstp->rq_vec)); + WARN_ON_ONCE(i > rqstp->rq_maxpages); return i; } EXPORT_SYMBOL_GPL(svc_fill_write_vector); -- 2.49.0