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 8C5072080DB for ; Wed, 16 Apr 2025 15:28:59 +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=1744817339; cv=none; b=T1y4r3EOZ/V1tREQzeHJG0Ca1h0YwBJZH8LEGb09LjtA7EmE7GQgM+TJSEZT26WBHs7GvgvYavN/l9/Wcdt1udsuOcu835WfqcudR8ABDy/GfAD9YuqXiolfTxaN0BgAJHg6saAWU9A9AbCC0LhEpKQWMciMkVlp4sDKwIYmr2w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744817339; c=relaxed/simple; bh=cCJQXTL4g18PQ9Q7cI4mJ71WzF5rruMcQyqcExY9Y50=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=p+fxOFXno2Po0KG5vpU7Z/UyE258Z0YJ28DqoFVQgNkz6UgtCT9p60DZ8w+cManbAu5DUkJUSglc/s/KL5Pk2dYQOXdaWALxf8GPsE/etqbzMtS19c4Vs/zwUBnT0FQ8vfoBX9B/FBCfmaWz+OOk+7fuvjXS6Gx4ZkeSUaIACgo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NGJgFp3l; 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="NGJgFp3l" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4E353C4CEF1; Wed, 16 Apr 2025 15:28:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1744817339; bh=cCJQXTL4g18PQ9Q7cI4mJ71WzF5rruMcQyqcExY9Y50=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NGJgFp3lMEeOO+fYonnh0qxVh7gWhq3uZJGzfiZIkWLxfmLPwbhh0k5wWL8f+306y bLDl5W5/MvXmfLYJ9Oi35TjL5NX2PggjMwhptJNxUDIXeJ3XVwtD4dBW+osuSXzlfV 2KYPUIt2XZg/Fyl6EatRjnGYHLTwar9WiWapK8ctogToPw4ur+wuouAG1yO5dX69Wg DiokDQzin2MHm5eGAp7FS6CUE7A5JUreqMhVW25NNQLhJVOasWNfH3iKUas1CYQNiH oqMpBfiqfbFbrkupC7iodl9qR5w8BKqL9GeLgcnpeAE+/eKo4faCBNc4CdpNg/TZcK /3NuG8o4/+8lQ== From: cel@kernel.org To: NeilBrown , Jeff Layton , Olga Kornievskaia , Dai Ngo , Tom Talpey Cc: , Chuck Lever Subject: [RFC PATCH 2/2] sunrpc: Replace the rq_vec array with dynamically-allocated memory Date: Wed, 16 Apr 2025 11:28:54 -0400 Message-ID: <20250416152854.15269-3-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_vec[] 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_vec[] array is 4144 bytes. Replacing it with a single pointer reduces the size of struct svc_rqst to about 3300 bytes. Signed-off-by: Chuck Lever --- fs/nfsd/nfs4proc.c | 2 +- fs/nfsd/vfs.c | 2 +- include/linux/sunrpc/svc.h | 2 +- net/sunrpc/svc.c | 8 +++++++- 4 files changed, 10 insertions(+), 4 deletions(-) diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index b397246dae7b..79ee58202396 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -1228,7 +1228,7 @@ 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)); + /* 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..ae0901d6db1a 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 > RPCSVC_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 225c385085c3..13b6d0753bc0 100644 --- a/include/linux/sunrpc/svc.h +++ b/include/linux/sunrpc/svc.h @@ -194,7 +194,7 @@ 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; __be32 rq_xid; /* transmission id */ diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c index db29819716b8..8d28aeb74e1b 100644 --- a/net/sunrpc/svc.c +++ b/net/sunrpc/svc.c @@ -674,6 +674,7 @@ 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) put_page(rqstp->rq_scratch_page); @@ -712,6 +713,11 @@ 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_vec = kcalloc_node(RPCSVC_MAXPAGES, sizeof(struct kvec), + GFP_KERNEL, node); + if (!rqstp->rq_vec) + goto out_enomem; + rqstp->rq_bvec = kcalloc_node(RPCSVC_MAXPAGES, sizeof(struct bio_vec), GFP_KERNEL, node); if (!rqstp->rq_bvec) @@ -1754,7 +1760,7 @@ unsigned int svc_fill_write_vector(struct svc_rqst *rqstp, ++pages; } - WARN_ON_ONCE(i > ARRAY_SIZE(rqstp->rq_vec)); + WARN_ON_ONCE(i > RPCSVC_MAXPAGES); return i; } EXPORT_SYMBOL_GPL(svc_fill_write_vector); -- 2.49.0