From owner-dev-commits-src-branches@freebsd.org Tue Jul 13 01:54:51 2021 Return-Path: Delivered-To: dev-commits-src-branches@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 8B31364DA84; Tue, 13 Jul 2021 01:54:51 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4GP3bv3Hbvz3Mv1; Tue, 13 Jul 2021 01:54:51 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 539F719D0A; Tue, 13 Jul 2021 01:54:51 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 16D1spxm023914; Tue, 13 Jul 2021 01:54:51 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 16D1spHT023913; Tue, 13 Jul 2021 01:54:51 GMT (envelope-from git) Date: Tue, 13 Jul 2021 01:54:51 GMT Message-Id: <202107130154.16D1spHT023913@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Alexander Motin Subject: git: a469b89bf206 - stable/13 - nvme(4): Report NPWA before NPWG as stripesize. MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: mav X-Git-Repository: src X-Git-Refname: refs/heads/stable/13 X-Git-Reftype: branch X-Git-Commit: a469b89bf206731430f26e975d120c4485b71e23 Auto-Submitted: auto-generated X-BeenThere: dev-commits-src-branches@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Commits to the stable branches of the FreeBSD src repository List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 13 Jul 2021 01:54:51 -0000 The branch stable/13 has been updated by mav: URL: https://cgit.FreeBSD.org/src/commit/?id=a469b89bf206731430f26e975d120c4485b71e23 commit a469b89bf206731430f26e975d120c4485b71e23 Author: Alexander Motin AuthorDate: 2021-07-06 02:19:48 +0000 Commit: Alexander Motin CommitDate: 2021-07-13 01:54:44 +0000 nvme(4): Report NPWA before NPWG as stripesize. New Samsung 980 SSDs report Namespace Preferred Write Alignment of 8 (4KB) and Namespace Preferred Write Granularity of 32 (16KB). My quick tests show that 16KB is a minimal sequential write size when the SSD reaches peak IOPS, so writing much less is very slow. But writing slightly less or slightly more does not change much, so it seems not so much a size granularity as minimum I/O size. Thinking about different stripesize consumers: - Partition alignment should be based on NPWA by definition. - ZFS ashift in part of forcing alignment of all I/Os should also be based on NPWA. In part of forcing size granularity, if really needed, it may be set to NPWG, but too big value can make ZFS too space-inefficient, and the 16KB is actually the biggest supported value there now. - ZFS recordsize/volblocksize could potentially be tuned up toward NPWG to work as I/O size granularity, but enabled compression makes it too fuzzy. And those are normally user-configurable things. - ZFS I/O aggregation code could definitely use Optimal Write Size value and may be NPWG, but we don't have fields in GEOM now to report the minimal and optimal I/O sizes, and even maximal is not reported outside GEOM DISK to be used by ZFS. MFC after: 1 week (cherry picked from commit e3bcd07d834def94dcf570ac7350ca2c454ebf10) --- sys/dev/nvme/nvme_ns.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/sys/dev/nvme/nvme_ns.c b/sys/dev/nvme/nvme_ns.c index 82ab48efa826..8f97b08b88f4 100644 --- a/sys/dev/nvme/nvme_ns.c +++ b/sys/dev/nvme/nvme_ns.c @@ -231,10 +231,15 @@ nvme_ns_get_data(struct nvme_namespace *ns) uint32_t nvme_ns_get_stripesize(struct nvme_namespace *ns) { + uint32_t ss; if (((ns->data.nsfeat >> NVME_NS_DATA_NSFEAT_NPVALID_SHIFT) & - NVME_NS_DATA_NSFEAT_NPVALID_MASK) != 0 && ns->data.npwg != 0) { - return ((ns->data.npwg + 1) * nvme_ns_get_sector_size(ns)); + NVME_NS_DATA_NSFEAT_NPVALID_MASK) != 0) { + ss = nvme_ns_get_sector_size(ns); + if (ns->data.npwa != 0) + return ((ns->data.npwa + 1) * ss); + else if (ns->data.npwg != 0) + return ((ns->data.npwg + 1) * ss); } return (ns->boundary); }