From nobody Thu Oct 14 14:45:36 2021 X-Original-To: dev-commits-src-main@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 411201812F79; Thu, 14 Oct 2021 14:45:37 +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 4HVXJK15Jqz4X9g; Thu, 14 Oct 2021 14:45:37 +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 04B521541C; Thu, 14 Oct 2021 14:45:37 +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 19EEjamK027334; Thu, 14 Oct 2021 14:45:36 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 19EEja1F027333; Thu, 14 Oct 2021 14:45:36 GMT (envelope-from git) Date: Thu, 14 Oct 2021 14:45:36 GMT Message-Id: <202110141445.19EEja1F027333@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Warner Losh Subject: git: 2ec165e3f065 - main - nvme: Reduce traffic to the doorbell register List-Id: Commit messages for the main branch of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-main List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-dev-commits-src-main@freebsd.org X-BeenThere: dev-commits-src-main@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: imp X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 2ec165e3f065217ae8d54a2a8235fe1f219805ea Auto-Submitted: auto-generated X-ThisMailContainsUnwantedMimeParts: N The branch main has been updated by imp: URL: https://cgit.FreeBSD.org/src/commit/?id=2ec165e3f065217ae8d54a2a8235fe1f219805ea commit 2ec165e3f065217ae8d54a2a8235fe1f219805ea Author: Warner Losh AuthorDate: 2021-10-14 14:44:37 +0000 Commit: Warner Losh CommitDate: 2021-10-14 14:44:37 +0000 nvme: Reduce traffic to the doorbell register Reduce traffic to doorbell register when processing multiple completion events at once. Only write it at the end of the loop after we've processed everything (assuming we found at least one completion, even if that completion wasn't valid). Sponsored by: Netflix Reviewed by: mav Differential Revision: https://reviews.freebsd.org/D32470 --- sys/dev/nvme/nvme_qpair.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/sys/dev/nvme/nvme_qpair.c b/sys/dev/nvme/nvme_qpair.c index 6669eeee6613..54718492ff09 100644 --- a/sys/dev/nvme/nvme_qpair.c +++ b/sys/dev/nvme/nvme_qpair.c @@ -629,10 +629,10 @@ nvme_qpair_process_completions(struct nvme_qpair *qpair) else tr = NULL; + done++; if (tr != NULL) { nvme_qpair_complete_tracker(tr, &cpl, ERROR_PRINT_ALL); qpair->sq_head = cpl.sqhd; - done++; } else if (!in_panic) { /* * A missing tracker is normally an error. However, a @@ -664,10 +664,13 @@ nvme_qpair_process_completions(struct nvme_qpair *qpair) atomic_store_rel_int(&qpair->cq_head, 0); /* 2 */ qpair->phase = !qpair->phase; /* 3 */ } + } + if (done != 0) { bus_space_write_4(qpair->ctrlr->bus_tag, qpair->ctrlr->bus_handle, qpair->cq_hdbl_off, qpair->cq_head); } + return (done != 0); }