From nobody Thu Oct 28 19:02:11 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 082671826240; Thu, 28 Oct 2021 19:02:12 +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 4HgFKv5j0yz4sCk; Thu, 28 Oct 2021 19:02:11 +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 8DD641016; Thu, 28 Oct 2021 19:02:11 +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 19SJ2BKP095345; Thu, 28 Oct 2021 19:02:11 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 19SJ2BRQ095344; Thu, 28 Oct 2021 19:02:11 GMT (envelope-from git) Date: Thu, 28 Oct 2021 19:02:11 GMT Message-Id: <202110281902.19SJ2BRQ095344@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Konstantin Belousov Subject: git: 0b3bc7288984 - main - amd64 pmap: adjust the empty pmap optimization in pmap_remove() 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: kib X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 0b3bc7288984c17da00d9f8c29f116d56bf44d35 Auto-Submitted: auto-generated X-ThisMailContainsUnwantedMimeParts: N The branch main has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=0b3bc7288984c17da00d9f8c29f116d56bf44d35 commit 0b3bc7288984c17da00d9f8c29f116d56bf44d35 Author: Konstantin Belousov AuthorDate: 2021-10-20 20:30:34 +0000 Commit: Konstantin Belousov CommitDate: 2021-10-28 19:01:58 +0000 amd64 pmap: adjust the empty pmap optimization in pmap_remove() to match the added accounting of the top-level page table pages. Reviewed by: markj Tested by: markj Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D32569 --- sys/amd64/amd64/pmap.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c index 1c4e8b3354fc..8526cc3031d2 100644 --- a/sys/amd64/amd64/pmap.c +++ b/sys/amd64/amd64/pmap.c @@ -6278,9 +6278,14 @@ pmap_remove(pmap_t pmap, vm_offset_t sva, vm_offset_t eva) PG_V = pmap_valid_bit(pmap); /* + * If there are no resident pages besides the top level page + * table page(s), there is nothing to do. Kernel pmap always + * accounts whole preloaded area as resident, which makes its + * resident count > 2. * Perform an unsynchronized read. This is, however, safe. */ - if (pmap->pm_stats.resident_count == 0) + if (pmap->pm_stats.resident_count <= 1 + (pmap->pm_pmltopu != NULL ? + 1 : 0)) return; anyvalid = 0;