From nobody Thu Nov 04 01:08:00 2021 X-Original-To: dev-commits-src-branches@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 5C14B184A79B; Thu, 4 Nov 2021 01:08:01 +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 4Hl59D6P7Vz4jZB; Thu, 4 Nov 2021 01:08:00 +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 AD6E822EC2; Thu, 4 Nov 2021 01:08:00 +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 1A4180UM007754; Thu, 4 Nov 2021 01:08:00 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 1A418074007753; Thu, 4 Nov 2021 01:08:00 GMT (envelope-from git) Date: Thu, 4 Nov 2021 01:08:00 GMT Message-Id: <202111040108.1A418074007753@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Konstantin Belousov Subject: git: 077d3c4c467e - stable/13 - amd64 pmap: adjust the empty pmap optimization in pmap_remove() List-Id: Commits to the stable branches of the FreeBSD src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-branches List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-dev-commits-src-branches@freebsd.org X-BeenThere: dev-commits-src-branches@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/stable/13 X-Git-Reftype: branch X-Git-Commit: 077d3c4c467e5e27f88b8d70864000f3eb0dab3c Auto-Submitted: auto-generated X-ThisMailContainsUnwantedMimeParts: N The branch stable/13 has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=077d3c4c467e5e27f88b8d70864000f3eb0dab3c commit 077d3c4c467e5e27f88b8d70864000f3eb0dab3c Author: Konstantin Belousov AuthorDate: 2021-10-20 20:30:34 +0000 Commit: Konstantin Belousov CommitDate: 2021-11-04 00:56:39 +0000 amd64 pmap: adjust the empty pmap optimization in pmap_remove() (cherry picked from commit 0b3bc7288984c17da00d9f8c29f116d56bf44d35) --- 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 c759ff840a24..524b40ed2fee 100644 --- a/sys/amd64/amd64/pmap.c +++ b/sys/amd64/amd64/pmap.c @@ -6160,9 +6160,14 @@ 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;