From owner-svn-src-all@freebsd.org Tue Jul 16 03:09:04 2019 Return-Path: Delivered-To: svn-src-all@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 87034A432F; Tue, 16 Jul 2019 03:09:04 +0000 (UTC) (envelope-from alc@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) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 68A238D8AF; Tue, 16 Jul 2019 03:09:04 +0000 (UTC) (envelope-from alc@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 5C51027716; Tue, 16 Jul 2019 03:09:04 +0000 (UTC) (envelope-from alc@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id x6G394ZR059295; Tue, 16 Jul 2019 03:09:04 GMT (envelope-from alc@FreeBSD.org) Received: (from alc@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x6G39467059294; Tue, 16 Jul 2019 03:09:04 GMT (envelope-from alc@FreeBSD.org) Message-Id: <201907160309.x6G39467059294@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: alc set sender to alc@FreeBSD.org using -f From: Alan Cox Date: Tue, 16 Jul 2019 03:09:04 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r350021 - head/sys/i386/i386 X-SVN-Group: head X-SVN-Commit-Author: alc X-SVN-Commit-Paths: head/sys/i386/i386 X-SVN-Commit-Revision: 350021 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 68A238D8AF X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-2.95 / 15.00]; local_wl_from(0.00)[FreeBSD.org]; NEURAL_HAM_MEDIUM(-1.00)[-0.996,0]; NEURAL_HAM_SHORT(-0.95)[-0.950,0]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; ASN(0.00)[asn:11403, ipnet:2610:1c1:1::/48, country:US] X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 16 Jul 2019 03:09:04 -0000 Author: alc Date: Tue Jul 16 03:09:03 2019 New Revision: 350021 URL: https://svnweb.freebsd.org/changeset/base/350021 Log: Revert r349973. Upon further reflection, I realized that the comment deleted by r349973 is still valid on i386. Restore it. Discussed with: markj Modified: head/sys/i386/i386/pmap.c Modified: head/sys/i386/i386/pmap.c ============================================================================== --- head/sys/i386/i386/pmap.c Mon Jul 15 23:43:38 2019 (r350020) +++ head/sys/i386/i386/pmap.c Tue Jul 16 03:09:03 2019 (r350021) @@ -5096,6 +5096,13 @@ __CONCAT(PMTYPE, ts_referenced)(vm_page_t m) * reference bit will result in clearing that bit. * This function is designed to avoid the selection of * the same 4KB page for every 2- or 4MB page mapping. + * + * On demotion, a mapping that hasn't been referenced + * is simply destroyed. To avoid the possibility of a + * subsequent page fault on a demoted wired mapping, + * always leave its reference bit set. Moreover, + * since the superpage is wired, the current state of + * its reference bit won't affect page replacement. */ if ((((pa >> PAGE_SHIFT) ^ (pv->pv_va >> PDRSHIFT) ^ (uintptr_t)pmap) & (NPTEPG - 1)) == 0 &&