From owner-svn-src-all@freebsd.org Mon Nov 5 20:00:37 2018 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 4FA58110A59A; Mon, 5 Nov 2018 20:00:37 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id D206970766; Mon, 5 Nov 2018 20:00:36 +0000 (UTC) (envelope-from jhb@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 B309E1C234; Mon, 5 Nov 2018 20:00:36 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id wA5K0aKH093002; Mon, 5 Nov 2018 20:00:36 GMT (envelope-from jhb@FreeBSD.org) Received: (from jhb@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id wA5K0aKq093001; Mon, 5 Nov 2018 20:00:36 GMT (envelope-from jhb@FreeBSD.org) Message-Id: <201811052000.wA5K0aKq093001@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: jhb set sender to jhb@FreeBSD.org using -f From: John Baldwin Date: Mon, 5 Nov 2018 20:00:36 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r340159 - head/sys/riscv/riscv X-SVN-Group: head X-SVN-Commit-Author: jhb X-SVN-Commit-Paths: head/sys/riscv/riscv X-SVN-Commit-Revision: 340159 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: D206970766 X-Spamd-Result: default: False [-1.49 / 200.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-0.76)[-0.756,0]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[3]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_GOOD(-0.10)[text/plain]; TO_DN_NONE(0.00)[]; HAS_XAW(0.00)[]; R_SPF_SOFTFAIL(0.00)[~all]; DMARC_NA(0.00)[FreeBSD.org]; RCVD_COUNT_THREE(0.00)[4]; MX_GOOD(-0.01)[cached: mx1.FreeBSD.org]; NEURAL_HAM_SHORT(-0.62)[-0.620,0]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; RCVD_TLS_LAST(0.00)[] X-Rspamd-Server: mx1.freebsd.org 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: Mon, 05 Nov 2018 20:00:37 -0000 Author: jhb Date: Mon Nov 5 20:00:36 2018 New Revision: 340159 URL: https://svnweb.freebsd.org/changeset/base/340159 Log: Rework setting PTE_D for kernel mappings. Rather than unconditionally setting PTE_D for all writeable kernel mappings, set PTE_D for writable mappings of unmanaged pages (whether user or kernel). This matches what amd64 does and also matches what the RISC-V spec suggests (preset the A and D bits on mappings where the OS doesn't care about the state). Suggested by: alc Reviewed by: alc, markj Sponsored by: DARPA Modified: head/sys/riscv/riscv/pmap.c Modified: head/sys/riscv/riscv/pmap.c ============================================================================== --- head/sys/riscv/riscv/pmap.c Mon Nov 5 19:51:16 2018 (r340158) +++ head/sys/riscv/riscv/pmap.c Mon Nov 5 20:00:36 2018 (r340159) @@ -2098,13 +2098,20 @@ pmap_enter(pmap_t pmap, vm_offset_t va, vm_page_t m, v new_l3 |= PTE_W; if ((va >> 63) == 0) new_l3 |= PTE_U; - else if (prot & VM_PROT_WRITE) - new_l3 |= PTE_D; new_l3 |= (pn << PTE_PPN0_S); if ((flags & PMAP_ENTER_WIRED) != 0) new_l3 |= PTE_SW_WIRED; - if ((m->oflags & VPO_UNMANAGED) == 0) + + /* + * Set modified bit gratuitously for writeable mappings if + * the page is unmanaged. We do not want to take a fault + * to do the dirty bit accounting for these mappings. + */ + if ((m->oflags & VPO_UNMANAGED) != 0) { + if (prot & VM_PROT_WRITE) + new_l3 |= PTE_D; + } else new_l3 |= PTE_SW_MANAGED; CTR2(KTR_PMAP, "pmap_enter: %.16lx -> %.16lx", va, pa);