From owner-svn-src-all@freebsd.org Sun Nov 17 22:44:39 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 EA53E1AD6DA; Sun, 17 Nov 2019 22:44:39 +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 47GRwl46Dxz4clf; Sun, 17 Nov 2019 22:44:39 +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 662EE20C1C; Sun, 17 Nov 2019 22:44:39 +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 xAHMidcY042916; Sun, 17 Nov 2019 22:44:39 GMT (envelope-from alc@FreeBSD.org) Received: (from alc@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id xAHMid7U042915; Sun, 17 Nov 2019 22:44:39 GMT (envelope-from alc@FreeBSD.org) Message-Id: <201911172244.xAHMid7U042915@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: alc set sender to alc@FreeBSD.org using -f From: Alan Cox Date: Sun, 17 Nov 2019 22:44:39 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-12@freebsd.org Subject: svn commit: r354799 - stable/12/sys/arm64/arm64 X-SVN-Group: stable-12 X-SVN-Commit-Author: alc X-SVN-Commit-Paths: stable/12/sys/arm64/arm64 X-SVN-Commit-Revision: 354799 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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: Sun, 17 Nov 2019 22:44:40 -0000 Author: alc Date: Sun Nov 17 22:44:38 2019 New Revision: 354799 URL: https://svnweb.freebsd.org/changeset/base/354799 Log: MFC r352847,352930,354585 Eliminate redundant calls to critical_enter() and critical_exit() from pmap_update_entry(). It suffices that interrupts are blocked. In short, pmap_enter_quick_locked("user space", ..., VM_PROT_READ) doesn't work. More precisely, it doesn't set ATTR_AP(ATTR_AP_USER) in the page table entry, so any attempt to read from the mapped page by user space generates a page fault. This problem has gone unnoticed because the page fault handler, vm_fault(), will ultimately call pmap_enter(), which replaces the non-working page table entry with one that has ATTR_AP(ATTR_AP_USER) set. This change reduces the number of page faults during a "buildworld" by about 19.4%. Eliminate a redundant pmap_load() from pmap_remove_pages(). There is no reason why the pmap_invalidate_all() in pmap_remove_pages() must be performed before the final PV list lock release. Move it past the lock release. Eliminate a stale comment from pmap_page_test_mappings(). We implemented a modified bit in r350004. Modified: stable/12/sys/arm64/arm64/pmap.c Directory Properties: stable/12/ (props changed) Modified: stable/12/sys/arm64/arm64/pmap.c ============================================================================== --- stable/12/sys/arm64/arm64/pmap.c Sun Nov 17 20:56:25 2019 (r354798) +++ stable/12/sys/arm64/arm64/pmap.c Sun Nov 17 22:44:38 2019 (r354799) @@ -3019,7 +3019,6 @@ pmap_update_entry(pmap_t pmap, pd_entry_t *pte, pd_ent * as they may make use of an address we are about to invalidate. */ intr = intr_disable(); - critical_enter(); /* Clear the old mapping */ pmap_clear(pte); @@ -3029,7 +3028,6 @@ pmap_update_entry(pmap_t pmap, pd_entry_t *pte, pd_ent pmap_store(pte, newpte); dsb(ishst); - critical_exit(); intr_restore(intr); } @@ -3763,8 +3761,8 @@ pmap_enter_quick_locked(pmap_t pmap, vm_offset_t va, v ATTR_AP(ATTR_AP_RO) | L3_PAGE; if ((prot & VM_PROT_EXECUTE) == 0 || m->md.pv_memattr == DEVICE_MEMORY) l3_val |= ATTR_XN; - else if (va < VM_MAXUSER_ADDRESS) - l3_val |= ATTR_PXN; + if (va < VM_MAXUSER_ADDRESS) + l3_val |= ATTR_AP(ATTR_AP_USER) | ATTR_PXN; /* * Now validate mapping with RO protection @@ -4330,7 +4328,6 @@ pmap_remove_pages(pmap_t pmap) L2_BLOCK, ("Attempting to remove an invalid " "block: %lx", tpte)); - tpte = pmap_load(pte); break; case 2: pte = pmap_l2_to_l3(pde, pv->pv_va); @@ -4448,17 +4445,15 @@ pmap_remove_pages(pmap_t pmap) free_pv_chunk(pc); } } - pmap_invalidate_all(pmap); if (lock != NULL) rw_wunlock(lock); + pmap_invalidate_all(pmap); PMAP_UNLOCK(pmap); vm_page_free_pages_toq(&free, true); } /* - * This is used to check if a page has been accessed or modified. As we - * don't have a bit to see if it has been modified we have to assume it - * has been if the page is read/write. + * This is used to check if a page has been accessed or modified. */ static boolean_t pmap_page_test_mappings(vm_page_t m, boolean_t accessed, boolean_t modified)