Date: Mon, 14 Jan 2019 07:25:44 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-11@freebsd.org Subject: svn commit: r343016 - in stable/11: lib/libc/sys sys/vm Message-ID: <201901140725.x0E7Pine064851@repo.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: kib Date: Mon Jan 14 07:25:44 2019 New Revision: 343016 URL: https://svnweb.freebsd.org/changeset/base/343016 Log: MFC r342853: Add a tunable which changes mincore(2) algorithm to only report data from the local mapping. Modified: stable/11/lib/libc/sys/mincore.2 stable/11/sys/vm/vm_mmap.c Directory Properties: stable/11/ (props changed) Modified: stable/11/lib/libc/sys/mincore.2 ============================================================================== --- stable/11/lib/libc/sys/mincore.2 Mon Jan 14 07:24:49 2019 (r343015) +++ stable/11/lib/libc/sys/mincore.2 Mon Jan 14 07:25:44 2019 (r343016) @@ -28,7 +28,7 @@ .\" @(#)mincore.2 8.1 (Berkeley) 6/9/93 .\" $FreeBSD$ .\" -.Dd June 1, 2018 +.Dd January 7, 2019 .Dt MINCORE 2 .Os .Sh NAME @@ -47,7 +47,8 @@ system call determines whether each of the pages in th .Fa addr and continuing for .Fa len -bytes is resident. +bytes is resident or mapped, depending on the value of sysctl +.Va vm.mincore_mapped . .\"The beginning address, .\".Fa addr , .\"is first rounded down to a multiple of the page size (see @@ -85,6 +86,18 @@ The only way to ensure that a page is resident is to l with the .Xr mlock 2 system call. +.Pp +If the +.Va vm.mincore_mapped +sysctl is set to a non-zero value (default), only the current process' +mappings of the pages in the specified virtual address range are examined. +This does not preclude the system from returning +.Dv MINCORE_REFERENCED_OTHER +and +.Dv MINCORE_MODIFIED_OTHER +statuses. +Otherwise, if the sysctl value is zero, all resident pages backing the +specified address range are examined, regardless of the mapping state. .Sh RETURN VALUES .Rv -std mincore .Sh ERRORS Modified: stable/11/sys/vm/vm_mmap.c ============================================================================== --- stable/11/sys/vm/vm_mmap.c Mon Jan 14 07:24:49 2019 (r343015) +++ stable/11/sys/vm/vm_mmap.c Mon Jan 14 07:25:44 2019 (r343016) @@ -96,6 +96,9 @@ __FBSDID("$FreeBSD$"); int old_mlock = 0; SYSCTL_INT(_vm, OID_AUTO, old_mlock, CTLFLAG_RWTUN, &old_mlock, 0, "Do not apply RLIMIT_MEMLOCK on mlockall"); +static int mincore_mapped = 1; +SYSCTL_INT(_vm, OID_AUTO, mincore_mapped, CTLFLAG_RWTUN, &mincore_mapped, 0, + "mincore reports mappings, not residency"); #ifdef MAP_32BIT #define MAP_32BIT_MAX_ADDR ((vm_offset_t)1 << 31) @@ -814,7 +817,16 @@ RestartScan: retry: m = NULL; mincoreinfo = pmap_mincore(pmap, addr, &locked_pa); - if (locked_pa != 0) { + if (mincore_mapped) { + /* + * We only care about this pmap's + * mapping of the page, if any. + */ + if (locked_pa != 0) { + vm_page_unlock(PHYS_TO_VM_PAGE( + locked_pa)); + } + } else if (locked_pa != 0) { /* * The page is mapped by this process but not * both accessed and modified. It is also
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201901140725.x0E7Pine064851>