On Sat, Jan 12, 2019 at 02:01:13PM +0100, Jeremie Courreges-Anglas wrote:
>
> So mongodb didn't show up when guenther@ looked for mincore(2) users in
> ports, because the search was done over i386 .o, but mongodb is only for
> amd64.
>
> Here's a diff to unbreak it. There's a "feature check" function
> blockCheckSupported() which now returns false, if code ends up querying
> the presence of pages in memory with blockInMemory() or pagesInMemory()
> the answer will also be false. I think those defaults are consistent
> with the choices made in
> src/mongo/db/storage/mmap_v1/record_access_tracker.cpp
> See "if (!_blockSupported)".
>
> --8<--
> bool RecordAccessTracker::checkAccessedAndMark(const void* record) {
> const size_t page = reinterpret_cast<size_t>(record) >> 12;
> const size_t region = page >> 6;
> const size_t offset = page & 0x3f;
>
> // This is like the "L1 cache". If we're a miss then we fall through and
> check the
> // "L2 cache". If we're still a miss, then we defer to a system-specific
> system
> // call (or give up and return false if deferring to the system call is
> not enabled).
> if (PointerTable::seen(PointerTable::getData(),
> reinterpret_cast<size_t>(record))) {
> return true;
> }
>
> // We were a miss in the PointerTable. See if we can find 'record' in the
> Rolling table.
> if (_rollingTable[bigHash(region)].access(region, offset, false)) {
> return true;
> }
>
> if (!_blockSupported) {
> // This means we don't fall back to a system call. Instead we assume
> things aren't
> // in memory. This could mean that we yield too much, but this is
> much better
> // than the alternative of not yielding through a page fault.
> return false;
> }
>
> return ProcessInfo::blockInMemory(const_cast<void*>(record));
> }
> -->8--
>
> mongodb will now print a warning on startup:
> --8<--
> 2019-01-12T13:56:00.082+0100 I CONTROL [initandlisten] ** NOTE: your
> operating system version does not support the method that MongoDB
> 2019-01-12T13:56:00.082+0100 I CONTROL [initandlisten] ** uses to
> detect impending page faults.
> 2019-01-12T13:56:00.082+0100 I CONTROL [initandlisten] ** This may
> result in slower performance for certain use cases
> -->8--
>
> On a new install I had to tweak the rcscript so that the default log
> file can be opened and written to. I can commit that part separately.
No, that should be created by the package itseld (@sample).
>
> Index: Makefile
> ===================================================================
> RCS file: /cvs/ports/databases/mongodb/Makefile,v
> retrieving revision 1.33
> diff -u -p -r1.33 Makefile
> --- Makefile 13 Dec 2018 19:53:23 -0000 1.33
> +++ Makefile 12 Jan 2019 12:59:25 -0000
> @@ -12,7 +12,7 @@ COMMENT = scalable, high-performance doc
> DISTNAME = mongodb-src-r3.2.13
> PKGNAME = ${DISTNAME:S/src-r//}
> CATEGORIES = databases
> -REVISION = 3
> +REVISION = 4
>
> HOMEPAGE = https://www.mongodb.com/
>
> Index: patches/patch-src_mongo_util_processinfo_openbsd_cpp
> ===================================================================
> RCS file:
> /cvs/ports/databases/mongodb/patches/patch-src_mongo_util_processinfo_openbsd_cpp,v
> retrieving revision 1.1
> diff -u -p -r1.1 patch-src_mongo_util_processinfo_openbsd_cpp
> --- patches/patch-src_mongo_util_processinfo_openbsd_cpp 8 Jun 2017
> 16:16:43 -0000 1.1
> +++ patches/patch-src_mongo_util_processinfo_openbsd_cpp 12 Jan 2019
> 12:59:25 -0000
> @@ -1,5 +1,8 @@
> $OpenBSD: patch-src_mongo_util_processinfo_openbsd_cpp,v 1.1 2017/06/08
> 16:16:43 sthen Exp $
>
> +- avoid use after free
> +- mincore(2) has been removed
> +
> Index: src/mongo/util/processinfo_openbsd.cpp
> --- src/mongo/util/processinfo_openbsd.cpp.orig
> +++ src/mongo/util/processinfo_openbsd.cpp
> @@ -27,3 +30,35 @@ Index: src/mongo/util/processinfo_openbs
> }
>
> double ProcessInfo::getSystemMemoryPressurePercentage() {
> +@@ -182,28 +184,14 @@ bool ProcessInfo::supported() {
> + }
> +
> + bool ProcessInfo::blockCheckSupported() {
> +- return true;
> ++ return false;
> + }
> +
> + bool ProcessInfo::blockInMemory(const void* start) {
> +- char x = 0;
> +- if (mincore((void*)alignToStartOfPage(start), getPageSize(), &x)) {
> +- log() << "mincore failed: " << errnoWithDescription() << endl;
> +- return 1;
> +- }
> +- return x & 0x1;
> ++ return false;
> + }
> +
> + bool ProcessInfo::pagesInMemory(const void* start, size_t numPages,
> vector<char>* out) {
> +- out->resize(numPages);
> +- // int mincore(const void *addr, size_t len, char *vec);
> +- if (mincore((void*)alignToStartOfPage(start), numPages * getPageSize(),
> &(out->front()))) {
> +- log() << "mincore failed: " << errnoWithDescription() << endl;
> +- return false;
> +- }
> +- for (size_t i = 0; i < numPages; ++i) {
> +- (*out)[i] = 0x1;
> +- }
> +- return true;
> ++ return false;
> + }
> + }
> Index: pkg/mongod.rc
> ===================================================================
> RCS file: /cvs/ports/databases/mongodb/pkg/mongod.rc,v
> retrieving revision 1.2
> diff -u -p -r1.2 mongod.rc
> --- pkg/mongod.rc 11 Jan 2018 19:27:01 -0000 1.2
> +++ pkg/mongod.rc 12 Jan 2019 12:59:25 -0000
> @@ -10,4 +10,8 @@ daemon_user="_mongodb"
>
> rc_reload=NO
>
> +rc_pre() {
> + install -d -m 755 -o _mongodb -g _mongodb /var/log/mongodb
> +}
> +
> rc_cmd $1
>
> --
> jca | PGP : 0x1524E7EE / 5135 92C1 AD36 5293 2BDF DDCC 0DFA 74AE 1524 E7EE
>
--
Antoine
