ghc runtime by default (otherwise depending on a "configure" option) does memory allocation on their own by first mmapping a 1 TB range of memory into the process and then parceling out chunks from it. If one of the chunks is not needed, the kernel needs to be informed - otherwise the system would quickly run out of available RAM. ghc does that via madvise(2). There are two options when doing this informing: MADV_FREE - Means "I don't need this range or the data in it any more". Kernel promises to fail later accesses to it. MADV_DONTNEED - Means "I don't need this range right now - and I don't need the data in it anymore". Kernel promises to make later accesses to it succeed (if necessary by providing a new page initialized with zeroes). MADV_FREE was introduced in Linux 4.5. glibc 2.25 and later always define MADV_FREE. Unpatched ghc 8.0.2 will use either MADV_FREE or MADV_DONTNEED, determined at ghc compile time. Which of them will actually succeed is determined by the Linux kernel at run time. This patch makes ghc try MADV_FREE. If it doesn't work, it falls back to MADV_DONTNEED. The end result is that ghc programs free their memory with Linux < 4.5 again. See https://git.haskell.org/ghc.git/commitdiff/6576bf83cdf4eac05eb88a24aa934a736c91e3da for more information. --- a/rts/posix/OSMem.c +++ b/rts/posix/OSMem.c @@ -541,11 +541,24 @@ void osDecommitMemory(void *at, W_ size) #ifdef MADV_FREE // Try MADV_FREE first, FreeBSD has both and MADV_DONTNEED - // just swaps memory out + // just swaps memory out. Linux >= 4.5 has both DONTNEED and FREE; either + // will work as they both allow the system to free anonymous pages. + // It is important that we try both methods as the kernel which we were + // built on may differ from the kernel we are now running on. r = madvise(at, size, MADV_FREE); -#else - r = madvise(at, size, MADV_DONTNEED); + if(r < 0) { + if (errno == EINVAL) { + // Perhaps the system doesn't support MADV_FREE; fall-through and + // try MADV_DONTNEED. + } else { + sysErrorBelch("unable to decommit memory"); + } + } else { + return; + } #endif + + r = madvise(at, size, MADV_DONTNEED); if(r < 0) sysErrorBelch("unable to decommit memory"); } a>
AgeCommit message (Expand)Author
2020-02-02gnu: tlp: Update to 1.3.0....* gnu/packages/linux.scm (tlp): Update to 1.3.0. [source]: Hard-code name in origin URI. [native-inputs]: Add "shellcheck". [arguments]: Activate some tests. Update environment variables. Ignore tlp-rdw man pages. * gnu/services/pm.scm (tlp-activation): Update configuration file name. Nicolas Goaziou
2019-08-26services: tlp, thermald: Add descriptions....* gnu/services/pm.scm (tlp-service-type)[description]: New field. (thermald-service-type)[description]: New field. Ludovic Courtès
2018-06-20services: Fix GPLv3 header in cuirass and pm modules....* gnu/services/cuirass.scm, gnu/services/pm.scm: Adjust to canonical GPLv3 header used throughout Guix. Signed-off-by: Leo Famulari <leo@famulari.name> Nils Gillmann
2017-05-14services: Add 'thermald-service-type'....* gnu/services/pm.scm (<thermald-configuration>): New record type. (thermald-shepherd-service, thermald-service-type): New variables. * doc/guix.texi (Thermal Management): New section documenting thermald. Christopher Allan Webber
2017-04-16services: Add a default value to various service types....* gnu/services/admin.scm (rottlog-service-type)[default-value]: New field. * gnu/services/base.scm (guix-service-type)[default-value]: New field. (guix-publish-service-type)[default-value]: New field. * gnu/services/cups.scm (cups-service-type)[default-value]: New field. * gnu/services/dict.scm (dicod-service-type)[default-value]: New field. * gnu/services/mcron.scm (mcron-service-type)[default-value]: New field. * gnu/services/networking.scm (<tor-configuration>)[config-file]: Add default value. (tor-service-type)[default-value]: New field. (<bitlbee-configuration>)[interface, port, extra-settings]: Add default values. (bitlbee-service-type)[default-value]: New field. (wpa-supplicant-service-type)[default-value]: New field. (tlp-service-type)[default-value]: New field. (openssh-service-type)[default-value]: New field. * doc/guix.texi (Base Services, Log Rotation) (Networking Services, Printing Services): (Power management Services): Adjust examples accordingly. Ludovic Courtès
2017-03-31doc: Fix typos....* doc/guix.texi (Build Systems)[ocaml-build-system]: Fix typo. (Log Rotation)[periodic-rotations]: ditto. (Database Services)[redis-service-type]: ditto. (OpenSMTPD Service)[opensmtpd-configuration]: ditto. (VPN Services)[OpenVPN]: ditto. (Power management Services)[tlp-configuration]: ditto. (Git daemon service)[git-daemon-service]: ditto. (Running GuixSD in a VM): ditto. * gnu/services/pm.scm (tlp-configuration)[runtime-pm-blacklist]: Fix typo. * gnu/services/vpn.scm (openvpn-client-configuration)[status]: ditto. Eric Bavier
2017-03-24gnu: Add tlp service....* gnu/services/pm.scm: New file. * gnu/local.mk (GNU_SYSTEM_MODULES): Add gnu/services/tlp.scm. * doc/guix.texi (Power management Services): New section. Signed-off-by: Clément Lassieur <clement@lassieur.org> Mathieu Othacehe