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"); } .scm
e name the store resides on to the `operating-system-bootcfg' procedure, using the new BTRFS-SUBVOLUME-FILE-NAME argument. * doc/guix.texi (File Systems): Add a Btrfs subsection to document the use of subvolumes. * gnu/tests/install.scm (%btrfs-root-on-subvolume-os) (%btrfs-root-on-subvolume-os-source) (%btrfs-root-on-subvolume-installation-script) (%test-btrfs-root-on-subvolume-os): New variables.
AgeCommit message (Expand)Author
2019-06-07gnu: glibc-locales: Install symlinks using the normalized codeset....Fixes <https://bugs.gnu.org/36076>. Reported by Jack Hill <jackhill@jackhill.us> and Giovanni Biscuolo <g@xelera.eu> * gnu/build/locale.scm (locale->name+codeset): New file. * gnu/packages/base.scm (make-glibc-locales): Add #:modules and #:imported-modules. Add a 'symlink-normalized-codesets' phase. Ludovic Courtès
2019-06-07Add (gnu build locale)....* gnu/build/locale.scm: New file. * gnu/local.mk (MODULES_NOT_COMPILED): Add it. * gnu/installer/locale.scm (normalize-codeset): Remove. * gnu/system/locale.scm (localedef-command): Remove. (single-locale-directory): Use (gnu build locale). (glibc-supported-locales)[build]: Likewise, and remove 'read-supported-locales'. Ludovic Courtès
Maxim Cournoyer
2019-04-03gnu: Add configuration for depthcharge bootloader....* gnu/bootloader/depthcharge: New file. * gnu/local.mk [GNU_SYSTEM_MODULES]: Adjust accordingly. Signed-off-by: Ludovic Courtès <ludo@gnu.org> Timothy Sample