Linux kernel source tree
Go to file
Jinjiang Tu aabf58bfaa mm/hugetlb: fix set_max_huge_pages() when there are surplus pages
In set_max_huge_pages(), min_count is computed taking into account surplus
huge pages, which might lead in some cases to not be able to free huge
pages and end up accounting them as surplus instead.

One way to solve it is to subtract surplus_huge_pages directly, but we
cannot do it blindly because there might be surplus pages that are also
free pages, which might happen when we fail to restore the vmemmap for
optimized hvo pages.  So we could be subtracting the same page twice.

In order to work this around, let us first compute the number of free
persistent pages, and use that along with surplus pages to compute
min_count.

Steps to reproduce:
1) create 5 hugetlb folios in Node0
2) run a program to use all the hugetlb folios
3) echo 0 > nr_hugepages for Node0 to free the hugetlb folios.  Thus
   the 5 hugetlb folios in Node0 are accounted as surplus.
4) create 5 hugetlb folios in Node1
5) echo 0 > nr_hugepages for Node1 to free the hugetlb folios

The result:
        Node0    Node1
Total     5         5
Free      0         5
Surp      5         5

The result with this patch:
        Node0    Node1
Total     5         0
Free      0         0
Surp      5         0

Link: https://lkml.kernel.org/r/20250409055957.3774471-1-tujinjiang@huawei.com
Link: https://lkml.kernel.org/r/20250407124706.2688092-1-tujinjiang@huawei.com
Fixes: 9a30523066 ("hugetlb: add per node hstate attributes")
Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com>
Acked-by: Oscar Salvador <osalvador@suse.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-11 17:32:40 -07:00
arch A set of final cleanups for the timer subsystem: 2025-04-06 08:35:37 -07:00
block treewide: Switch/rename to timer_delete[_sync]() 2025-04-05 10:30:12 +02:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto This push fixes reverts the multibuffer hash testing as it is buggy. 2025-04-02 09:14:59 -07:00
Documentation mseal: fix typo and style in documentation 2025-04-11 17:32:35 -07:00
drivers fpga: tests: add module descriptions 2025-04-11 17:32:38 -07:00
fs Miscellaneous scheduler fixes/updates: 2025-04-06 10:44:58 -07:00
include locking/local_lock, mm: replace localtry_ helpers with local_trylock_t type 2025-04-11 17:32:35 -07:00
init Miscellaneous scheduler fixes/updates: 2025-04-06 10:44:58 -07:00
io_uring io_uring: always do atomic put from iowq 2025-04-03 08:31:57 -06:00
ipc treewide: const qualify ctl_tables where applicable 2025-01-28 13:48:37 +01:00
kernel Fix a perf events time accounting bug. 2025-04-06 10:48:12 -07:00
lib kunit: slub: add module description 2025-04-11 17:32:39 -07:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm mm/hugetlb: fix set_max_huge_pages() when there are surplus pages 2025-04-11 17:32:40 -07:00
net treewide: Switch/rename to timer_delete[_sync]() 2025-04-05 10:30:12 +02:00
rust Kbuild updates for v6.15 2025-04-05 15:46:50 -07:00
samples samples/livepatch: add module descriptions 2025-04-11 17:32:38 -07:00
scripts Disable SLUB_TINY for build testing 2025-04-06 10:00:04 -07:00
security mseal sysmap: kernel config and header change 2025-04-01 15:17:14 -07:00
sound soundwire fix for 6.15-rc1 2025-04-06 12:04:53 -07:00
tools selftests/mm: generate a temporary mountpoint for cgroup filesystem 2025-04-11 17:32:37 -07:00
usr kbuild: hdrcheck: fix cross build with clang 2025-03-05 04:06:45 +09:00
virt ARM: 2025-03-25 14:22:07 -07:00
.clang-format clang-format: Update with v6.11-rc1's for_each macro list 2024-08-02 13:20:31 +02:00
.clippy.toml rust: give Clippy the minimum supported Rust version 2025-01-10 00:17:25 +01:00
.cocciconfig
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: Retire Ralf Baechle 2024-11-12 15:48:59 +01:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: Create intermediate vmlinux build with relocations preserved 2025-03-17 00:29:50 +09:00
.mailmap mailmap: map Loic Poulain's old email addresses 2025-04-11 17:32:34 -07:00
.rustfmt.toml
COPYING
CREDITS Including fixes from netfilter. 2025-04-04 09:15:35 -07:00
Kbuild drm: ensure drm headers are self-contained and pass kernel-doc 2025-02-12 10:44:43 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS MAINTAINERS: add Andrew and Baoquan as kexec maintainers 2025-04-11 17:32:37 -07:00
Makefile Linux 6.15-rc1 2025-04-06 13:11:33 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.