d635ccdb43
Now the tmpfs can allow to allocate any sized large folios, and the default huge policy is still preferred to be 'never'. Due to tmpfs not behaving like other file systems in some cases as previously explained by David[1]: : I think I raised this in the past, but tmpfs/shmem is just like any : other file system .. except it sometimes really isn't and behaves much : more like (swappable) anonymous memory. (or mlocked files) : : There are many systems out there that run without swap enabled, or with : extremely minimal swap (IIRC until recently kubernetes was completely : incompatible with swapping). Swap can even be disabled today for shmem : using a mount option. : : That's a big difference to all other file systems where you are : guaranteed to have backend storage where you can simply evict under : memory pressure (might temporarily fail, of course). : : I *think* that's the reason why we have the "huge=" parameter that also : controls the THP allocations during page faults (IOW possible memory : over-allocation). Maybe also because it was a new feature, and we only : had a single THP size. Thus adding a new command line to change the default huge policy will be helpful to use the large folios for tmpfs, which is similar to the 'transparent_hugepage_shmem' cmdline for shmem. [1] https://lore.kernel.org/all/cbadd5fe-69d5-4c21-8eb8-3344ed36c721@redhat.com/ Link: https://lkml.kernel.org/r/ff390b2656f0d39649547f8f2cbb30fcb7e7be2d.1732779148.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Daniel Gomez <da.gomez@samsung.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Lance Yang <ioworker0@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .clippy.toml | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
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.