mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-02-06 02:54:37 -05:00
eb83f6528b
HugeTLB pages have a struct page optimizations where struct pages for tail pages are freed. However, when HugeTLB pages are destroyed, the memory for struct pages (vmemmap) need to be allocated again. Currently, __GFP_NORETRY flag is used to allocate the memory for vmemmap, but given that this flag makes very little effort to actually reclaim memory the returning of huge pages back to the system can be problem. Lets use __GFP_RETRY_MAYFAIL instead. This flag is also performs graceful reclaim without causing ooms, but at least it may perform a few retries, and will fail only when there is genuinely little amount of unused memory in the system. Freeing a 1G page requires 16M of free memory. A machine might need to be reconfigured from one task to another, and release a large number of 1G pages back to the system if allocating 16M fails, the release won't work. Link: https://lkml.kernel.org/r/20230508234059.2529638-1-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Suggested-by: David Rientjes <rientjes@google.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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 Restructured Text 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.