085ff35e76
The GFP flags from vma_thp_gfp_mask() according to user configuration only used for large folio allocation but not for memory cgroup charge, and GFP_KERNEL is used for both order-0 and large order folio when memory cgroup charge at present. However, mem_cgroup_charge() uses the GFP flags in a fairly sophisticated way. In addition to checking gfpflags_allow_blocking(), it pays attention to __GFP_NORETRY and __GFP_RETRY_MAYFAIL to ensure that processes within this memcg do not exceed their quotas. So we'd better to move mem_cgroup_charge() into alloc_anon_folio(), 1) it will make us to allocate as much as possible large order folio, because we could try the next order if mem_cgroup_charge() fails, although the memcg's memory usage is close to its limits. 2) using same GFP flags for allocation and charge is to be consistent with PMD THP firstly, in addition, according to GFP flag returned from vma_thp_gfp_mask(), GFP_TRANSHUGE_LIGHT could make us skip direct reclaim, _GFP_NORETRY will make us skip mem_cgroup_oom() and won't trigger memory cgroup oom from large order(order <= COSTLY_ORDER) folio charging. Link: https://lkml.kernel.org/r/20240122011612.501029-1-wangkefeng.wang@huawei.com Link: https://lkml.kernel.org/r/20240117103954.2756050-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Muchun Song <songmuchun@bytedance.com> 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.