mainlining shenanigans
73b73bac90
memory.reclaim is a cgroup v2 interface that allows users to proactively reclaim memory from a memcg, without real memory pressure. Reclaim operations invoke vmpressure, which is used: (a) To notify userspace of reclaim efficiency in cgroup v1, and (b) As a signal for a memcg being under memory pressure for networking (see mem_cgroup_under_socket_pressure()). For (a), vmpressure notifications in v1 are not affected by this change since memory.reclaim is a v2 feature. For (b), the effects of the vmpressure signal (according to Shakeel [1]) are as follows: 1. Reducing send and receive buffers of the current socket. 2. May drop packets on the rx path. 3. May throttle current thread on the tx path. Since proactive reclaim is invoked directly by userspace, not by memory pressure, it makes sense not to throttle networking. Hence, this change makes sure that proactive reclaim caused by memory.reclaim does not trigger vmpressure. [1] https://lore.kernel.org/lkml/CALvZod68WdrXEmBpOkadhB5GPYmCXaDZzXH=yyGOCAjFRn4NDQ@mail.gmail.com/ [yosryahmed@google.com: update documentation] Link: https://lkml.kernel.org/r/20220721173015.2643248-1-yosryahmed@google.com Link: https://lkml.kernel.org/r/20220714064918.2576464-1-yosryahmed@google.com Signed-off-by: Yosry Ahmed <yosryahmed@google.com> Acked-by: Shakeel Butt <shakeelb@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: David Hildenbrand <david@redhat.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: NeilBrown <neilb@suse.de> Cc: Alistair Popple <apopple@nvidia.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| 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 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.