285189c78e
nf_ct_alloc_hashtable is used to allocate memory for conntrack, NAT bysrc and expectation hashtable. Assuming 64k bucket size, which means 7th order page allocation, __get_free_pages, called by nf_ct_alloc_hashtable, will trigger the direct memory reclaim and stall for a long time, when system has lots of memory stress so replace combination of __get_free_pages and vzalloc with kvmalloc_array, which provides a overflow check and a fallback if no high order memory is available, and do not retry to reclaim memory, reduce stall and remove nf_ct_free_hashtable, since it is just a kvfree Signed-off-by: Zhang Yu <zhangyu31@baidu.com> Signed-off-by: Wang Li <wangli39@baidu.com> Signed-off-by: Li RongQing <lirongqing@baidu.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.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.
See Documentation/00-INDEX for a list of what is contained in each file.
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.