Linus Walleij
8e02b1b7fc
The current allocation of VMAP stack memory is using (THREADINFO_GFP & ~__GFP_ACCOUNT) which is a complicated way of saying (GFP_KERNEL | __GFP_ZERO): <linux/thread_info.h>: define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_ZERO) <linux/gfp_types.h>: define GFP_KERNEL_ACCOUNT (GFP_KERNEL | __GFP_ACCOUNT) This is an unfortunate side-effect of independent changes blurring the picture: commit19809c2da2changed (THREADINFO_GFP | __GFP_HIGHMEM) to just THREADINFO_GFP since highmem became implicit. commit9b6f7e163cthen added stack caching and rewrote the allocation to (THREADINFO_GFP & ~__GFP_ACCOUNT) as cached stacks need to be accounted separately. However that code, when it eventually accounts the memory does this: ret = memcg_kmem_charge(vm->pages[i], GFP_KERNEL, 0) so the memory is charged as a GFP_KERNEL allocation. Define a unique GFP_VMAP_STACK to use GFP_KERNEL | __GFP_ZERO and move the comment there. Link: https://lkml.kernel.org/r/20250509-gfp-stack-v1-1-82f6f7efc210@linaro.org Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Reported-by: Mateusz Guzik <mjguzik@gmail.com> Cc: Pasha Tatashin <pasha.tatashin@soleen.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 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.