b380148745
commit 18f14afe281648e31ed35c9ad2fcb724c4838ad9 upstream. There are reports of kernels crashing due to stack overflow while running OpenShift (Kubernetes). The primary contributor to the stack usage seems to be openvswitch, which is used by OVN-Kubernetes (based on OVN (Open Virtual Network)), but NFS also contributes in some stack traces. There may be some opportunities to reduce stack usage in the openvswitch code, but doing so potentially require tradeoffs vs performance, and also requires testing across architectures. Looking at stack usage across the kernel (using -fstack-usage), shows that ppc64le stack frames are on average 50-100% larger than the equivalent function built for x86-64. Which is not surprising given the minimum stack frame size is 32 bytes on ppc64le vs 16 bytes on x86-64. So increase the default stack size to 32KB for the modern 64-bit Book3S platforms, ie. pseries (virtualised) and powernv (bare metal). That leaves the older systems like G5s, and the AmigaOne (pasemi) with a 16KB stack which should be sufficient on those machines. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Aneesh Kumar K.V (IBM) <aneesh.kumar@kernel.org> Link: https://msgid.link/20231215124449.317597-1-mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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.