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authorMichael Ellerman <mpe@ellerman.id.au>2023-12-15 23:44:49 +1100
committerAneesh Kumar K.V (IBM) <aneesh.kumar@kernel.org>2024-01-19 00:10:14 +0530
commit18f14afe281648e31ed35c9ad2fcb724c4838ad9 (patch)
tree8d11b04f46996d6c2363359d92c2bb6543969c48 /arch
parentd2441d3e8c0c076d0a2e705fa235c76869a85140 (diff)
powerpc/64s: Increase default stack size to 32KB
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
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/Kconfig1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 6f105ee4f3cf..2df545c1446e 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -858,6 +858,7 @@ config THREAD_SHIFT
int "Thread shift" if EXPERT
range 13 15
default "15" if PPC_256K_PAGES
+ default "15" if PPC_PSERIES || PPC_POWERNV
default "14" if PPC64
default "13"
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