Messages in this thread | | | From | David Laight <> | Subject | RE: [PATCH] powerpc/32: Move entry_32 functions just after HEAD functions. | Date | Wed, 19 Apr 2017 15:16:33 +0000 |
| |
From: Christophe Leroy > By default, PPC8xx PINs an ITLB on the first 8M of memory in order > to avoid any ITLB miss on kernel code. > However, with some debug functions like DEBUG_PAGEALLOC and > (soon to come) DEBUG_RODATA, the PINned TLB is invalidated soon > after startup so ITLB missed start to happen also on the kernel code. > > In order to avoid any ITLB miss in a critical section, we have to > ensure that their is no page boundary crossed between the setup of > a new value in SRR0/SRR1 and the associated RFI. This cannot be done > easily if entry_32 functions sits in the middle of other .text > functions. By placing entry_32 just after the .head section (as already > done for entry_64 on PPC64), we can more easily ensure the issue > doesn't happen.
Shouldn't this be done by putting all the functions that 'matter' into a named section instead of relying on the order of the input files? (Which is what I think this is doing.)
David
| |