Messages in this thread | | | From | Qian Cai <> | Subject | Re: [PATCH V15] mm/debug: Add tests validating architecture page table helpers | Date | Fri, 6 Mar 2020 19:34:18 -0500 |
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> On Mar 6, 2020, at 7:03 PM, Anshuman Khandual <Anshuman.Khandual@arm.com> wrote: > > Hmm, set_pte_at() function is not preferred here for these tests. The idea > is to avoid or atleast minimize TLB/cache flushes triggered from these sort > of 'static' tests. set_pte_at() is platform provided and could/might trigger > these flushes or some other platform specific synchronization stuff. Just
Why is that important for this debugging option?
> wondering is there specific reason with respect to the soft lock up problem > making it necessary to use set_pte_at() rather than a simple WRITE_ONCE() ?
Looks at the s390 version of set_pte_at(), it has this comment, vmaddr);
/* * Certain architectures need to do special things when PTEs * within a page table are directly modified. Thus, the following * hook is made available. */
I can only guess that powerpc could be the same here.
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