Messages in this thread | | | From | Linus Torvalds <> | Date | Mon, 28 Sep 2020 09:17:09 -0700 | Subject | Re: [PATCH 1/5] mm: Introduce mm_struct.has_pinned |
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On Mon, Sep 28, 2020 at 5:49 AM Jason Gunthorpe <jgg@ziepe.ca> wrote: > > Not seeing an obvious option besides adding a smp_mb() before > page_maybe_dma_pinned() as Peter once suggested.
That is going to be prohibitively expensive - needing it for each pte whether it's pinned or not.
I really think the better option is a "don't do that then". This has _never_ worked before either except by pure luck.
I also doubt anybody does it. forking with threads is a bad idea to begin with. Doing so while pinning pages even more so.
Linus
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