Messages in this thread | | | Subject | Re: [PATCH V5 0/9] Fixes for vhost metadata acceleration | From | Jason Wang <> | Date | Thu, 15 Aug 2019 11:28:05 +0800 |
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On 2019/8/14 上午12:41, Christoph Hellwig wrote: > On Tue, Aug 13, 2019 at 08:57:07AM -0300, Jason Gunthorpe wrote: >> On Tue, Aug 13, 2019 at 04:31:07PM +0800, Jason Wang wrote: >> >>> What kind of issues do you see? Spinlock is to synchronize GUP with MMU >>> notifier in this series. >> A GUP that can't sleep can't pagefault which makes it a really weird >> pattern > get_user_pages/get_user_pages_fast must not be called under a spinlock. > We have the somewhat misnamed __get_user_page_fast that just does a > lookup for existing pages and never faults for a few places that need > to do that lookup from contexts where we can't sleep.
Yes, I do use __get_user_pages_fast() in the code.
Thanks
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