Messages in this thread | | | Date | Thu, 7 Jul 2016 16:37:42 +0100 | From | Catalin Marinas <> | Subject | Re: [PATCH 1/1] arm64/hugetlb: clear PG_dcache_clean if the page is dirty when munmap |
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On Thu, Jul 07, 2016 at 08:09:04PM +0800, Zhen Lei wrote: > At present, PG_dcache_clean is only cleared when the related huge page > is about to be freed. But sometimes, there maybe a process is in charge > to copy binary codes into a shared memory, and notifies other processes > to execute base on that. For the first time, there is no problem, because > the default value of page->flags is PG_dcache_clean cleared. So the cache > will be maintained at the time of set_pte_at for other processes. But if > the content of the shared memory have been updated again, there is no > cache operations, because the PG_dcache_clean is still set. > > For example: > Process A > open a hugetlbfs file > mmap it as a shared memory > copy some binary codes into it > munmap > > Process B > open the hugetlbfs file > mmap it as a shared memory, executable > invoke the functions in the shared memory > munmap > > repeat the above steps.
Does this work as you would expect with small pages (and for example shared file mmap)? I don't want to have a different behaviour between small and huge pages.
-- Catalin
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