It was figured out that the track_pfn_insert changed the pgprot. I tried two ways to workaround it (1) change the pte in the fault callback directly (2) add a helper interface of devm_memremap_pages that has a pgprot.
The writethrough mmap seems to success but the final performance is really bad, just 20M/s per thread.... On 2020/12/14 6:44 下午, Wang Jianchao wrote: > Hi list > > We are trying to mmap the file in xfs-dax to userland with writethrough mode, > hope to avoid bandwidth and latency cause by write-allocate in writeback mode > and we can still use the original userland application code w/o using NTstore. > > We add following code in the mmap callback of xfs, > > vma->vm_page_prot = pgprot_writethrough(vma->vm_page_prot); > > But it seems to not work. When I use pcm-memory to check the bandwidth of PMM, > PMM read BW is still there which is nearly equal with PMM write. Even I use > pgprot_noncached, it still not work. > > What should I do to implement the writethrough mapping ? > > Thanks a million for any help. > > Jianchao > _______________________________________________ Linux-nvdimm mailing list -- [email protected] To unsubscribe send an email to [email protected]
