On 02/23/2016 11:47 PM, Dave Chinner wrote: <> > > i.e. what we've implemented right now is a basic, slow, > easy-to-make-work-correctly brute force solution. That doesn't mean > we always need to implement it this way, or that we are bound by the > way dax_clear_sectors() currently flushes cachelines before it > returns. It's just a simple implementation that provides the > ordering the *filesystem requires* to provide the correct data > integrity semantics to userspace. > Or it can be written properly with movnt instructions and be even faster the a simple memset, and no need for any cl_flushing let alone any radix-tree locking. That said your suggestion above is 25%-100% slower than current code because the cl_flushes will be needed eventually, and the atomics of a lock takes 25% the time of a full page copy. You are forgetting we are talking about memory and not harddisk. the rules are different. (Cumming from NFS it took me a long time to adjust) I'll send a patch to fix this Thanks Boaz -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>