Jeff Moyer <jmoyer@xxxxxxxxxx> writes: > Dan Williams <dan.j.williams@xxxxxxxxx> writes: > >> When I read your patch I came away with the impression that ARM had >> not added memcpy_flushcache() yet and you were working around that >> fact. Now that I look, ARM *does* define memcpy_flushcache() and >> you're avoiding it. You use memcpy+arch_wb_pmem where arch_wb_pmem on >> ARM64 is defined as __clean_dcache_area_pop(dst, cnt). The ARM >> memcpy_flushcache() implementation is: >> >> memcpy(dst, src, cnt); >> __clean_dcache_area_pop(dst, cnt); >> >> So, I do not see how what you're doing is any less work unless you are >> flushing less than you copy? >> >> If memcpy_flushcache() is slower than memcpy + arch_wb_pmem then the >> ARM implementation is broken and that needs to be addressed not worked >> around in a driver. > > I think Mikulas wanted to batch up multiple copies and flush at the > end. According to his commit message, that batching gained him 2% > performance. Nevermind me, I just caught up with the rest of the thread. :) -Jeff -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
