On Mon, 16 Sep 2019, Pengfei Li wrote: > The name of KMALLOC_NORMAL is contained in kmalloc_info[].name, > but the names of KMALLOC_RECLAIM and KMALLOC_DMA are dynamically > generated by kmalloc_cache_name(). > > Patch1 predefines the names of all types of kmalloc to save > the time spent dynamically generating names. > > These changes make sense, and the time spent by new_kmalloc_cache() > has been reduced by approximately 36.3%. This is time spend during boot and does not affect later system performance. > Time spent by new_kmalloc_cache() > (CPU cycles) > 5.3-rc7 66264 > 5.3-rc7+patch_1-3 42188 Ok. 15k cycles during boot saved. So we save 5 microseconds during bootup? The current approach was created with the view on future setups allowing a dynamic configuration of kmalloc caches based on need. I.e. ZONE_DMA may not be needed once the floppy driver no longer makes use of it.
