On Tue, 17 Mar 2015 17:22:46 +0900 Roman Peniaev <r.peniaev@xxxxxxxxx> wrote: > >> My second patch fixes this problem. > >> I occupy the block on allocation and avoid jumping to the search loop. > > > > I'm not sure that this fixes above case. > > 'vm_map_ram (3) * 85' means 85 times vm_map_ram() calls. > > > > First vm_map_ram(3) caller could get benefit from your second patch. > > But, second caller and the other callers in each iteration could not > > get benefit and should iterate whole list to find suitable free block, > > because this free block is put to the tail of the list. Am I missing > > something? > > You are missing the fact that we occupy blocks in 2^n. > So in your example 4 page slots will be occupied (order is 2), not 3. Could you please - update the changelogs so they answer the questions which Joonsoo Kim and Gioh Kim asked - write a little in-kernel benchmark to test the scenario which Joonsoo described and include the before and after timing results in the changelogs - resend the patchset Thanks. -- 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>