Introducing what I call detached freelist, for improving the performance of object freeing in the "slowpath" of kmem_cache_free_bulk, which calls __slab_free(). The benchmarking tool are avail here: https://github.com/netoptimizer/prototype-kernel/tree/master/kernel/mm See: slab_bulk_test0{1,2,3}.c Compared against existing bulk-API (in AKPMs tree), we see a small regression for the fastpath (between 2-5 cycles), but a huge improvement for the slowpath. bulk- Bulk-API-before - Bulk-API with patchset 1 - 42 cycles(tsc) 10.520 ns - 47 cycles(tsc) 11.931 ns - improved -11.9% 2 - 26 cycles(tsc) 6.697 ns - 29 cycles(tsc) 7.368 ns - improved -11.5% 3 - 22 cycles(tsc) 5.589 ns - 24 cycles(tsc) 6.003 ns - improved -9.1% 4 - 19 cycles(tsc) 4.921 ns - 22 cycles(tsc) 5.543 ns - improved -15.8% 8 - 17 cycles(tsc) 4.499 ns - 20 cycles(tsc) 5.047 ns - improved -17.6% 16 - 69 cycles(tsc) 17.424 ns - 20 cycles(tsc) 5.015 ns - improved 71.0% 30 - 88 cycles(tsc) 22.075 ns - 20 cycles(tsc) 5.062 ns - improved 77.3% 32 - 83 cycles(tsc) 20.965 ns - 20 cycles(tsc) 5.089 ns - improved 75.9% 34 - 80 cycles(tsc) 20.039 ns - 28 cycles(tsc) 7.006 ns - improved 65.0% 48 - 76 cycles(tsc) 19.252 ns - 31 cycles(tsc) 7.755 ns - improved 59.2% 64 - 86 cycles(tsc) 21.523 ns - 68 cycles(tsc) 17.203 ns - improved 20.9% 128 - 97 cycles(tsc) 24.444 ns - 72 cycles(tsc) 18.195 ns - improved 25.8% 158 - 96 cycles(tsc) 24.036 ns - 73 cycles(tsc) 18.372 ns - improved 24.0% 250 - 100 cycles(tsc) 25.007 ns - 73 cycles(tsc) 18.430 ns - improved 27.0% Patchset based on top of commit aefbef10e3ae with previous accepted bulk patchset(V2) applied (avail in AKPMs quilt). Small note, benchmark run with kernel compiled with .config CONFIG_FTRACE in-order to use the perf probes to measure the amount of page bulking into __slab_free(). While running the "worse-case" testing module slab_bulk_test03.c --- Jesper Dangaard Brouer (3): slub: extend slowpath __slab_free() to handle bulk free slub: optimize bulk slowpath free by detached freelist slub: build detached freelist with look-ahead mm/slub.c | 141 ++++++++++++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 111 insertions(+), 30 deletions(-) -- Best regards, Jesper Dangaard Brouer MSc.CS, Sr. Network Kernel Developer at Red Hat LinkedIn: http://www.linkedin.com/in/brouer -- 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>