2016-05-20 5:20 GMT+09:00 Thomas Garnier <thgarnie@xxxxxxxxxx>: > I ran the test given by Joonsoo and it gave me these minimum cycles > per size across 20 usage: I can't understand what you did here. Maybe, it's due to my poor Engling. Please explain more. You did single thread test? Why minimum cycles rather than average? > size,before,after > 8,63.00,64.50 (102.38%) > 16,64.50,65.00 (100.78%) > 32,65.00,65.00 (100.00%) > 64,66.00,65.00 (98.48%) > 128,66.00,65.00 (98.48%) > 256,64.00,64.00 (100.00%) > 512,65.00,66.00 (101.54%) > 1024,68.00,64.00 (94.12%) > 2048,66.00,65.00 (98.48%) > 4096,66.00,66.00 (100.00%) It looks like performance of all size classes are the same? > I assume the difference is bigger if you don't have RDRAND support. What does RDRAND means? Kconfig? How can I check if I have RDRAND? > Christoph, Joonsoo: Do you think it would be valuable to add a CONFIG > to disable additional randomization per new page? It will remove > additional entropy but increase performance for machines without arch > specific randomization instructions. I don't think that it deserve another CONFIG. If performance is a matter, I think that removing additional entropy is better until it is proved that entropy is a problem. 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>