On Thu, May 25, 2017 at 08:54:09AM -0700, Luigi Semenzato wrote: > Thank you Minchan, that's certainly simpler and I am annoyed that I > didn't consider that :/ > > By a quick look, there are a few differences but maybe they don't matter? > > 1. can a major (anon) fault result in a hit in the swap cache? So > pswpin will not get incremented and the fault will be counted as a > file fault. If it is swap cache hit, it's not a major fault which causes IO so VM count it as minor fault, not major. > > 2. pswpin also counts swapins from readahead --- which however I think > we have turned off (at least I hope so, since readahead isn't useful > with zram, in fact maybe zram should log a warning when readahead is > greater than 0 because I think that's the default). Yub, I expected you guys used zram with readahead off so it shouldn't be a big problem. About auto resetting readahead with zram, I agree with you. But there are some reasons I postpone the work. No want to discuss it in this thread/moment. ;) > > Incidentally, I understand anon and file faults, but what's a shmem fault? For me, it was out of my interest but if you want to count shmem fault, maybe, we need to introdue new stat(e.g., PSWPIN_SHM) in shmem_swapin but there are concrete reasons to justify in changelog. :) 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>
