On (12/07/17 13:52), Gopi Sai Teja wrote: > If the length of the compressed page is greater than 75% of the PAGE_SIZE, > then the page is stored uncompressed in zram space. Zram space utilization > is improved if the threshold is 80%(5 compressed pages can be stored in > 4 pages). > > If the compressed length is greater than 3068 and less than 3261, pages > still can be stored in compressed form in zs_malloc class 3264. > Currently these compressed pages belong to 4096 zs malloc class.
so this makes sense. I had another idea awhile ago lkml.kernel.org/r/1456061274-20059-2-git-send-email-sergey.senozhat...@gmail.com in short, 3261 is good, but not as good as it possibly can be. for the time being, our huge-class watermark starts at 3264. but this can change. a side note, I think we have sort of wrong API. zsmalloc knows better which object is huge. and who knows, may be we will change the number of huge classes someday or huge-class watermark, etc. so having "hey zsmalloc, is this object huge or not" API seems to be better than ZRAM's enforcement "hey zsmalloc, this object is huge". -ss