On (22/10/24 13:59), Andrew Morton wrote: > > It makes no sense for us to recompress the object if it will > > be in the same size class. We anyway don't get any memory gain. > > But, at the same time, we get a CPU time overhead when inserting > > this object into zspage and decompressing it afterwards. > > > > Dumb question: is it ever possible for compression to result in an > increase in size? That's a good question. Re-compressed object can be bigger than the original compressed one, but this should already be taken care of. We do if (comp_len_next >= huge_class_size || comp_len_next >= comp_len_prev || This checks whether recompressed object is above huge-size watermark and whether recompressed size is larger than the original size.