Cc-ing Andrew and Yosry On (25/01/29 16:28), Kenny Cheng wrote: > The zspage consists of multiple objects, each containing a "link struct" > to connect to the next object. The "link struct" is placed at the > beginning of each object. On a 32-bit system, the size of the "link > struct" is 4 bytes, which means the address returned by `zs_map_object` > is always 4-byte aligned. Sorry, you picked a rather unlucky time to patch zsmalloc, as it goes through some intrusive changes. We need to stabilize those changes first. > For better performance, zram compression/decompression is offloaded to > hardware designed by the IC vendor. For example, Realtek's hardware > requires 16-byte alignment. However, due to the 4-byte alignment, > a `memcpy` operation is needed to move data from the 4-byte aligned > address to the 16-byte aligned address, which negatively impacts zram > performance. Hmm, I don't know. If we change zsmalloc to make some H/W happy, how do we make sure that something that is good for Realtek is not "bad" for some other H/W? I'm very unsure about having "vendor-specific" (by the way, is that out-of-tree compression/decompression driver?) changes in zsmalloc.
