On Thursday, June 3rd, 2021 at 3:57 PM, Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote: > How about this: > > - The client sets up a 1KiB shm file and sends it to the compositor. > - The client expands the file to 5KiB > - The compositor sees the new data up to 4KiB but zeroes past the 4KiB > mark. > > Does that still make userspace happy? As long as the new data in the expanded region is visible after a remapping the file with the new size, it should be fine. It doesn't matter that it's not visible without a munmap+mmap cycle.
