On 8/22/2018 7:59 AM, Mikulas Patocka wrote:
I did some tests on framebuffer and found out that "read+read+write+write" is faster than "read+write+read+write" - that may suggest that the reads flush the write queue.
I think we are worried about correctness at this moment like a raw_read following raw_write is getting ahead of raw_write and reading some stale
data. I think a test scenario for this can be constructed as follows: 1. raw_write magic 2. raw_read 3. fail if value is not magic 4. barrier to go to sane state 5. raw_write magic2 6. barrier to ensure magic2 is observed 7. goto 1 If raw_read is getting ahead of raw_write, it should observe magic2 at step #3.