Hi, I'm the author of the article! Thank you for the awesome description of the various vm.dirty_* sysctls.
The problem described in my post was not _directly_ related to the kernel flushing dirty pages to disk. As such, I'm not sure that tweaking these sysctls would have made any difference.
Instead, we were seeing the kernel using too much CPU when it moved inodes from one cgroup to another. This is part of the kernel's writeback cgroup accounting logic. I believe this is a related but slightly different form of writeback problems :)
The problem described in my post was not _directly_ related to the kernel flushing dirty pages to disk. As such, I'm not sure that tweaking these sysctls would have made any difference.
Instead, we were seeing the kernel using too much CPU when it moved inodes from one cgroup to another. This is part of the kernel's writeback cgroup accounting logic. I believe this is a related but slightly different form of writeback problems :)