On 29.03.2024 03:14, Yosry Ahmed wrote:
On Thu, Mar 28, 2024 at 1:06 PM Yosry Ahmed <yosryahmed@xxxxxxxxxx> wrote:
On Thu, Mar 28, 2024 at 12:11 PM Johannes Weiner <hannes@xxxxxxxxxxx> wrote:
On Mon, Mar 25, 2024 at 11:50:13PM +0000, Yosry Ahmed wrote:
There is no logical reason to refuse storing same-filled pages more
efficiently and opt for compression. Remove the userspace knob.
Signed-off-by: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
I also think the non_same_filled_pages_enabled option should go
away. Both of these tunables are pretty bizarre.
Happy to remove both in the next version :)
I thought non_same_filled_pages_enabled was introduced with the
initial support for same-filled pages, but it was introduced
separately (and much more recently):
https://lore.kernel.org/all/7dbafa963e8bab43608189abbe2067f4b9287831.1641247624.git.maciej.szmigiero@xxxxxxxxxx/
I am CCing Maciej to hear more about the use case for this.
Thanks for CCing me.
I introduced "non_same_filled_pages_enabled" a few years ago to
enable using zswap in a lightweight mode where it is only used for
its ability to store same-filled pages effectively.
As far as I remember, there were some interactions between full
zswap and the cgroup memory controller - like, it made it easier
for an aggressive workload to exceed its cgroup memory.high limits.
On the other hand, "same_filled_pages_enabled" sounds like some kind
of a debugging option since I don't see any real reason to disable it
either.
Thanks,
Maciej
