On Mon, Jun 10, 2024 at 7:45 PM Yosry Ahmed <yosryahmed@xxxxxxxxxx> wrote: > > Add zswap_never_enabled() to skip the xarray lookup in zswap_load() if > zswap was never enabled on the system. It is implemented using static > branches for efficiency, as enabling zswap should be a rare event. This > could shave some cycles off zswap_load() when CONFIG_ZSWAP is used but > zswap is never enabled. > > However, the real motivation behind this patch is two-fold: > - Incoming large folio swapin work will need to fallback to order-0 > folios if zswap was ever enabled, because any part of the folio could > be in zswap, until proper handling of large folios with zswap is > added. > > - A warning and recovery attempt will be added in a following change in > case the above was not done incorrectly. Zswap will fail the read if > the folio is large and it was ever enabled. > > Signed-off-by: Yosry Ahmed <yosryahmed@xxxxxxxxxx> This LGTM. Reviewed-by: Nhat Pham <nphamcs@xxxxxxxxx>
