[..] > > One thing I realized while reworking the patches for the batched checks is: > within zswap_store_page(), we set the entry->objcg and entry->pool before > adding it to the xarray. Given this, wouldn't it be safer to get the objcg > and pool reference per sub-page, locally in zswap_store_page(), rather than > obtaining batched references at the end if the store is successful? If we want > zswap_store_page() to be self-contained and correct as far as the entry > being created and added to the xarray, it seems like the right thing to do? > I am a bit apprehensive about the entry being added to the xarray without > a reference obtained on the objcg and pool, because any page-faults/writeback > that occur on sub-pages added to the xarray before the entire folio has been > stored, would run into issues. We definitely should not obtain references to the pool and objcg after initializing the entries with them. We can obtain all references in zswap_store() before zswap_store_page(). IOW, the batching in this case should be done before the per-page operations, not after. > > Just wanted to run this by you. The rest of the batched charging, atomic > and stat updates should be Ok. > > Thanks, > Kanchana > > > > > Thanks, > > Kanchana
