Messages in this thread | | | Subject | Re: [PATCH v12 02/11] mm, swap: Add infrastructure for saving page metadata on swap | From | Dave Hansen <> | Date | Mon, 5 Mar 2018 13:04:10 -0800 |
| |
On 03/05/2018 12:28 PM, Khalid Aziz wrote: >> Do you have a way to tell that data is not being thrown away? Like if >> the ADI metadata is different for two different cachelines within a >> single page? > > Yes, since access to tagged data is made using pointers with ADI tag > embedded in the top bits, any mismatch between what app thinks the ADI > tags should be and what is stored in the RAM for corresponding page will > result in exception. If ADI data gets thrown away, we will get an ADI > tag mismatch exception. If ADI tags for two different ADI blocks on a > page are different when app expected them to be the same, we will see an > exception on access to the block with wrong ADI data.
So, when an app has two different ADI tags on two parts of a page, the page gets swapped, and the ADI block size is under PAGE_SIZE, the app will get an ADI exception after swap-in through no fault of its own?
| |