On Mon, Sep 16, 2019 at 10:58:06AM +0300, Jarkko Sakkinen wrote: > On Mon, Sep 16, 2019 at 07:14:00AM +0300, Jarkko Sakkinen wrote: > > My flush of updates for v23. Contains a bunch of clean ups and bug > > fixes with the main focus on the page reclaimer. The main goal has > > been to disclose all the other possibilities for failure after > > ENCLS[EBLOCK] other than EPCM conflict when the whole EPC is > > invalidated. > > I have at least one more update to the reclaimer but want to merge these > first. > > It adds optional struct epc_page **reclaimed_page to > sgx_reclaim_pages(). If NULL, the function will just append everything > to the free pool. Otherwise, it will use it to return one of the > reclaimed pages if there are any. > > sgx_alloc_page() then does the following when @reclaim=true: > > 1. If page in free page pool, take one. > 2. If not, try to reclaim one. > 3. If nothing was reclaimed -ENOMEM. > > Right now sgx_alloc_page() can in theory take however long. > > I wonder why we do not return -ENOMEM also when @reclaim=false. Where > did this returning -EBUSY came from? Can't recall. Checked. I guess it is just for ELDU flow but does not make sense otherwise. Tuning sgx_vma_fault() should be enough. I mean with the above change we would start to return -EBUSY sometimes in OOM situations. /Jarkko
