@@ -453,9 +601,36 @@ int ttm_pool_alloc(struct ttm_pool *pool, struct ttm_tt *tt, else gfp_flags |= GFP_HIGHUSER; - for (order = min_t(unsigned int, MAX_PAGE_ORDER, __fls(num_pages)); - num_pages; - order = min_t(unsigned int, order, __fls(num_pages))) { + order = min_t(unsigned int, MAX_PAGE_ORDER, __fls(num_pages)); + + if (tt->page_flags & TTM_TT_FLAG_PRIV_BACKED_UP) { + if (!tt->restore) { + gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; + + if (ctx->gfp_retry_mayfail) + gfp |= __GFP_RETRY_MAYFAIL; + + tt->restore = + kvzalloc(struct_size(tt-restore,old_pages, + (size_t)1 << order), gfp); + if (!tt->restore) + return -ENOMEM; + } else if (ttm_pool_restore_valid(tt-restore)) {+ struct ttm_pool_tt_restore *restore = tt-restore;+ + num_pages -= restore->alloced_pages; + order = min_t(unsigned int, order, __fls(num_pages)); + pages += restore->alloced_pages; + r = ttm_pool_restore_tt(restore, tt-backup, ctx);+ if (r) + return r; + caching = restore->caching_divide; + } + + tt->restore->pool = pool; + }Hui? Why is that part of the allocation function now? At bare minimum I would expect that this is a new function.It's because we now have partially backed up tts, so the restore is interleaved on a per-page basis, replacing the backup handles with page-pointers. I'll see if I can separate out at least the initialization here.Yeah, that kind of makes sense. My expectation was just that we now have explicit ttm_pool_swapout() and ttm_pool_swapin() functions.I fully understand, although in the allocation step, that would also increase the memory pressure since we might momentarily have twice the bo-size allocated, if the shmem object was never swapped out, and we don't want to unnecessarily risc OOM at recover time, although that should be a recoverable situation now. If the OOM receiver can free up system memory resources they can could potentially restart the recover.
What I meant was more that we have ttm_pool_swapout() which does a mix of moving each page to a swap backend and freeing one by one.
And ttm_pool_swapin() which allocates a bit of memory (usually one huge page) and then copies the content back in from the swap backend.
Alternatively we could rename ttm_pool_alloc() into something like ttm_pool_populate() and ttm_pool_free() into ttm_pool_unpopulate(), but those names are not very descriptive either.
It's just that we now do a bit more than just alloc and free in those functions, so the naming doesn't really match that well any more.
Christian.
/Thomas
