From d0084b2ee01bb146fdaf1fa6ae31f7ec4912668b Mon Sep 17 00:00:00 2001 From: Bahadir Balban Date: Fri, 21 Mar 2008 16:06:08 +0000 Subject: [PATCH] Trivial changes in comments for copy_on_write. --- tasks/mm0/src/fault.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/tasks/mm0/src/fault.c b/tasks/mm0/src/fault.c index ace33af..8eec490 100644 --- a/tasks/mm0/src/fault.c +++ b/tasks/mm0/src/fault.c @@ -258,9 +258,14 @@ struct page *copy_page(struct page *orig) /* TODO: * - Why not allocate a swap descriptor in vma_create_shadow() rather than * a bare vm_object? It will be needed. - * - Does vm_write clash with any other object flags??? * - Check refcounting of shadows, their references, page refs, * reduces increases etc. + * + * This handles copy-on-write semantics in various situations. + * + * 1) Copy-on-write of read-only files. (Creates r/w shadows/adds pages) + * 2) Copy-on-write of forked RO shadows (Creates r/w shadows/adds pages) + * 3) Copy-on-write of shm files. (Adds pages to r/w shm file from devzero). */ int copy_on_write(struct fault_data *fault) {