On Wed, Jan 18, 2017 at 12:21 PM, Michael Layzell <mich...@thelayzells.com> wrote:
> Summary: > Games implemented on the web platform using WASM or asm.js use large > contiguous blocks of allocated memory as their backing store for game > memory. For complex games, these allocations can be quite large, sometimes > as large as 1GB. In 64-bit builds, we have no problem finding a large > enough section of virtual memory that we can allocate a large contiguous > hunk. Unfortunately normal use of Firefox quickly fragments the smaller > address space of 32-bit Firefox, meaning that these complex games often > fail to run. > > The Large-Allocation header is a hint header for a document. It tells the > browser that the web content in the to-be-loaded page is going to want to > perform a large contiguous memory allocation. In our current implementation > of this feature, we handle this hint by starting a dedicated process for > the to-be-loaded document, and loading the document inside of that process > instead. Further top-level navigations in that "Fresh Process" will cause > the process to be discarded, and the browsing context will shift back to > the primary content process. > > We hope to ship this header alongside WASM in Firefox 52 to enable game > developers to develop more intense games on our web platform. More details > on the implementation and limitations of this header and our implementation > can be found in the linked bug. > > Bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1331083 > > Link to standard: This feature is non-standard > Hmm... Do you intend to publish this with IANA using the procedures specified in: https://tools.ietf.org/html/rfc3864 DevTools bug: none > > Do other browser engines implement this? > No, we are in conversations with Chrome about them potentially also > recognizing this hint. > > Tests: Added as part of the implementation > > Security & Privacy Concerns: none > I share MT's concerns here. It seems like minimally there are DoS concerns here, but also potentially concerns about being able to force other Large Allocation requesters onto the same process (to the extent to which being on other processes is valuable). -Ekr _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
