On Mon, 2007-08-06 at 12:31 -0700, Daniel Phillips wrote: > On Monday 06 August 2007 11:17, Peter Zijlstra wrote: > > And how do we know a page was taken out of the reserves? > > Why not return that in the low bit of the page address? This is a > little more cache efficient, does not leave that odd footprint in the > page union and forces the caller to examine the > alloc_pages(...P_MEMALLOC) return, making it harder to overlook the > fact that it got a page out of reserve and forget to put one back > later.
This would require auditing all page allocation sites to ensure they ever happen under PF_MEMALLOC or the like. Because if an allocator ever fails to check the low bit and assumes its a valid struct page *, stuff will go *bang*. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
