Messages in this thread | | | Date | Mon, 20 Dec 2004 19:24:07 +0100 | From | Manfred Spraul <> | Subject | Re: [RFC] Reimplementation of linux dynamic percpu memory allocator |
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Ravikiran G Thirumalai wrote:
>Hmmm..I knew from some experiments earlier that access to per cpu versions >of memory was slow with the slab based implementation -- which this patch >addresses, but I didn't know allocs themselves were slow... >Creation of a disk should not be a fast path no? > > No, not fast path. But it can happen a few thousand times. The slab implementation failed due to heavy internal fragmentation. If your code runs fine with a few thousand users, then there shouldn't be a problem.
>>> >>> >>That means no large pte entries for the per-cpu allocations, right? >>I think that's a bad idea for non-numa systems. What about a fallback to >>simple getfreepages() for non-numa systems? >> >> > >Can we have large pte entries with PAGE_SIZEd pages? > > > For non-NUMA systems, I would use get_free_pages() to allocate a multi-page area instead of map_vm_area(). Typically, get_free_pages() is backed by large pte memory and map_vm_area() by normal virtual memory.
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