Messages in this thread | | | Date | Mon, 05 Aug 2002 11:16:52 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH] Rmap speedup |
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Rik van Riel wrote: > > On Mon, 5 Aug 2002, Daniel Phillips wrote: > > > > Despite the fact that the number of pte_chain references in > > > page_add/remove_rmap now just averages two in that test. > > > > It's weird that it only averages two. It's a four way and your running > > 10 in parallel, plus a process to watch for completion, right? > > I explained this one in the comment above the declaration of > struct pte_chain ;) > > * A singly linked list should be fine for most, if not all, workloads. > * On fork-after-exec the mapping we'll be removing will still be near > * the start of the list, on mixed application systems the short-lived > * processes will have their mappings near the start of the list and > * in systems with long-lived applications the relative overhead of > * exit() will be lower since the applications are long-lived.
I don't think so - the list walks in there are fairly long. What seems to be happening is that, as Daniel mentioned, all the pte_chains for page N happen to have good locality with the pte_chains for page N+1. Like parallel lines.
That might not hold up for longer-lived processes, slab cache fragmentation, longer chains, etc... - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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