Messages in this thread | | | Date | Fri, 25 Feb 2005 15:38:06 -0800 | From | Chris Wright <> | Subject | Re: [PATCH] allow vma merging with mlock et. al. |
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* Darren Hart (dvhltc@us.ibm.com) wrote: > As I understand it, the reason we don't merge is because > it is expected that a task will lock and unlock the same memory range > more than once and we don't want to waste our time merging and splitting > the VMAs.
I don't have a good sampling of applications. The one's I've used are temporal like gpg, or they mlockall the whole thing and never look back. But I did a quick benchmark since I was curious, a simple loop of a million lock/unlock cycles of a page that could trigger a merge:
vanilla (no merge): 659706 usecs
patched (merge): 3567020 usecs
Heh, I was surprised to see it that much slower.
cheers, -chris -- Linux Security Modules http://lsm.immunix.org http://lsm.bkbits.net - 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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