Messages in this thread | | | Date | Wed, 19 Jul 2006 11:44:27 +0800 | From | "yunfeng zhang" <> | Subject | Re: Improvement on memory subsystem |
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> On Tue, 18 Jul 2006 18:03:54 +0800, yunfeng zhang said: > > But wouldn't that end up causing a seek storm, rather than handling the pages > in the order that minimizes the total seek distance, no matter where they are > in memory? Remember - if you have a 2Ghz processor, and a disk that seeks in 1 > millisecond, every seek is (*very* roughly) about 2 million instructions. So > if we can burn 20 thousand instructions finding a read order that eliminates > *one* seek, we're 1.98M instructions ahead.
Further sample is showd below
to page-fault (page-in operation) scan the pte triggering page-fault and its following ptes in its VMA, if its followers are swap_entry_t type and their relative offset is enough closer to the host pte, read them together.
to swap daemon (page-out operation), let's scan every pte of a VMA in the OS, if we find an appropriate candidate, lock it and its following ptes if all ptes are appropriate swap-out objects, then allocate a consecutive swap pages from swap space, if we're success, do an efficient asynchronous IO operation; if we're failed, shrink those ptes.
Isn't it right?
By the way, all improvements listed by me are introduced briefly, most of them are complex, maybe only my documentation can descript them clearly. - 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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