Messages in this thread | | | Date | Tue, 2 Sep 2003 04:30:38 -0700 | From | William Lee Irwin III <> | Subject | Re: cache limit |
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On Tue, Sep 02, 2003 at 07:52:51PM +0900, Takao Indoh wrote: > According to this information, many I/O increase pagecache and cause > memory shortage. > fadvise may be effective, but fadvise always releases cache > even if there are enough free memory, and may degrade performance. > In the case of /proc tunable, > pagecache is not released until system memory become lack. [...] > If so, limiting pagecache seems to be effective for DBMS.
There are reasons why databases use raw io and direct io; this is one of them. I'd say the kernel shouldn't try to engage in such tunable shenanigans.
-- wli - 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/ On Tue, Sep 02, 2003 at 07:52:51PM +0900, Takao Indoh wrote: > According to this information, many I/O increase pagecache and cause > memory shortage. > fadvise may be effective, but fadvise always releases cache > even if there are enough free memory, and may degrade performance. > In the case of /proc tunable, > pagecache is not released until system memory become lack. [...] > If so, limiting pagecache seems to be effective for DBMS.
There are reasons why databases use raw io and direct io; this is one of them. I'd say the kernel shouldn't try to engage in such tunable shenanigans.
-- wli - 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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