Messages in this thread | | | Date | Mon, 4 Feb 2008 17:13:57 -0800 | From | "Siddha, Suresh B" <> | Subject | issue with patch "x86: no CPA on iounmap" |
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This is wrt to x86 git commit f56d005d30342a45d8af2b75ecccc82200f09600 "x86: no CPA on iounmap"
This can use performance issue. When a GART driver unmaps a RAM page, which was mapped as UC, this commit will still retain UC attribute on the kernel identity mapping. This can cause mysterious performance issue if this freed page gets used by kernel later.
For now we should change the attribute during iounmap and in future PAT infrastructure will have necessary hooks to avoid the aliasing issues.
thanks, suresh
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