Messages in this thread | | | Date | Tue, 15 Jan 2008 11:55:30 +0000 | From | "Jan Beulich" <> | Subject | Re: [PATCH] [0/31] Great change_page_attr patch series v2 |
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>> The one concept that I'm missing (but that I can easily produce a follow-up >> patch for, as I had this in my c_p_a() changes) is the tracking and adjusting >> of the reference protection for a large page range that got fully converted >> to another type (namely relevant for .rodata if it exceeds 2/4 Mb), allowing >> to use a large page mapping in this case even for non-default mappings. > >Ah -- i got rid of that by changing the rodata code to not do this >except for the debugging case > >>> >CPA: Only unmap kernel init pages in text mapping when CONFIG_DEBUG_RODATA is set > >Otherwise the kernel will likely always run with 4K pages instead of 2MB pages, >which is costly in terms of TLBs. ><< > >But you're right that would be an useful feature. But wouldn't it require >aligning rodata to 2MB in the vmlinux to be really effective?
Yes, that would be desirable then (and .data should be at a 2/4 Mb boundary for this, too).
Jan
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