On Thursday 22 January 2009 05:59:39 Dave Hansen wrote: > Let's take, for instance, a 1-byte reservation. With this code, you've > suddenly turned that into a 0-byte reservation, and that *can't* be > right. The same thing happens if you have a reservation that spans two > pages. If you unconditionally round it down, then you might miss the > part that spans a portion of the second page. > > It needs to be rounded down like you are suggesting here, but only in > the case where we've gone over the *CURRENT* node's boundary. This is > kinda what that "if (end_pfn > node_ar.end_pfn)" check is doing. But, > it evidently screws it up if the overlap isn't by an entire page or > something.
I assumed the condition 'while (start_pfn < end_pfn && .. )' asks for atleast a PAGE_SIZE difference between them and hence went ahead with that patch. My guess was a 1-byte , 2-byte or a (PAGE_SIZE -1)-byte reservations may not even go into that loop. However we just need a fix for this problem. So if there is a better fix that you have please post it to lkml. Thanks, Chandru _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
