Hi Mel,
I discovered recently that a kernel built with ppc64_defconfig no longer
boots on legacy iSeries. It did in 2.6.23. I bisected down the commit
d9c2340052278d8eb2ffb16b0484f8f794def4de ("Do not depend on MAX_ORDER
when grouping pages by mobility") which fails while its parent is ok.
Also, an iseries_defconfig kernel will boot. The reason it seem is
because on PowerPC 64 with CONFIG_HUGETLB_PAGE, HPAGE_SHIFT is not
constant and its value is determined at runtime early.For legacy iSeries HPAGE_SHIFT remains 0 which means that HUGETLB_PAGE_ORDER becomes -PAGE_SHIFT and things degenerate badly. I can enable CONFIG_HUGETLB_PAGE_SIZE_VARIABLE for PowerPC 64, but I still need to know a good value for HPAGE_SHIFT. Do you have a suggestion? Is there a better way to fix this problem? There are places in the PowerPC code that assume that HPAGE_SHIFT == 0 means that we have no huge pages. -- Cheers, Stephen Rothwell [EMAIL PROTECTED] http://www.canb.auug.org.au/~sfr/
pgpKphbLQPNxP.pgp
Description: PGP signature
_______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
