On Friday, June 1, 2007 6:05:39 Venki Pallipadi wrote: > On Fri, Jun 01, 2007 at 02:41:57PM -0700, Jesse Barnes wrote: > > On Friday, June 1, 2007 2:19:43 Andi Kleen wrote: > > > And normally the MTRRs win, don't they (if I remember the table > > > correctly) So if the MTRR says UC and PAT disagrees it might not > > > actually help > > > > I just checked, yes the MTRRs win for UC types. But it sounds like the > > cases we're talking about are actually situations where there's no MTRR > > coverage, so the default type is used. The manual doesn't specifically > > call out how memory using the default type interacts with PAT, but it may > > well be that it stays uncached if the default type is uncached. Again > > that argues for fixing the MTRR mapping problem in some way. > > I feel, having a silent/transparent workaround is not a good idea. With > that chances are BIOS bug will go unnoticed (having an error message in > dmesg may not get noticed either). Probably we should just panic at boot > with a > detailed message about the e820 mtrr discrepancy (which can be logged as > a BUG to BIOS provider) and suggest a temporary workaround of "mem=___".
That might be best, short of actually fixing the MTRRs... Jesse - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
