On Sun, 23 Jan 2005, Jay Roplekar wrote: > I am not sure this is a fixed problem in 2.6.11-rc2 based on my read of the > changelog, hence this email. Here is the summary: > > 1. I started with vanilla 2.6.10 where I replaced ieee1394 drivers from > trunk > rev 1251 patched in. My kernel is tainted due to ndiswrapper that loads > windows drivers for my wireless PCI card.
Thanks for identifying that. > One out of 4 times I actually > booted 2.6.10 and manually brought up wlan0 I got 'reboot needed etc > messages' . Please note that using similar approach in 2.6.8 does not cause > this issue. Following is the error in /var/log/messages ( I did not paste > everything to be brief): > > Jan 22 08:26:58 localhost kernel: Bad page state at prep_new_page (in process > 'net_applet', page c1323a00) > Jan 22 08:26:58 localhost kernel: flags:0x20000004 mapping:00000000 > mapcount:1 > count:1 This is a different case from any I've seen reported before: we've seen several "mapcount:1 count:0" reports, but here you have "mapcount:1 count:1" which is evidence plus confirmation that the page is really in use. Yet prep_new_page is being called while (re!)allocating this page that's already in use. Sounds like a disagreement between page counts and the buddy system. But the most obvious cause of that, misuse of a high-order page by freeing a lower-order page from within it, should hit the BUG_ON in put_page_testzero before ever getting this far. So, sorry, I've no idea. > Jan 22 08:26:58 localhost kernel: Backtrace: > Jan 22 08:26:58 localhost kernel: [dump_stack+30/32] dump_stack+0x1e/0x20 > Jan 22 08:26:58 localhost kernel: [<c0103cde>] dump_stack+0x1e/0x20 > Jan 22 08:26:58 localhost kernel: [bad_page+117/176] bad_page+0x75/0xb0 > Jan 22 08:26:58 localhost kernel: [<c013c1b5>] bad_page+0x75/0xb0 > Jan 22 08:26:58 localhost kernel: [prep_new_page+40/112] > prep_new_page+0x28/0x70 > Jan 22 08:26:58 localhost kernel: [<c013c4d8>] prep_new_page+0x28/0x70 You've edited out the full stacktrace for brevity; and were probably quite right to do so, the state of this page is not likely to have anything to do with the process it's now being allocated to. > ##### > Jan 22 08:26:58 localhost kernel: ------------[ cut here ]------------ > Jan 22 08:26:58 localhost kernel: kernel BUG at mm/rmap.c:483! And this is just a consequence of bad_page resetting mapcount from 1 to 0 (well, from 0 to -1 if you delve into how those counts are implemented): just further confirmation that the reallocated page was really in use. > 2. I patched in Hugh's patch to 2.6.10 and recompiled. At reboot I ran > memtest86 v 1.26, 3 times without any error. Then rebooting in 2.6.10 and > doing ifup wlan0 gave me system freeze and unfortunately nothing in the log. > Since then I have not seen the same error again after 3 reboots and 2-3 > cold > boots followed by ifup. I also tried cycles of ifdown and ifup without any > errors. Both that patch and memtest86 are good responses, though I doubt my patch will actually help us much in your case. > 3. I am not sure if I should post my whole config here hence I just pasting > DRM related entries here in reference to your original email to Jose`. I > have VIA motherboard and a matrox agp card, [FWIW most of the config is same > as for 2.6.8 kernel that did not show the rmap sympton] > > CONFIG_AGP_VIA=m > CONFIG_DRM=y > CONFIG_DRM_MGA=m DRM again, hmm, thanks, yes, useful info. > I will be glad to provide any other info needed. You may bcc to my email if > this is better discussed off the list. [Although I will anxiously check > lkml.org everyday or use RSS feed]. I am not subsribed as We are not > worthy :-) Your worthiness is manifest, in all you've said, and left unsaid. All I can say for now is, please let us know if you get more such traces. Thanks, Hugh - 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/
