Re: hunting an IO hang
From: Chris Mason <hidden>
Date: 2011-01-17 21:25:30
Excerpts from Linus Torvalds's message of 2011-01-17 13:24:55 -0500:
On Mon, Jan 17, 2011 at 9:40 AM, Chris Mason [off-list ref] wrote:quoted
quoted
quoted
I've reverted 744ed1442757767ffede5008bb13e0805085902e, and d8505dee1a87b8d41b9c4ee1325cd72258226fbc and the run has lasted longer than any runs in the past.Confirmed that reverting these patches makes the problem unreproducible for the many_dd's + fsmark for at least an hour here.After 2+ hours I'm still running with those two commits gone. A I'm confident they are the cause of the crashes. A I also haven't triggered the cfq stalls without them.Ok, so the question is how to proceed from here. I can easily revert them, and since I was planning on doing -rc1 tonight, I probably will. But I promised Chris to delay until tomorrow if he needed time to chase this down, and while it's now apparently chased down, I'll certainly also be open to delaying until tomorrow if somebody has a patch to fix it. So right now my plan is: - I will revert those two later today and then release -rc1 in the evening UNLESS - somebody posts a patch for the problem in the next few hours and Chris/others are willing to give it a good test overnight (or whatever people feel is "sufficient" based on how easily they can trigger the issue), in which case I'd do -rc1 tomorrow (either with the reverts or the patch, depending on how testing works out)
If a patch does come in, I'm happy to test it. Mel had a test that triggered within 1-2 minutes, mine took 30 or so, which means I'd want a 2 hour run to convince myself it was really fixed. But, I'll give Mel's fs_mark + dd workload a try on the buggy kernel. -chris -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>