Messages in this thread | | | Date | Fri, 27 Dec 2013 17:19:44 -0500 | From | Sasha Levin <> | Subject | Re: [PATCH] mm: dump page when hitting a VM_BUG_ON using VM_BUG_ON_PAGE |
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On 12/27/2013 05:38 AM, Kirill A. Shutemov wrote: > On Thu, Dec 26, 2013 at 10:20:52PM -0500, Sasha Levin wrote: >> Most of the VM_BUG_ON assertions are performed on a page. Usually, when >> one of these assertions fails we'll get a BUG_ON with a call stack and >> the registers. >> >> I've recently noticed based on the requests to add a small piece of code >> that dumps the page to various VM_BUG_ON sites that the page dump is quite >> useful to people debugging issues in mm. >> >> This patch adds a VM_BUG_ON_PAGE(cond, page) which beyond doing what >> VM_BUG_ON() does, also dumps the page before executing the actual BUG_ON. >> >> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> > > I like the idea. One thing I've noticed you have a lot of page flag based > asserts, like: > > VM_BUG_ON_PAGE(PageLRU(page), page); > VM_BUG_ON_PAGE(!PageLocked(page), page); > > What about adding per-page-flag assert macros, like: > > PageNotLRU_assert(page); > PageLocked_assert(page); > > ? This way we will always dump right page on bug. >
Sure, sounds good.
I'll send another patch on top of this one.
Thanks, Sasha
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