From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 22 Sep 2000 18:11:25 -0500 From: Timur Tabi Subject: kernel BUG at page_alloc.c:85 (iounmap) Message-Id: <20000922230543Z131169-10809+23@kanga.kvack.org> Sender: owner-linux-mm@kvack.org Return-Path: To: Linux Kernel Mailing list , Linux MM mailing list List-ID: I have a driver which calls marks a physical page as PG_Reserved, calls ioremap_nocache() on it, performs a non-destructive memory write, and then calls iounmap(). I have a recurring problem which I can't figure out. After 28 such map/unmap calls, I get an error in page_alloc.c on line 85. This is with 2.4.0-test2. The offending line is in function __free_pages_ok: if (page->buffers) BUG(); My guess is that the page I'm trying to map with iounmap() has a non-zero value of buffers before I map it, but ioremap() doesn't care about that. But when I go to iounmap it, then it checks buffers and complains. Is this correct? And if so, what does 'buffers' do? -- Timur Tabi - ttabi@interactivesi.com Interactive Silicon - http://www.interactivesi.com When replying to a mailing-list message, please don't cc: me, because then I'll just get two copies of the same message. -- 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.eu.org/Linux-MM/