On Mon, 17 Dec 2007 12:13:22 +0000 richard <[EMAIL PROTECTED]> wrote:
> fix lockup in when calling drop_caches > > calling /proc/sys/vm/drop_caches can hang due to a AB/BA lock dependency > between j_list_lock and the inode_lock. This patch moves the redirtying > of the buffer head out > from under the j_list_lock. > > based on a suggestion by Andrew Morton. > Oh boy. Do we really want to add all this stuff to JBD just for drop_caches which is a silly root-only broken-in-22-other-ways thing? Michael, might your convert-inode-lists-to-tree patches eliminate the need for taking inode_lock in drop_pagecache_sb()? Probably not, as it uses an rbtree. It would have been possible if it was using a radix-tree, I suspect.. > -void __journal_unfile_buffer(struct journal_head *jh) > +void __journal_unfile_buffer(struct journal_head *jh, > + struct buffer_head **dirty_bh) > { > - __journal_temp_unlink_buffer(jh); > + __journal_temp_unlink_buffer(jh, dirty_bh); > jh->b_transaction = NULL; > } I suspect the code would end up simpler if __journal_unfile_buffer() were to take an additional ref on the bh which it placed at *dirty_bh. Callers of __journal_unfile_buffer() could then call void handle_dirty_bh(struct buffer_head *bh) { if (bh) { jbd_mark_buffer_dirty(bh); put_bh(bh); } } ? -- 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/