Re: 2.6.14 kswapd eating too much CPU

[Marcelo Tosatti <marcelo.tosatti@cyclades.com>]

On Tue, Dec 06, 2005 at 01:10:06AM +0100, Jan Kasprzak wrote:
> Marcelo Tosatti wrote:
> : I wonder why prune_icache() does not move inodes with positive i_count
> : to inode_inuse list, letting iput() take care of moving to unused
> : once the count reaches zero.
> : 
> :                 inode = list_entry(inode_unused.prev, struct inode, i_list);
> :                 if (inode->i_state || atomic_read(&inode->i_count)) {
> :                         list_move(&inode->i_list, &inode_unused);
> :                         continue;
> :                 }
> : 
> : Couldnt it be 
> : 			list_move(&inode->i_list, &inode_inuse);
> : 
> : ?
> 
> 	Hmm, this code is indeed strange. Why does it move the inode
> to the inode_unused list, when the inode has in fact been _found_ while
> scanning the inode_unused list? 

It just moves to the head of the list, for later scanning.

> And how can an inode with positive ->i_count end up on the
> inode_unused list?

Such inodes only end up in the unused list during superblock
shutdown, so they should not be a problem actually (my bad).