Wu Fengguang
2009-Jun-09 03:07 UTC
Re: sk_lock: inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage
On Mon, Jun 08, 2009 at 12:55:18PM +0800, KOSAKI Motohiro wrote:> Hi > > > Hi, > > > > This lockdep warning appears when doing stress memory tests over NFS. > > > > page reclaim => nfs_writepage => tcp_sendmsg => lock sk_lock > > > > tcp_close => lock sk_lock => tcp_send_fin => alloc_skb_fclone => page reclaim > > > > Any ideas? > > AFAIK, btrfs has re-dirty hack. > > ------------------------------------------------------------------ > static int btrfs_writepage(struct page *page, struct writeback_control *wbc) > { > struct extent_io_tree *tree; > > > if (current->flags & PF_MEMALLOC) { > redirty_page_for_writepage(wbc, page); > unlock_page(page); > return 0; > } > tree = &BTRFS_I(page->mapping->host)->io_tree; > return extent_write_full_page(tree, page, btrfs_get_extent, wbc); > } > --------------------------------------------------------------- > > PF_MEMALLOC mean caller is try_to_free_pages(). (not normal write nor kswapd)No, kswapd also sets the PF_MEMALLOC flag. It looks like btrfs_writepage() is trying to avoid inefficient page outs at the cost of pinning dirty pages in memory (even when we really want free pages). Thanks, Fengguang> Can''t nfs does similar hack? > > > I''m not net nor nfs expert. perhaps I''m wrong :-) > > > Thanks. > >-- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html
KOSAKI Motohiro
2009-Jun-09 03:15 UTC
Re: sk_lock: inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage
> On Mon, Jun 08, 2009 at 12:55:18PM +0800, KOSAKI Motohiro wrote: > > Hi > > > > > Hi, > > > > > > This lockdep warning appears when doing stress memory tests over NFS. > > > > > > page reclaim => nfs_writepage => tcp_sendmsg => lock sk_lock > > > > > > tcp_close => lock sk_lock => tcp_send_fin => alloc_skb_fclone => page reclaim > > > > > > Any ideas? > > > > AFAIK, btrfs has re-dirty hack. > > > > ------------------------------------------------------------------ > > static int btrfs_writepage(struct page *page, struct writeback_control *wbc) > > { > > struct extent_io_tree *tree; > > > > > > if (current->flags & PF_MEMALLOC) { > > redirty_page_for_writepage(wbc, page); > > unlock_page(page); > > return 0; > > } > > tree = &BTRFS_I(page->mapping->host)->io_tree; > > return extent_write_full_page(tree, page, btrfs_get_extent, wbc); > > } > > --------------------------------------------------------------- > > > > PF_MEMALLOC mean caller is try_to_free_pages(). (not normal write nor kswapd) > > No, kswapd also sets the PF_MEMALLOC flag. It looks like btrfs_writepage() > is trying to avoid inefficient page outs at the cost of pinning dirty > pages in memory (even when we really want free pages).Sorry, I was confused ;) -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html