On Mon, Jun 11 2007, Andrew Morton wrote: > On Mon, 11 Jun 2007 21:59:15 GMT > Linux Kernel Mailing List <linux-kernel@vger.kernel.org> wrote: > > > Gitweb: > > http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=20d698db67059a63d217030dfd02872cb5f88dfb > > Commit: 20d698db67059a63d217030dfd02872cb5f88dfb > > Parent: 17374ff1aa9ce2a0597416a16729474b538af443 > > Author: Jens Axboe <[EMAIL PROTECTED]> > > AuthorDate: Tue Jun 5 11:05:11 2007 +0200 > > Committer: Jens Axboe <[EMAIL PROTECTED]> > > CommitDate: Fri Jun 8 08:33:59 2007 +0200 > > > > splice: move balance_dirty_pages_ratelimited() outside of splice actor > > > > I've seen inode related deadlocks, so move this call outside of the > > actor itself, which may hold the inode lock. > > > > eh? If the pipe_to_file() caller holds inode_lock, our problems are large. > > I doubt if that's true, so what problem is this patch really fixing??
I can repeatedly lock up balance_dirty_pages() if it's called inside the double lock of splice_from_pipe(). I'll fire up the test box and reproduce, then post the backtraces. > > --- > > fs/splice.c | 3 ++- > > 1 files changed, 2 insertions(+), 1 deletions(-) > > > > diff --git a/fs/splice.c b/fs/splice.c > > index b78a7f0..6349d31 100644 > > --- a/fs/splice.c > > +++ b/fs/splice.c > > @@ -652,7 +652,6 @@ find_page: > > * accessed, we are now done! > > */ > > mark_page_accessed(page); > > - balance_dirty_pages_ratelimited(mapping); > > out: > > page_cache_release(page); > > unlock_page(page); > > @@ -823,6 +822,7 @@ generic_file_splice_write_nolock(struct pipe_inode_info > > *pipe, struct file *out, > > if (err) > > ret = err; > > } > > + balance_dirty_pages_ratelimited(mapping); > > } > > > > return ret; > > @@ -876,6 +876,7 @@ generic_file_splice_write(struct pipe_inode_info *pipe, > > struct file *out, > > if (err) > > ret = err; > > } > > + balance_dirty_pages_ratelimited(mapping); > > } > > > > balance_dirty_pages_ratelimited() is supposed to be called > once-per-dirtied-page. This caller can dirty an arbitrarily large amount > of memory and hence should use balance_dirty_pages_ratelimited_nr(). > > As things stand, a large splice() could potentially cause the dirty limits > to be exceeded. It's mostly (at most) 16 pages, not an arbitrarily large amount. So I doubt it makes a lot of difference. > btw, can we please arrange to get patches reviewed prior to them being > merged? Sure, I should have posted the series here. Mostly simple stuff though, and others have seen them. -- Jens Axboe - 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/
