Messages in this thread | | | Date | Thu, 28 Dec 2000 10:25:30 -0800 (PST) | From | Linus Torvalds <> | Subject | Re: [PATCH] not sleep while holding a locked page in block_truncate_page |
| |
On Thu, 28 Dec 2000, Marcelo Tosatti wrote: > > If we call mark_buffer_dirty() on an already dirty buffer, we may sleep > waiting for bdflush even if we haven't caused _any_ real disk IO (because > the buffer was already dirty anyway). > > I think it makes more sense if we only call balance_dirty if we actually > caused real disk IO. > > Would you accept a patch to change that situation by making > __mark_buffer_dirty return the old dirty bit value and make > mark_buffer_dirty only sleep on bdflush if we dirtied a clean buffer?
I would actually prefer not having the balance_dirty() in mark_buffer_dirty() at all, and then just potentially adding an explicit balance_dirty to strategic places. There would probably not be that many of those strategic places.
As it stands, this is a bit too subtle for my taste, having people who sleep without really realizing it, and not necessarily really wanting to (not for correctness issues, but for latency issues - that superblock lock can be quite nasty)
Linus
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
| |