On Wed, 2010-01-06 at 13:52 -0500, Trond Myklebust wrote: > On Wed, 2010-01-06 at 19:37 +0100, Peter Zijlstra wrote: > > On Wed, 2010-01-06 at 13:26 -0500, Trond Myklebust wrote: > > > OK. It looks as if the only key to finding out how many unstable writes > > > we have is to use global_page_state(NR_UNSTABLE_NFS), so we can't > > > specifically target our own backing-dev. > > > > Would be a simple matter of splitting BDI_UNSTABLE out from > > BDI_RECLAIMABLE, no? > > > > Something like > > OK. How about if we also add in a bdi->capabilities flag to tell that we > might have BDI_UNSTABLE? That would allow us to avoid the potentially > expensive extra calls to bdi_stat() and bdi_stat_sum() for the non-nfs > case? The bdi_stat_sum() in the error limit is basically the only such expensive op, but I suspect we might hit that more than enough. So sure that sounds like a plan. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
