On Fri, 28 Sep 2007 13:00:53 -0400 Trond Myklebust <trond.myklebust@xxxxxxxxxx> wrote: > On Thu, 2007-09-27 at 23:50 -0700, Andrew Morton wrote: > > > Actually we perhaps could address this at the VFS level in another way. > > Processes which are writing to the dead NFS server will eventually block in > > balance_dirty_pages() once they've exceeded the memory limits and will > > remain blocked until the server wakes up - that's the behaviour we want. > > > > What we _don't_ want to happen is for other processes which are writing to > > other, non-dead devices to get collaterally blocked. We have patches which > > might fix that queued for 2.6.24. Peter? > > Do these patches also cause the memory reclaimers to steer clear of > devices that are congested (and stop waiting on a congested device if > they see that it remains congested for a long period of time)? Most of > the collateral blocking I see tends to happen in memory allocation... > No, they don't attempt to do that, but I suspect they put in place infrastructure which could be used to improve direct-reclaimer latency. In the throttle_vm_writeout() path, at least. Do you know where the stalls are occurring? throttle_vm_writeout(), or via direct calls to congestion_wait() from page_alloc.c and vmscan.c? (running sysrq-w five or ten times will probably be enough to determine this) _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
