On Fri, 28 Sep 2007 13:00:53 -0400 Trond Myklebust <[EMAIL PROTECTED]> 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) - 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/
