On Fri, 28 Sep 2007 15:16:11 -0400 Trond Myklebust <trond.myklebust@xxxxxxxxxx> wrote: > On Fri, 2007-09-28 at 11:49 -0700, Andrew Morton wrote: > > On Fri, 28 Sep 2007 13:00:53 -0400 Trond Myklebust <trond.myklebust@xxxxxxxxxx> wrote: > > > 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) > > Looking back, they were getting caught up in > balance_dirty_pages_ratelimited() and friends. See the attached > example... that one is nfs-on-loopback, which is a special case, isn't it? NFS on loopback used to hang, but then we fixed it. It looks like we broke it again sometime in the intervening four years or so. _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
