On Fri, 2007-05-18 at 09:37 +0530, Balbir Singh wrote: >> oops! I wonder if AIM7 creates too many processes and exhausts all >> memory. I've seen a case where during an upgrade of my tetex on my >> laptop, the setup process failed and continued to fork processes >> filling up 4GB of swap.
On Mon, May 21, 2007 at 09:53:34AM -0400, Lee Schermerhorn wrote: > Jumping in late, I just want to note that in our investigations, when > AIM7 gets into this situation [non-responsive system], it's because all > cpus are in reclaim, spinning on an anon_vma spin lock. AIM7 forks [10s > of] thousands of children from a single parent, resultings in thousands > of vmas on the anon_vma list. shrink_inactive_list() must walk this > list twice [page_referenced() and try_to_unmap()] under spin_lock for > each anon page. I wonder how far out RCU'ing the anon_vma lock is. On Mon, May 21, 2007 at 09:53:34AM -0400, Lee Schermerhorn wrote: > [Aside: Just last week, I encountered a similar situation on the > i_mmap_lock for page cache pages running a 1200 user Oracle/OLTP run on > a largish ia64 system. Left the system spitting out "soft lockup" > messages/stack dumps overnight. Still spitting the next day, so I > decided to reboot.] > I have a patch that turns the anon_vma lock into a reader/writer lock > that alleviates the problem somewhat, but with 10s of thousands of vmas > on the lists, system still can't swap enough memory fast enough to > recover. Oh dear. Some algorithmic voodoo like virtually clustered scanning may be in order in addition to anon_vma lock RCU'ing/etc. On Mon, May 21, 2007 at 09:53:34AM -0400, Lee Schermerhorn wrote: > We've run some AIM7 tests with Rik's "split lru list" patch, both with > and without the anon_vma reader/writer lock patch. We'll be posting > results later this week. Quick summary: with Rik's patch, AIM > performance tanks earlier, as the system starts swapping earlier. > However, system remains responsive to shell input. More into to follow. I'm not sure where policy comes into this. -- wli - 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/
