On Sun, 2010-08-22 at 08:33 +0100, Ian Campbell wrote: > On Sun, 2010-08-22 at 07:57 +0100, Ian Campbell wrote: > > On Sat, 2010-08-21 at 08:48 -0700, Linus Torvalds wrote: > > > On Sat, Aug 21, 2010 at 4:56 AM, Ian Campbell wrote: > > > > > > > > I don't know that they are particularly good tests for this change but I > > > > also ran allmodconfig kernel build and ltp on 2.6.35.3+fixes without > > > > issue. Are there any good mlock heavy workloads? > > > > > > mlock itself isn't very interesting, I think more interesting is > > > testing that the doubly linked list handles all the cases correctly. > > > Something that splits mappings, unmaps partial ones etc etc. Running > > > something like Electric Fence is probably a good idea. > > > > EF_DISABLE_BANNER=1 EF_ALLOW_MALLOC_0=1 LD_PRELOAD=libefence.so.0.0 make > > > > craps out pretty quickly with: > > > > CC init/main.o > > > > ElectricFence Exiting: mprotect() failed: Cannot allocate memory > > make[1]: *** [init/main.o] Error 255 > > make: *** [init] Error 2 > > > > but it does that with 2.6.35.3, 2.6.35.2, 2.6.35.1 and 2.6.35 too so it > > doesn't seem to be breakage relating to any of the stack guard stuff > > I increased the vm.max_map_count sysctl and now things are rolling > along. Will let you know how I get on. So its slow and memory intensive as hell due to efence so my test box is struggling[0] but it has compiled 270+ .o files successfully so I think it's OK from that perspective. I think it'll be quite a while before I can say its passed an allmodconfig under efence though. In the meantime I notice you've committed the patches. Can we get them queued up for stable backports at some point? I appreciate you might want them to bake for a bit longer in 2.6.36-rc first. Greg, we are talking about: 0e8e50e20c837eeec8323bba7dcd25fe5479194c mm: make stack guard page logic use vm_prev pointer 7798330ac8114c731cfab83e634c6ecedaa233d7 mm: make the mlock() stack guard page checks stricter 297c5eee372478fc32fec5fe8eed711eedb13f3d mm: make the vma list be doubly linked Cheers, Ian. [0] It's a 4G x 4 core box which normally does -j16 builds with no swap. Now a -j4 will send it deep into the 16G of swap I added this morning, and even a -j3 is a bit tight. I knew efence was resource intensive but this still surprised me. -- Ian Campbell Who does not love wine, women, and song, Remains a fool his whole life long. -- Johann Heinrich Voss