On Mon, Sep 26, 2016 at 05:58:02PM +0200, David Sterba wrote: > On Fri, Sep 23, 2016 at 02:22:53PM -0700, Omar Sandoval wrote: > > On Fri, Sep 23, 2016 at 09:52:01AM -0700, Omar Sandoval wrote: > > > On Fri, Sep 23, 2016 at 11:27:27AM +0200, David Sterba wrote: > > > > On Thu, Sep 22, 2016 at 05:24:25PM -0700, Omar Sandoval wrote: > > > > > From: Omar Sandoval <osan...@fb.com> > > > > > > > > > > test_find_delalloc() allocates 256 MB worth of pages. That's all of > > > > > the > > > > > RAM that my MIPS emulator has, so it ends up panicking after it OOM > > > > > kills everything. We don't actually need to use that much for this > > > > > test. > > > > > > > > I'm not sure we should limit it that way as more bytes can give it more > > > > stress. Can we do it somehow dynamically ? Like start with 256M and fall > > > > back to the numbers you've used. > > > > > > > > Or maybe start from the low bound and allocate until it fails with first > > > > ENOMEM. > > > > > > I figured out how to get qemu to do highmem on MIPS, so we can drop this > > > patch. It's reasonable to assume that the sanity tests are running on a > > > machine with a decent amount of memory. > > > > I lied, that didn't fix the problem for me, since these page allocations > > can't use highmem. Anyways, the tests seem to be testing more for logic > > errors manipulating the extent io tree, so just scaling it down > > shouldn't be a huge issue, right? > > > > The problem with relying on ENOMEM for anything is that the OOM killer > > will kick in before we actually get the ENOMEM. I tried adding > > __GFP_NORETRY, which claims that it doesn't invoke the OOM killer, but > > it still did :( > > I think we cannot rely on NORETRY behaviour wrt OOM killer anyway. For > now I'd rather leave out the patch and let people test on machines with > enough memory. Any furhter ideas to make it work on low memory are > welcome but I don't want to block this patchset.
Yeah that's fine, we can come back to this another time. -- Omar -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
