On Tue, Apr 19, 2011 at 12:59 AM, <p...@pocketnix.org> wrote: > On Mon, Apr 18, 2011 at 06:25:44PM -0400, Joe wrote: >> I was trying to run the test file: >> pypy/jit/backend/x86/test/test_rx86_64_auto_encoding.py >> >> and was getting the following traceback: >> http://paste.pocoo.org/show/374129/ >> >> If you look at the comment on line 17, it's trying to allocate much >> more memory than I have. I think it's a total of 21GB, while I only >> have 4GB. I'm using 64bit OpenSuSE 11.4 for my operating system. I >> had the kernel setting overcommit_memory set to 0 (which may be part >> of the problem). >> >> Anyway, after I went into ll2ctypes.py and set far_regions to True, I >> was able to successfully run the original test. I don't think setting >> far_regions to True is the correct solution to the problem, but >> fiddling with kernel settings on my system is not ideal either. What >> would be a better overall solution? >> >> If any clarification is needed let me know, >> Joe > > > your vm.overcommit_ratio should be set to "50" or 50% by default, as > per > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob_plain;f=Documentation/vm/overcommit-accounting;hb=HEAD > this means that any allocations of 6GB will automatically be rejected > as "not sane" and you should receive the ENOMEM error indicating the > kernel cannot satisfy the supplied range > > there are a couple of ways to fix this > > * don't allocate so much ram (did anyone test this before on a 64bit > host on linux)
The reason for this is that we want to test far jumps (exceeding 4G or 2^32 in address space). How can you do it otherwise? > > * change the vm overcommit policy to 1 (allow everything, don't perform > sanity checks) > > * change the overcommit ratio to something that will satisfy the > allocation (20GB/4GB ~= 5x, so a value of 600% or 600 should do it) > > * Make the mapping a rmmap.MAP_PRIVATE and rmmap.PROT_READ only, > depending on what you are testing this may not be useful as indicated > in the linked kernel documentation > > YYMV, first option is safe, 2nd option you may want to double check > the documentation and the values you are passing, the 3rd option is > also safe in that it will allow badly behaved apps to run, not prevent > apps from running > > > to change either of these values use the following: > > * to adjust the allocation policy: > sysctl vm.overcommit_memory=<val> > > * to adjust the ratio: > sysctl vm.overcommit_ratio=<val> > > to print the current values (and save them for restoring them after > you have done tweaking them: > sysctl vm.overcommit_memory > or > sysctl vm.overcommit_ratio > > > Hope this is whats causing the issue > Da_Blitz > _______________________________________________ > pypy-dev@codespeak.net > http://codespeak.net/mailman/listinfo/pypy-dev > _______________________________________________ pypy-dev@codespeak.net http://codespeak.net/mailman/listinfo/pypy-dev
