On Fri, Aug 19, 2016 at 01:03:51PM -0700, Richard Smith wrote: > On Fri, Aug 19, 2016 at 12:58 PM, Joerg Sonnenberger via cfe-commits < > cfe-commits@lists.llvm.org> wrote: > > > On Thu, Aug 18, 2016 at 11:33:49AM -0700, Richard Smith wrote: > > > On Wed, Aug 17, 2016 at 6:35 AM, Joerg Sonnenberger via cfe-commits < > > > cfe-commits@lists.llvm.org> wrote: > > > > > > > On Wed, Aug 17, 2016 at 01:05:08AM -0000, Richard Smith via cfe-commits > > > > wrote: > > > > > Author: rsmith > > > > > Date: Tue Aug 16 20:05:07 2016 > > > > > New Revision: 278882 > > > > > > > > > > URL: http://llvm.org/viewvc/llvm-project?rev=278882&view=rev > > > > > Log: > > > > > If possible, set the stack rlimit to at least 8MiB on cc1 startup, > > and > > > > work > > > > > around a Linux kernel bug where the actual amount of available stack > > may > > > > be a > > > > > *lot* lower than the rlimit. > > > > > > > > Can you please restrict this to Linux? I'm quite opposed to overriding > > > > system default limits, they exist for a reason. > > > > > > > > > No, that wouldn't make any sense. It's not up to the operating system how > > > an application decides to allocate memory (on the heap versus on the > > > stack), and Clang's stack usage isn't going to be significantly lower on > > > other kernels. If some BSD kernel's VM is unable to cope with this, we > > > could spawn a thread with a suitable amount of stack space instead. > > > > This is not about kernel bugs. It is about POLA -- programs are not > > supposed to alter process limits. If GCC does it, it is a GCC bug. > > That's no reason to introduce the same bug here. Using excessive stack > > space due to deep recursion might be a QoI issue, but it is > > fundamentally no different from any other out of memory condition. Those > > kill clang just as easily. > > > Hitting this limit does not imply that memory was exhausted, it instead > means the OS killed a process that was functioning just fine, for no good > reason.
You are allocating too much stack space. There is no difference to heap allocations which are bound by different flags. It is just a different allocation mechanism. Even hitting a 4MB stack space limit on 64bit platforms takes quite a bit -- not even boost does that by default. As such, I hardly find it normal. Joerg _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
