On Tue, Jan 30, 2018 at 2:08 PM, Andres Freund <and...@anarazel.de> wrote: >> That bites, although it's probably tolerable if we expect such errors >> only in exceptional situations such as a needed shared library failing >> to load or something. Killing the session when we run out of memory >> during JIT compilation is not very nice at all. Does the LLVM library >> have any useful hooks that we can leverage here, like a hypothetical >> function LLVMProvokeFailureAsSoonAsConvenient()? > > I don't see how that'd help if a memory allocation fails? We can't just > continue in that case? You could arguably have reserve memory pool that > you release in that case and then try to continue, but that seems > awfully fragile.
Well, I'm just asking what the library supports. For example: https://curl.haxx.se/libcurl/c/CURLOPT_PROGRESSFUNCTION.html If you had something like that, you could arrange to safely interrupt the library the next time the progress-function was called. > The ones I looked at just error out. Needing to handle OOM in soft fail > manner isn't actually that common a demand, I guess :/. Bummer. > I mean we could periodically rescan, rescan after sighup, or such? But > that seems like something for later to me. It's not going to be super > common to install new extensions while a lot of sessions are > running. And things will work in that case, the functions just won't get > inlined... Fair enough. >> > Do people feel these should be hidden behind #ifdefs, always present but >> > prevent from being set to a meaningful, or unrestricted? >> >> We shouldn't allow non-superusers to set any GUC that dumps files to >> the data directory or provides an easy to way to crash the server, run >> the machine out of memory, or similar. > > I don't buy the OOM one - there's so so so many of those already... > > The profiling one does dump to ~/.debug/jit/ - it seems a bit annoying > if profiling can only be done by a superuser? Hm :/ The server's ~/.debug/jit? Or are you somehow getting the output to the client? -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
