Sebastian, On Thu, Dec 24, 2020 at 12:30:35PM +0100, Sebastian Andrzej Siewior wrote: > On 2020-12-24 00:51:58 [+0300], Vitaly Chikunov wrote: > > Add guard call to allocate the memory before calling get_thread to > > prevent memory failures (LZMA_MEM_ERROR). > > > > This would make simple `xz -T0' more robust on 32-bit architectures. > > > > Rationale: simple `-T0' is hard to use portably in scripts on different > > platforms, because there is always different amount of RAM and CPU, > > causing unexpected "xz: Cannot allocate memory" errors. > > Could you please say how much CPUs, memory you have and what command > line you have used?
For example, AND EPYC system is with 32 CPUs (by nproc output) and >200G memory*. It have no problem using `-T0` in 64-bit mode, but the same system in PER_LINUX32 personality have 4 GiB memory limit (due to 32-bit address space), thus, having 32 CPU and just 4GiB memory produces memory allocation failure. You can reproduce the problem even on 64-bit Linux system if you (having 32 cpu) impose 4GiB memory limit by some means, for example like this: altair$ nproc 32 altair$ ulimit -Sv 4000000 altair$ head -555444333c /dev/zero | xz -T0 - > /dev/null xz: (stdin): Cannot allocate memory After this patch is applied (test in linux32 on the same system): i586:xz-5.2.5$ head -555444333c /dev/zero | src/xz/xz -T0 - > /dev/null i586:xz-5.2.5$ Thanks, __ * We use such system for our RPM build/re-build and testing process in our Linux distribution. But the same scripts (called 'gear') are used by each maintainer to build packages locally. After we added simple `-T0` to our xz run (to speed up .txz creation) we are forced to revert that usage next day, because many packages had rebuild failures on 32-bit systems (we have ARM and i586). > > > Signed-off-by: Vitaly Chikunov <v...@altlinux.org> > > Sebastian
