THanks for the report but this belongs to the cygwin ML. I'm redirecting this here.
Corinna On Apr 10 18:36, Achim Gratz wrote: > > As briefly discussed on IRC I've got a new Server 2016 blade with 2 > sockets × 8 cores × 2 HT =32 logical processors and Cygwin spews errors > for processor ID 16 and up (also top doesn't quite work, which likely > has the same reason, although the code path may be unrelated to the > /proc/cpuinfo bug described here). > > --8<---------------cut here---------------start------------->8--- > 64bit (166)~ > cat /proc/cpuinfo > 0 [main] cat 10068 format_proc_cpuinfo: SetThreadGroupAffinity(10000,0 > (10/16)) failed Win32 error 87 > 209 [main] cat 10068 format_proc_cpuinfo: SetThreadGroupAffinity(20000,0 > (11/17)) failed Win32 error 87 > 913 [main] cat 10068 format_proc_cpuinfo: SetThreadGroupAffinity(40000,0 > (12/18)) failed Win32 error 87 > 1047 [main] cat 10068 format_proc_cpuinfo: SetThreadGroupAffinity(80000,0 > (13/19)) failed Win32 error 87 > 1151 [main] cat 10068 format_proc_cpuinfo: SetThreadGroupAffinity(100000,0 > (14/20)) failed Win32 error 87 > 1266 [main] cat 10068 format_proc_cpuinfo: SetThreadGroupAffinity(200000,0 > (15/21)) failed Win32 error 87 > 1383 [main] cat 10068 format_proc_cpuinfo: SetThreadGroupAffinity(400000,0 > (16/22)) failed Win32 error 87 > 1479 [main] cat 10068 format_proc_cpuinfo: SetThreadGroupAffinity(800000,0 > (17/23)) failed Win32 error 87 > 1573 [main] cat 10068 format_proc_cpuinfo: > SetThreadGroupAffinity(1000000,0 (18/24)) failed Win32 error 87 > 1675 [main] cat 10068 format_proc_cpuinfo: > SetThreadGroupAffinity(2000000,0 (19/25)) failed Win32 error 87 > 1806 [main] cat 10068 format_proc_cpuinfo: > SetThreadGroupAffinity(4000000,0 (1A/26)) failed Win32 error 87 > 1888 [main] cat 10068 format_proc_cpuinfo: > SetThreadGroupAffinity(8000000,0 (1B/27)) failed Win32 error 87 > 1971 [main] cat 10068 format_proc_cpuinfo: > SetThreadGroupAffinity(10000000,0 (1C/28)) failed Win32 error 87 > 2069 [main] cat 10068 format_proc_cpuinfo: > SetThreadGroupAffinity(20000000,0 (1D/29)) failed Win32 error 87 > 2154 [main] cat 10068 format_proc_cpuinfo: > SetThreadGroupAffinity(40000000,0 (1E/30)) failed Win32 error 87 > 2247 [main] cat 10068 format_proc_cpuinfo: > SetThreadGroupAffinity(80000000,0 (1F/31)) failed Win32 error 87 > --8<---------------cut here---------------end--------------->8--- > > It turns out this is related to processor groups and some changes that > probably weren't even in the making when the Cygwin code was written. > These changes were opt-in patches until 2008R2, but are now the default > in 2016: > > https://blogs.msdn.microsoft.com/saponsqlserver/2011/10/08/uneven-windows-processor-groups/ > > The BIOS on that server does something rather peculiar (it does make > sense in a way, but Cygwin clearly didn't expect it): > > https://support.hpe.com/hpsc/doc/public/display?sp4ts.oid=7271227&docId=emr_na-c04650594&docLocale=en_US > > This results in Windows coming up with two 64 core processor groups that > have 16 active logical processors each: > > --8<---------------cut here---------------start------------->8--- > (gdb) print plpi > $1 = (PSYSTEM_LOGICAL_PROCESSOR_INFORMATION_EX) 0x600008020 > (gdb) print *plpi > $2 = {Relationship = RelationGroup, Size = 128, {Processor = {Flags = 2 > '\002', Reserved = "\000\002", '\000' <repeats 18 times>, GroupCount = 0, > GroupMask = {{Mask = 4160, Group = 0, Reserved = {0, 0, 0}}}}, NumaNode > = {NodeNumber = 131074, Reserved = '\000' <repeats 19 times>, > GroupMask = {Mask = 4160, Group = 0, Reserved = {0, 0, 0}}}, Cache = > {Level = 2 '\002', Associativity = 0 '\000', LineSize = 2, CacheSize = 0, > Type = CacheUnified, Reserved = '\000' <repeats 12 times>, > "@\020\000\000\000\000\000", GroupMask = {Mask = 0, Group = 0, Reserved = {0, > 0, > 0}}}, Group = {MaximumGroupCount = 2, ActiveGroupCount = 2, > Reserved = '\000' <repeats 19 times>, GroupInfo = {{ > MaximumProcessorCount = 64 '@', ActiveProcessorCount = 16 '\020', > Reserved = '\000' <repeats 37 times>, ActiveProcessorMask = 65535}}}}} > --8<---------------cut here---------------end--------------->8--- > > I've confirmed that the error message is not printed if I manually > correct the information for processor ID 17 as follows: > > --8<---------------cut here---------------start------------->8--- > (gdb) print affinity > > > $2 = {Mask = 131072, Group = 0, Reserved = {0, 0, 0}} > > > (gdb) set affinity.Mask=2 > > > (gdb) set affinity.Group=1 > --8<---------------cut here---------------end--------------->8--- > > However, the same or possibly even stranger processor group setups can > be created using boot options that force different organizations of > processor groups. There is an option to force a seperate processor > group for each NUMA node and another one to force a specific number of > groups. The upshot is that even the first processor groups may not have > the maximum number of processors present, so you need to check the > number of active processors instead. I couldn't find out if the > processor mask is still guaranteed to be filled from the LSB contigously > or whether one can rely on only the last group to have less than the > first few. It seems more prudent to check the group specific > ActiveProcessorMask, although that significantly complicates the code. > I don't think Windows can currently switch CPU online/offline when > booted. > > > As an aside, the cache size is reported as 256kiB (not just for this > processor, but also for a Celeron 1037U on another machine), which seems > to be the L2 cache for a single hardware core on these architectures. > Linux now reports L3 cache sizes (and possibly L4 if present) for these > (20MiB and 2MiB per socket respectively). > > > Regards, > Achim. > -- > +<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+ > > Factory and User Sound Singles for Waldorf Blofeld: > http://Synth.Stromeko.net/Downloads.html#WaldorfSounds -- Corinna Vinschen Please, send mails regarding Cygwin to Cygwin Maintainer cygwin AT cygwin DOT com Red Hat
signature.asc
Description: PGP signature
