[ORACLE 性能优化] AWR中CPUS, CORES, SOCKETS

WORKLOAD REPOSITORY report for

DB Name         DB Id    Instance     Inst Num Startup Time    Release     RAC
------------ ----------- ------------ -------- --------------- ----------- ---
SLOB          3521916847 SLOB                1 29-Sep-12 05:27 11.2.0.3.0  NO

Host Name        Platform                         CPUs Cores Sockets Memory(GB)
---------------- -------------------------------- ---- ----- ------- ----------
NNNN             Linux x86 64-bit                   32    16       2      62.87

We all know that E5-2680 is an 8-core part with SMT (Simultaneous Multi-threading) enabled. Further, this was a 2U 2-socket box. So, sure, 2 sockets and a sum of 16 cores. However, with SMT I get 32 “CPUs”. I’ve quoted CPU because they are logical processors.

WORKLOAD REPOSITORY report forDB Name         DB Id    Instance     Inst Num Startup Time    Release     RAC------------ ----------- ------------ -------- --------------- ----------- ---XXXX          1247149781 xxxx1               1 27-Feb-13 11:32 11.2.0.3.0  YESHost Name        Platform                         CPUs Cores Sockets Memory(GB)---------------- -------------------------------- ---- ----- ------- ----------xxxxxxxx.mmmmmm. Linux x86 64-bit                    8     8       2      62.88

The next example is a cut from an old Harpertown Xeon (Xeon 5400) AWR report. Again, we all know the attributes of that CPU. It was pre-QPI, pre-SMT and it had 4 cores. This was a 2-socket box—so no mystery here. AWR is reporting 2 sockets, a sum of 8 cores and since they are simple cores we see 8 “CPUs”.

$ cat  /proc/cpuinfo | egrep 'processor|vendor_id|model name'processor       : 31vendor_id       : AuthenticAMDmodel name      : AMD Opteron(TM) Processor 6272$ head -10 mix_awr_16_8k.16.16WORKLOAD REPOSITORY report forDB Name         DB Id    Instance     Inst Num Startup Time    Release     RAC------------ ----------- ------------ -------- --------------- ----------- ---XXXXXX         501636137 XXXXXX              1 24-Feb-13 12:21 11.2.0.3.0  NOHost Name        Platform                         CPUs Cores Sockets Memory(GB)---------------- -------------------------------- ---- ----- ------- ----------oel63            Linux x86 64-bit                   32    16       2     252.39

The system is, indeed, a 2-socket box. And cpuinfo is properly showing the processor model number (Opteron 6200 family). Take note as well that the tail of cpuinfo output is CPU 31 so the Operating System believes there are 32 “CPUs”. However, AWR is showing 2 sockets, a sum of 16 cores and 32 CPUs. That’s where the mystery arises. See, the Operton 6200 16-core parts (such as the 6272) are a multi-chip module (MCM) consisting of two soldered dies each with 4 “bulldozer modules.” And never forget that AMD does not do multithreading. So that’s 2x2x4 cores in each socket. However, AWR is reporting a sum of 16 cores in the box. Since there are two sockets, AWR should be reporting 2 sockets, a sum of 32 cores and 32 CPUs. Doing so would more accurately follow the convention we grew accustomed to in the pre-Intel QPI days—as was the case above with the Xeon 5400.

base from:http://www.oaktable.net/content/can-oracle-database-release-2-11203-properly-count-cores-no-does-it-matter-all-much-not-real