Modifying MSR has no effect on the stats
Mahmood N <[email protected]>
| Newsgroups | gmane.linux.oprofile |
|---|---|
| Message-ID | <[email protected]> |
Hi,According to the BKDG of 15h family, the following MSR controls the hardware prefetcher at L1. MSRC001_1022 Data Cache Configuration (DC_CFG) Bits /////// Description 63:16 /////// Reserved. 15 /////// DisPfHwForSw. Read-write. Reset: 0. 1=Disable hardware prefetches for software prefetches. 14 /////// Reserved. 13 /////// DisHwPf. Read-write. Reset: 0. 1=Disable the DC hardware prefetcher. BIOS: See 2.3.3 [Using L2 Cache as General Storage During Boot]. 12:10 /////// Reserved. 9:5 /////// Reserved. 4 /////// DisSpecTlbRld. Read-write. Reset: 0. 1=Disable speculative TLB reloads. BIOS: See 2.3.3 [UsingL2 Cache as General Storage During Boot]. 3:0 /////// Reserved. Problem is when I disable it (setting 13th to 1), the stats regarding the prefetcher remains non-zero! [root@tiger exe]# rdmsr -a -x -0 0xc0011022 0000000000000000 <32 LINES FOR 32 CORES> [root@tiger exe]# wrmsr -a 0xc0011022 0x2000 [root@tiger exe]# rdmsr -a -x -0 0xc0011022 0000000000002000 <32 LINES FOR 32 CORES>[root@tiger exe]# ocount -e CPU_CLK_UNHALTED,RETIRED_INSTRUCTIONS,DATA_CACHE_ACCESSES,DATA_CACHE_MISSES,DATA_PREFETCHER,PREFETCH_INSTRUCTIONS_DISPATCHED,REQUESTS_TO_L2,L2_CACHE_MISS,L2_PREFETCHER_TRIGGER ./bzip2_base.amd64-m64-gcc44-nn Events were actively counted for 36.0 seconds. Event counts (scaled) for /home/mahmood/spec-cpu2006-x86_64/benchspec/CPU2006/401.bzip2/exe/bzip2_base.amd64-m64-gcc44-nn: Event Count % time counted CPU_CLK_UNHALTED 107,340,837,082 55.55 DATA_CACHE_ACCESSES 55,973,655,378 66.66 DATA_CACHE_MISSES 1,720,001,433 66.65 DATA_PREFETCHER 1,081,055,468 66.66 L2_CACHE_MISS 265,881,095 66.67 L2_PREFETCHER_TRIGGER 261,646,431 55.57 PREFETCH_INSTRUCTIONS_DISPATCHED 397,803 66.68 REQUESTS_TO_L2 2,796,342,677 44.45 RETIRED_INSTRUCTIONS 108,589,570,814 55.57 Isn't that strange? Regards, Mahmood ------------------------------------------------------------------------------ _______________________________________________ oprofile-list mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/oprofile-list