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| author | Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> | 2015-04-14 09:35:57 +0200 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2015-06-10 06:06:29 +0200 |
| commit | cfcb3d80a28380ba027331eb548ba309c4b66559 (patch) | |
| tree | dfdfc88aaa2a101d5136a7d88eeea9325a342677 /arch/powerpc | |
| parent | selftests/powerpc: Add gitignore file for the new DSCR tests (diff) | |
| download | linux-cfcb3d80a28380ba027331eb548ba309c4b66559.tar.xz linux-cfcb3d80a28380ba027331eb548ba309c4b66559.zip | |
powerpc/mm: Add trace point for tracking hash pte fault
This enables us to understand how many hash fault we are taking
when running benchmarks.
For ex:
-bash-4.2# ./perf stat -e powerpc:hash_fault -e page-faults /tmp/ebizzy.ppc64 -S 30 -P -n 1000
...
Performance counter stats for '/tmp/ebizzy.ppc64 -S 30 -P -n 1000':
1,10,04,075 powerpc:hash_fault
1,10,03,429 page-faults
30.865978991 seconds time elapsed
NOTE:
The impact of the tracepoint was not noticeable when running test. It was
within the run-time variance of the test. For ex:
without-patch:
--------------
Performance counter stats for './a.out 3000 300':
643 page-faults # 0.089 M/sec
7.236562 task-clock (msec) # 0.928 CPUs utilized
2,179,213 stalled-cycles-frontend # 0.00% frontend cycles idle
17,174,367 stalled-cycles-backend # 0.00% backend cycles idle
0 context-switches # 0.000 K/sec
0.007794658 seconds time elapsed
And with-patch:
---------------
Performance counter stats for './a.out 3000 300':
643 page-faults # 0.089 M/sec
7.233746 task-clock (msec) # 0.921 CPUs utilized
0 context-switches # 0.000 K/sec
0.007854876 seconds time elapsed
Performance counter stats for './a.out 3000 300':
643 page-faults # 0.087 M/sec
649 powerpc:hash_fault # 0.087 M/sec
7.430376 task-clock (msec) # 0.938 CPUs utilized
2,347,174 stalled-cycles-frontend # 0.00% frontend cycles idle
17,524,282 stalled-cycles-backend # 0.00% backend cycles idle
0 context-switches # 0.000 K/sec
0.007920284 seconds time elapsed
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/include/asm/trace.h | 20 | ||||
| -rw-r--r-- | arch/powerpc/mm/hash_utils_64.c | 2 |
2 files changed, 22 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/trace.h b/arch/powerpc/include/asm/trace.h index c15da6073cb8..8e86b48d0369 100644 --- a/arch/powerpc/include/asm/trace.h +++ b/arch/powerpc/include/asm/trace.h @@ -144,6 +144,26 @@ TRACE_EVENT_FN(opal_exit, ); #endif +TRACE_EVENT(hash_fault, + + TP_PROTO(unsigned long addr, unsigned long access, unsigned long trap), + TP_ARGS(addr, access, trap), + TP_STRUCT__entry( + __field(unsigned long, addr) + __field(unsigned long, access) + __field(unsigned long, trap) + ), + + TP_fast_assign( + __entry->addr = addr; + __entry->access = access; + __entry->trap = trap; + ), + + TP_printk("hash fault with addr 0x%lx and access = 0x%lx trap = 0x%lx", + __entry->addr, __entry->access, __entry->trap) +); + #endif /* _TRACE_POWERPC_H */ #undef TRACE_INCLUDE_PATH diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c index a04ca922f0db..5ec987f65b2c 100644 --- a/arch/powerpc/mm/hash_utils_64.c +++ b/arch/powerpc/mm/hash_utils_64.c @@ -57,6 +57,7 @@ #include <asm/fadump.h> #include <asm/firmware.h> #include <asm/tm.h> +#include <asm/trace.h> #ifdef DEBUG #define DBG(fmt...) udbg_printf(fmt) @@ -1004,6 +1005,7 @@ int hash_page_mm(struct mm_struct *mm, unsigned long ea, DBG_LOW("hash_page(ea=%016lx, access=%lx, trap=%lx\n", ea, access, trap); + trace_hash_fault(ea, access, trap); /* Get region & vsid */ switch (REGION_ID(ea)) { |