Thanks David. This indeed gave more samples. Do you know why the symbol [k] 0xffffffff81043fea occured so often? As shown in the pasted result, both "swapper" and "perf" had this symbol. And if I "perf record dd if=/dev/zero of=/dev/null" or "perf record ping", they all showed this symbol. I pasted these results in the end of this email. I guess my real concern is the symbols cannot be mapped into meaningful function names. These symbols cannot be found in either /proc/kallsyms nor the vmlinux I built from the kernel source tree. Any idea? Thanks.
result of sudo perf record -a -- sleep 1 # Samples: 104 of event 'cycles' # Event count (approx.): 61197061 # # Overhead Command Shared Object Symbol # ........ ............... .......................... ...... # 47.49% swapper [kernel.kallsyms] [k] 0xffffffff81043fea 11.78% chromium-browse [kernel.kallsyms] [k] 0xffffffff81095950 11.46% chromium-browse chromium-browser [.] 0x000000000160d0a6 4.07% chromium-browse perf-5594.map [.] 0x00000bb86b1cb70a 4.07% perf [kernel.kallsyms] [k] 0xffffffff81043fea 2.38% sleep perf [.] 0x00000000000459da 2.29% sleep [kernel.kallsyms] [k] 0xffffffff813548c3 2.05% java perf-3109.map [.] 0x00007f84d5206071 2.05% indicator-cpufr libgobject-2.0.so.0.3200.3 [.] 0x0000000000031787 2.05% compiz libc-2.15.so [.] 0x0000000000082fa6 2.02% chromium-browse libflashplayer.so [.] 0x0000000000803fe7 1.88% java libglib-2.0.so.0.3200.3 [.] 0x0000000000045619 1.72% chromium-browse libglib-2.0.so.0.3200.3 [.] 0x0000000000019930 1.64% chromium-browse libpthread-2.15.so [.] 0x000000000000cd60 1.02% Xorg [kernel.kallsyms] [k] 0xffffffff81044c1d 0.62% swapper [i915] [k] 0x0000000000000ce5 0.62% Xorg [i915] [k] 0x0000000000018a80 0.51% Xorg Xorg [.] 0x000000000013a619 0.29% kworker/0:1 [kernel.kallsyms] [k] 0xffffffff81096afc result of sudo perf record dd if=/dev/zero of=/dev/null: # Overhead Command Shared Object Symbol # ........ ....... ................. ...... # 76.89% dd [kernel.kallsyms] [k] 0xffffffff81043fea 13.91% dd libc-2.15.so [.] 0x000000000014815f 9.21% dd dd [.] 0x0000000000004889 result of sudo perf record ping 10.0.0.1: # Overhead Command Shared Object Symbol # ........ ....... ................. ...... # 64.59% ping ld-2.15.so [.] 0x00000000000188d2 35.41% ping [kernel.kallsyms] [k] 0xffffffff81043fea -- Regards, Chao Xu -- To unsubscribe from this list: send the line "unsubscribe linux-perf-users" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html