On 4/24/15 7:31 AM, Yunlong Song wrote:
Now we are profiling the performance of ext4 and f2fs on an eMMC card with iozone, we find a case that ext4 is better than f2fs in random write under the test of "iozone -s 262144 -r 64 -i 0 -i 2". We want to analyze the I/O delay of the two file systems. We have got a conclusion that 1% of sys_write takes up 60% time of the overall sys_write (262144/64=4096). We want to find out the call stack during this specific 1% sys_write. Our idea is to record the stack in a certain time period and since the specific 1% case takes up 60% time, the total number of records of its stack should also takes up 60% of the total records, then we can recognize those stacks and figure out what the I/O stack of f2fs is doing in the 1% case.
And to address this specific profiling problem have you tried: perf trace record -- iozone ... perf trace -i perf.data -S -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
