Hi, On Thu, 31 Jan 2013 09:25:49 -0700, David Ahern wrote: > Hi > > On 1/31/13 2:08 AM, [email protected] wrote: >> From: [email protected] >> >> This patch depends on a prev patch: https://lkml.org/lkml/2013/1/29/47 >> >> If the engineers want to analyze the direct io behavior of some applications >> without source code, perf tools with some appropriate tracepoints events in >> the >> VFS subsystem are excellent choice. >> >> Many database systems use their own page cache subsystems and use the direct >> IO >> to access the disks. Sometimes, the system engineers need to know the misses >> rate >> of the database system's page cache. This requirements can be satisfied by >> recording >> the database's file access behavior through the way of direct IO. So, we use >> 2 >> tracepoint events to record the system wide's direct IO behavior. The 2 >> tracepoint >> events are: >> 1) vfs:direct_io_read >> 2) vfs:direct_io_write >> they were introduced by the patch: https://lkml.org/lkml/2013/1/29/47 >> The script direct-io.py are introduced by this patch can record the 2 >> tracepoint >> events, analyse the sample data, and give a concise report. > > What does this option provide that the I/O accounting with taskstats > (e.g., iotop) does not provide?
Maybe it's better to put this into 'blktrace' tool once the TPs are accepted. Thanks, Namhyung -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
