> Page faults, CPU cache misses. XFS has a significantly large icache > and dcache footprint than ext4, so those are the likely causes I have a query. Will page fault, cache misses etc will increase the %user CPU utilization or %system CPU utilization. I thought it will affect the %system and not %user CPU usage? %user - Percentage of CPU utilization that occurred while executing at the user level (application). %system - Percentage of CPU utilization that occurred while executing at the system level (kernel). On Mon, Feb 18, 2013 at 2:55 AM, Dave Chinner <david@xxxxxxxxxxxxx> wrote: > On Sun, Feb 17, 2013 at 09:20:46PM +0530, Subranshu Patel wrote: >> I created 2 filesystem on my system (RHEL 6.3, kernel 2.6.32) - XFS >> and EXT4 and mounted them. >> >> On both the filesystem I executed a program which performed the following: >> - Create large number of directories >> - Removing all the directories >> >> During the execution of the program, I monitored the %user and %system >> CPU usage (using sar command) >> >> For EXT4 the %user was 1% and %system was 21% >> For XFS the %user was 20% and %system was 52% >> >> But I am not able to understand %user consumption, since %user reports >> the CPU usage of the user level (application), shouldn't it be the >> same for both EXT4 and XFS? > > Perf is your friend. > >> What are the factors that decide the %user component keeping in mind >> that only the filesystem is different? > > Page faults, CPU cache misses. XFS has a significantly large icache > and dcache footprint than ext4, so those are the likely causes. > > Cheers, > > Dave. > -- > Dave Chinner > david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
