On Mon, Jun 22, 2015 at 08:11:14PM +0200, Daniel Wagner wrote: > On 06/22/2015 02:16 PM, Peter Zijlstra wrote: > > Also, since Linus thinks lglocks is a failed locking primitive (which I > > whole > > heartedly agree with, its preempt-disable latencies are an abomination), it > > also converts the global part of fs/locks's usage of lglock over to a > > percpu-rwsem and uses a per-cpu spinlock for the local part. This both > > provides > > another (4th) percpu-rwsem users and removes an lglock user. > > I did a quick lockperf run with these patches on a 4 socket E5-4610 machine. > These microbenches execercise the fs' locks a bit. > > I suspect I got the wrong tree. The patches did not apply cleanly. The > resulting > kernel boots fine and doesn't explode... so far...
Its against tip/master, although I expect the locking/core bits that were sent to Linus earlier today to be the biggest missing piece. All I really did was build a kernel with lockdep enabled and boot + build a kernel to see it didn't go belly up. > The results aren't looking too bad. Though building a kernel with 'make -j200' > was extreme slow. I'll look into it tomorrow. > > https://git.samba.org/jlayton/linux.git/?p=jlayton/lockperf.git;a=summary Sweet, I wasn't aware these existed. I'll go have a play. > posix01 > mean variance sigma max min > 4.1.0 121.9020 27882.5260 166.9806 603.5509 > 0.0063 > percpu-rwsem 185.3981 38474.3836 196.1489 580.6532 > 0.0073 > > > posix02 > mean variance sigma max min > 4.1.0 12.7461 3.1802 1.7833 15.5411 > 8.1018 > percpu-rwsem 16.2341 4.3038 2.0746 19.3271 > 11.1751 > These two seem to hurt, lemme go look at what they do. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in Please read the FAQ at http://www.tux.org/lkml/
