Date: Tue, 02 Oct 2007 21:52:33 +0900 From: NIIMI Satoshi <sa2c@sa2c.net> To: Jeff Roberson <jroberson@chesapeake.net> Cc: freebsd-current@freebsd.org, freebsd-threads@freebsd.org Subject: Re: sched_yield() is very slow when other threads are busy on FreeBSD-current Message-ID: <47023F11.7000604@sa2c.net> In-Reply-To: <20071002011337.Q6669@10.0.0.1> References: <46FD4B09.20006@sa2c.net> <20071002011337.Q6669@10.0.0.1>
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Hi,
Jeff Roberson wrote:
> Can you please try the enclosed patch and tell me if it addresses your
> problem?
I've tested with SCHED_4BSD and SCHED_ULE.
7-CURRENT, SCHED_4BSD, HZ=100:
81.14 real 80.32 user 0.00 sys
80.85 real 80.03 user 0.00 sys
82.37 real 81.54 user 0.00 sys
7-CURRENT, SCHED_4BSD, HZ=1000:
3.06 real 2.84 user 0.00 sys
3.08 real 2.87 user 0.00 sys
3.00 real 2.80 user 0.01 sys
7-CURRENT, SCHED_ULE, HZ=100:
9.03 real 8.93 user 0.00 sys
1.68 real 1.67 user 0.00 sys
9.13 real 9.04 user 0.00 sys
7-CURRENT, SCHED_ULE, HZ=1000:
4.49 real 4.38 user 0.00 sys
4.57 real 4.48 user 0.00 sys
4.78 real 4.67 user 0.01 sys
6.2-RELEASE, SCHED_4BSD, HZ=100:
0.55 real 0.55 user 0.00 sys
0.54 real 0.54 user 0.00 sys
0.60 real 0.60 user 0.00 sys
6.2-RELEASE, SCHED_4BSD, HZ=1000:
0.29 real 0.29 user 0.00 sys
0.27 real 0.26 user 0.00 sys
0.28 real 0.28 user 0.00 sys
I picked up 3 medians of 5 tests since durations are not stable on
SCHED_ULE.
SCHED_ULE is much faster than before, but still slower than 6.2-RELEASE.
SCHED_4BSD is still very slow with small HZ.
Thanks,
--
NIIMI Satoshi
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