Date: Tue, 8 Mar 2016 10:34:23 -0800 From: Scott Long <scottl@samsco.org> To: Slawa Olhovchenkov <slw@zxy.spb.ru> Cc: freebsd-stable@freebsd.org Subject: Re: kernel: mps0: Out of chain frames, consider increasing hw.mps.max_chains. Message-ID: <6189E959-3489-438E-8D91-9E5E46E2D482@samsco.org> In-Reply-To: <20160308180746.GE70809@zxy.spb.ru> References: <20160306194555.GC94639@zxy.spb.ru> <0F0C78F4-6FE2-43BA-B503-AA04A79F2E70@samsco.org> <20160306212733.GJ11654@zxy.spb.ru> <DFC3C4CF-89D4-417C-AEBA-67F49F3EA1DE@samsco.org> <20160307060407.GK11654@zxy.spb.ru> <5B8DD95A-9FA0-4E16-85A1-87B54035B3F7@samsco.org> <20160307111012.GL11654@zxy.spb.ru> <20160308180746.GE70809@zxy.spb.ru>
next in thread | previous in thread | raw e-mail | index | archive | help
> On Mar 8, 2016, at 10:07 AM, Slawa Olhovchenkov <slw@zxy.spb.ru> = wrote: >=20 > On Mon, Mar 07, 2016 at 02:10:12PM +0300, Slawa Olhovchenkov wrote: >=20 >>>>>> This allocated one for all controllers, or allocated for every = controller? >>>>>=20 >>>>> It=E2=80=99s per-controller. >>>>>=20 >>>>> I=E2=80=99ve thought about making the tuning be dynamic at = runtime. I >>>>> implemented similar dynamic tuning for other drivers, but it = seemed >>>>> overly complex for low benefit. Implementing it for this driver >>>>> would be possible but require some significant code changes. >>>>=20 >>>> What cause of chain_free+io_cmds_active << max_chains? >>>> One cmd can use many chains? >>>=20 >>> Yes. A request uses and active command, and depending on the size = of the I/O, >>> it might use several chain frames. >=20 > I am play with max_chains and like significant cost of handling > max_chains: with 8192 system resonded badly vs 2048. Now try 3192, > response like with 2048. Hi, I=E2=80=99m not sure I understand what you=E2=80=99re saying. You = said that you tried 8192, but the system still complained of being out = of chain frames? Now you are trying fewer, only 3192? Thanks, Scott
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?6189E959-3489-438E-8D91-9E5E46E2D482>