Date: Thu, 08 Mar 2018 11:42:36 +0100 From: "Ronald Klop" <ronald-lists@klop.ws> To: "Bernd Walter" <ticso@cicely7.cicely.de>, ticso@cicely.de Cc: freebsd-fs@freebsd.org, "freebsd-arm@freebsd.org" <freebsd-arm@freebsd.org> Subject: Re: gstat more writes per seconds than there are seconds per write Message-ID: <op.zfjz1auwkndu52@klop.ws> In-Reply-To: <20180308102010.GB80981@cicely7.cicely.de> References: <op.zfjycxctkndu52@klop.ws> <20180308102010.GB80981@cicely7.cicely.de>
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On Thu, 08 Mar 2018 11:20:10 +0100, Bernd Walter <ticso@cicely7.cicely.de> wrote: > On Thu, Mar 08, 2018 at 11:06:23AM +0100, Ronald Klop wrote: >> Hello, >> >> I'm confused by this output. >> w/s = 5, but ms/w is 1108; how can I put 5 writes in a second if the >> average write takes more than a second? > > It is the time a request has to wait until it is done. > But your L(q) says that 17 are queued. Thanks, that makes sense. Any ideas how to retrieve the ms/w without the time-in-queue included? Regards, Ronald. > >> Is my SD card super parallel? :-) > > Maybe, maybe not, flash device vendors don't tell how they work > internally, which is a shame, but you can only request a single > transaction with an SD card. > On USB sticks you might be able to do tagged command queuing, > not that many support that... > Nevertheless you can always queue more than one request at the OS layer. > >> Sometimes the numbers are even higher. >> >> dT: 1.010s w: 1.000s >> L(q) ops/s r/s kBps ms/r w/s kBps ms/w %busy Name >> 17 5 0 0 0.0 5 420 1108 81.7 mmcsd0 >> 0 0 0 0 0.0 0 0 0.0 0.0 da0 >> 0 0 0 0 0.0 0 0 0.0 0.0 mmcsd0s1 >> 17 5 0 0 0.0 5 420 1108 81.7 mmcsd0s2 >> 0 0 0 0 0.0 0 0 0.0 0.0 >> msdosfs/MSDOSBOOT >> 17 5 0 0 0.0 5 420 1108 81.7 mmcsd0s2a >> 17 5 0 0 0.0 5 420 1108 81.7 ufs/rootfs >> >> [root@rpi2 ~]# uname -a >> dmesg | grep mmc >> FreeBSD rpi2 11.1-RELEASE-p6 FreeBSD 11.1-RELEASE-p6 #0 r328567: Tue Jan >> 30 20:10:37 CET 2018 >> root@rpi2:/mnt/usbdisk/usr/obj/mnt/usbdisk/usr/src/sys/RPI2 arm >> >> [root@rpi2 ~]# dmesg | grep mmc >> mmc0: <MMC/SD bus> on sdhci_bcm0 >> mmc0: CMD8 failed, RESULT: 1 >> mmcsd0: 2GB <SD SMI 1.0 SN 1736A86C MFG 05/2007 by 27 SM> at mmc0 >> 41.6MHz/4bit/65535-block >> >> Regards, >> Ronald. >> _______________________________________________ >> freebsd-arm@freebsd.org mailing list >> https://lists.freebsd.org/mailman/listinfo/freebsd-arm >> To unsubscribe, send any mail to "freebsd-arm-unsubscribe@freebsd.org"
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