kernel defconfig, CONFIG_MTD_NAND_VERIFY_WRITE
Patryk.Benderz at esp.pl
Wed Jan 6 16:16:55 CET 2010
Dnia 2010-01-06, śro o godzinie 12:49 +0300, Gennady Kupava pisze:
> hi all,
> I still don't beleive our device should be so slow as it is now. I'll
> try to investigate performance impact of several kernel option. I
> expect, changes will be introduced to defalt config for distributions.
> Here is first one CONFIG_MTD_NAND_VERIFY_WRITE.
> Now it is enabled.
> I build kernel with and without this option, and did read and write
> tests to /dev/mtd6 and /dev/mtdblock6. all tests done with dd
> to/from /dev/zero bs=256k count=200. read is just for check.
> most data in Mb/s.
> mtd6-rd, mtd6-wt, mtdblock6-rd, mtdblock6-wt
> option on 5.2, 4.8, 2.6, 900kb/s
> option off 5.2, 2.4, 2.6, 712kb/s
Well, if this test was repeated several times with similar results, it
might be worth to disable this option IMHO. Only one thing makes me
dither. Will this be safe? I mean, what if there is some software which
takes advantage of this option? Maybe some kind of software which
verifies (using this kernel option) what it writes to device?
Just a thought...
Patryk "LeadMan" Benderz
Linux Registered User #377521
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