Date: Tue, 18 Dec 2007 00:16:37 +0000 From: "Poul-Henning Kamp" <phk@phk.freebsd.dk> To: Bruce M Simpson <bms@incunabulum.net> Cc: cvs-src@FreeBSD.org, src-committers@FreeBSD.org, "Bruce M. Simpson" <bms@FreeBSD.org>, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sbin/atacontrol atacontrol.c Message-ID: <13252.1197936997@critter.freebsd.dk> In-Reply-To: Your message of "Mon, 17 Dec 2007 15:26:19 GMT." <4766951B.8090504@incunabulum.net>
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In message <4766951B.8090504@incunabulum.net>, Bruce M Simpson writes: >Ah, let me rephrase, I meant: > >* NAND Flash embedded ATA controllers should not erase sectors >containing data unless absolutely necessary, to implement wear levelling. That's part of the job description, but it is more complex than that. > * BIO_DELETE provides the necessary hint from the OS, by way of the ATA >CFA ERASE command, to tell the flash controller that the upper layer >consumer of the blocks has marked the data as being erased. Yes. > * The NAND flash ATA controller is *then* in a position to know how >best to implement that wear levelling as the OS has told it "I'm not >using these sectors any more". Possibly. For "best" substitute "better" and I might agree. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence.
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