From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from a.ns.miles-group.at ([95.130.255.143] helo=radon.swed.at) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Z1tsz-0002iN-NS for linux-mtd@lists.infradead.org; Mon, 08 Jun 2015 10:02:30 +0000 Message-ID: <5575681D.20905@nod.at> Date: Mon, 08 Jun 2015 12:02:05 +0200 From: Richard Weinberger MIME-Version: 1.0 To: Dongsheng Yang , adrian.hunter@intel.com, dedekind1@gmail.com Subject: Re: [PATCH] ubifs: Introduce a mount option of force_atime. References: <1433752038-17276-1-git-send-email-yangds.fnst@cn.fujitsu.com> <557555F6.4030009@nod.at> <55755C48.4080802@cn.fujitsu.com> <5575616C.5090504@nod.at> <55756665.5070805@cn.fujitsu.com> In-Reply-To: <55756665.5070805@cn.fujitsu.com> Content-Type: text/plain; charset=iso-8859-15 Content-Transfer-Encoding: 7bit Cc: linux-mtd@lists.infradead.org List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Am 08.06.2015 um 11:54 schrieb Dongsheng Yang: > On 06/08/2015 05:33 PM, Richard Weinberger wrote: >> Am 08.06.2015 um 11:11 schrieb Dongsheng Yang: >>> On 06/08/2015 04:44 PM, Richard Weinberger wrote: >>>> Am 08.06.2015 um 10:27 schrieb Dongsheng Yang: >>>>> Currently, ubifs does not support access time anyway. I understand >>>>> that there is a overhead to update inode in each access from user. >>>>> >>>>> But for the following two reasons, I think we can make it optional >>>>> to user. >>>>> >>>>> (1). More and more flash storage in server are trying to use ubifs, >>>>> it is not only for a device such as mobile phone any more, we want >>>>> to use it in more and more generic way. Then we need to compete >>>>> with some other main filesystems. From this point, access time is >>>>> necessary to us, at least as a choice to user currently. >>>> >>>> Do you have a reference? I know that modern servers use a lot of SSDs >>>> which use internally NAND (mostly MLC and TLC). >>>> But which systems use RAW NAND where they would care about the atime? >>> >>> Hi Richard, >>> >>> Thanx for your quick response here. >>> >>> http://www.slideshare.net/FujitsuTS/bos-c113a-data-will-change-business-but-will-it-really-change-ict >>> I am not sure is that url available to you. But that's what my team is >>> focus on. It's about a server-using NAND device. >> >> So, you want to use UBI/UBIFS on NAND attached via PCEe? >> Is this SLC NAND? (UBI and UBIFS was designed with SLC in mind). >> MLC and TLC are a major challenge for UBI/UBIFS. > > It's SLC. Where can i get one of those? ;-) Thanks, //richard