Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932340Ab2JJCc5 (ORCPT ); Tue, 9 Oct 2012 22:32:57 -0400 Received: from mailout4.samsung.com ([203.254.224.34]:57813 "EHLO mailout4.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932318Ab2JJCcv convert rfc822-to-8bit (ORCPT ); Tue, 9 Oct 2012 22:32:51 -0400 X-AuditID: cbfee61b-b7f2b6d000000f14-41-5074de500f0a From: Jaegeuk Kim To: "'Dave Chinner'" Cc: "=?utf-8?Q?'Luk=C3=A1=C5=A1_Czerner'?=" , "'Namjae Jeon'" , "'Vyacheslav Dubeyko'" , "'Marco Stornelli'" , "'Jaegeuk Kim'" , "'Al Viro'" , tytso@mit.edu, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, chur.lee@samsung.com, cm224.lee@samsung.com, jooyoung.hwang@samsung.com, linux-fsdevel@vger.kernel.org References: <50712AAA.5030807@gmail.com> <002201cda46e$88b84d30$9a28e790$%kim@samsung.com> <004101cda52e$72210e20$56632a60$%kim@samsung.com> <004a01cda542$f398e2c0$dacaa840$%kim@samsung.com> <007c01cda60b$43e7fae0$cbb7f0a0$%kim@samsung.com> <008301cda615$ca3b9980$5eb2cc80$%kim@samsung.com> <20121009212012.GO23644@dastard> In-reply-to: <20121009212012.GO23644@dastard> Subject: RE: [PATCH 00/16] f2fs: introduce flash-friendly file system Date: Wed, 10 Oct 2012 11:32:48 +0900 Message-id: <008c01cda68f$8990e140$9cb2a3c0$%kim@samsung.com> MIME-version: 1.0 Content-type: text/plain; charset=utf-8 Content-transfer-encoding: 8BIT X-Mailer: Microsoft Office Outlook 12.0 Thread-index: Ac2mY+PzfwcmQgZvSbKuF0fQEbu0AAAKEmTA Content-language: ko X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrPLMWRmVeSWpSXmKPExsVy+t9jAd2AeyUBBq9mK1js2XuSxeLyrjls DkwenzfJBTBGcdmkpOZklqUW6dslcGVM/n6fueCiSsXxiTtYGxgnynYxcnBICJhIrJzv3sXI CWSKSVy4t56ti5GLQ0hgEaPEhJ8noJx/jBJH57WzgjSwCWhLbN5vANIgIqAhMW3vEWaQGmaB k8wSPdvmM0I0nGeRmLL0KRNIA6eArsTBBREgDcICrhLtf9oZQWwWAVWJ6UcOsIPYvAK2ElN/ PWWEsAUlfky+xwLSyiygLjFlSi5ImBlo7ZN3F1ghblaXePRXF+IEI4mmly9ZIUpEJPa9eMc4 gVFoFpJBsxAGzUIyaBaSjgWMLKsYRVMLkguKk9JzjfSKE3OLS/PS9ZLzczcxgoP5mfQOxlUN FocYBTgYlXh4KzJKAoRYE8uKK3MPMUpwMCuJ8MqsBArxpiRWVqUW5ccXleakFh9ilOZgURLn bfZICRASSE8sSc1OTS1ILYLJMnFwSjUw2ukvlHmt//po3YX7WuEnFusdaD/8w8yOi729V+qk d63hxDSf/Rfj9+V78X3/JLcx+OW5axuyfNx5mXb+X3kurHHjhbnyk7jPCE/XzpPN8G+fyuwU 53X9VvYTtR8l/xbHH97VZ3ws6unXU1JmSsoNaqURUfL8ftsSfbozYlI1XN3XTNj248tMJZbi jERDLeai4kQAsCjFEmICAAA= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4711 Lines: 102 > -----Original Message----- > From: linux-fsdevel-owner@vger.kernel.org [mailto:linux-fsdevel-owner@vger.kernel.org] On Behalf Of > Dave Chinner > Sent: Wednesday, October 10, 2012 6:20 AM > To: Jaegeuk Kim > Cc: 'Lukáš Czerner'; 'Namjae Jeon'; 'Vyacheslav Dubeyko'; 'Marco Stornelli'; 'Jaegeuk Kim'; 'Al Viro'; > tytso@mit.edu; gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org; chur.lee@samsung.com; > cm224.lee@samsung.com; jooyoung.hwang@samsung.com; linux-fsdevel@vger.kernel.org > Subject: Re: [PATCH 00/16] f2fs: introduce flash-friendly file system > > [ Folks, can you trim your responses down to just quote the part you > are responding to? Having to repeatedly scroll through 500 lines of > irrelevant text just to find the 5 lines that is being commented on > is exceedingly painful. ] Ok, I'll keep in mind. Thanks. > > On Tue, Oct 09, 2012 at 09:01:18PM +0900, Jaegeuk Kim wrote: > > > From: Lukáš Czerner [mailto:lczerner@redhat.com] > > > > > I am sorry but this reply makes me smile. How can you design a fs > > > > > relying on time attack heuristics to figure out what the proper > > > > > layout should be ? Or even endorse such heuristics to be used in > > > > > mkfs ? What we should be focusing on is to push vendors to actually > > > > > give us such information so we can properly propagate that > > > > > throughout the kernel - that's something everyone will benefit from. > > > > > After that the optimization can be done in every file system. > > > > > > > > > > > > > Frankly speaking, I agree that it would be the right direction eventually. > > > > But, as you know, it's very difficult for all flash vendors to promote and standardize that. > > > > Because each vendors have different strategies to open their internal information and also try > > > > to protect their secrets whatever they are. > > > > > > > > IMO, we don't need to wait them now. > > > > Instead, from the start, I suggest f2fs that uses those information to the file system design. > > > > In addition, I suggest using heuristics right now as best efforts. > > And in response, other people are "suggesting" that this is the > wrong approach. Ok, it makes sense. I agree that the Linaro survey has been well proceeded, and no more heuristic is needed. > > > > > Maybe in future, if vendors give something, f2fs would be more feasible. > > > > In the mean time, I strongly hope to validate and stabilize f2fs with community. > > > > > > Do not get me wrong, I do not think it is worth to wait for vendors > > > to come to their senses, but it is worth constantly reminding that > > > we *need* this kind of information and those heuristics are not > > > feasible in the long run anyway. > > > > > > I believe that this conversation happened several times already, but > > > what about having independent public database of all the internal > > > information about hw from different vendors where users can add > > > information gathered by the time attack heuristic so other does not > > > have to run this again and again. I am not sure if Linaro or someone > > > else have something like that, someone can maybe post a link to that. > > Linaro already have one, which is another reason why using > heuristics is the wrong approach: > > https://wiki.linaro.org/WorkingGroups/Kernel/Projects/FlashCardSurvey?action=show&redirect=WorkingGrou > ps%2FKernelConsolidation%2FProjects%2FFlashCardSurvey > > > As I mentioned, I agree to push vendors to open those information all the time. > > And, I absolutely didn't mean that it is worth to wait vendors. > > I meant, until opening those information by vendors, something like > > proposing f2fs or gathering heuristics are also needed simultaneously. > > > > Anyway, it's very interesting to build a database gathering products' information. > > May I access the database? > > It's public information. > > If you want to support different types of flash, then either add > your timing attack derived information on specific hardware to the > above table, or force vendors to update it themselves if they want > their flash memory supported by this filesystem. Sound good. If I also get something, I'll try. Thank you. > > Cheers, > > Dave. > -- > Dave Chinner > david@fromorbit.com > -- > To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/