On Tue, Nov 17, 2015 at 12:52:47AM +0100, Marc Lehmann wrote: > On Mon, Nov 16, 2015 at 12:31:06PM +0800, Chao Yu <[email protected]> > wrote: > > I think you could get the change information in below link: > > > > http://sourceforge.net/p/linux-f2fs/mailman/message/34427519/ > > Right, I saw the merge requests, but I don't know if these have been accepted > for 4.3. I assume they are, thanks for finding them again for me.
Of course, those were merged. > > > > While there are stretches at >>100MB/s, most of the time, this is at less, > > > and often for long stretches at ~10MB/s, which is the reason the end > > > result is (relatively) bad. > > > > Could you please share us IO trace log? > > I am already working on it, I just didn't expect it to be a problem. Also, > I did it without your patch. > > > > And lastly, is there a document describing the implementation of > > > encryption in the fs, and the goals (privacy? integrity? both?) > > > > The feature was ported from ext4, please refer following article: > > > > https://lwn.net/Articles/639427/ > > I see, so it inherits all the security issues of that design. > > > Actually, as I test in flash device, it does help to improve performance in > > workload of creating nodes aggressively, this is because we add asynchronous > > readahead to mitigate small synchronous random read which may block all APPs > > sometime. Considering rotational device has worse random synchronous read > > performance, I expect better result in SMR. > > Ok, that could help, as even a relatively small number of random reads could > cause performance regressions (did the original 3.18 code not yet do this?) > > I was a bit confused by the use of SMR, as SMRs don't suffer more from > random reads as othere rotational devices (in fact, they can suffer less, > if the data is still in the journal). The important point here is that such the read operations to build free nids hurts the concurrency of filesystem operations. > > > > Sure, will be happy to do that, what should I tune how? And thanks for > > > working on this! > > > > IMO, one way is to do the test with default value and then do geometrically > > increasing with the value to see how it affects the IO. > > I am not sure I can make a large number of tests, I will try to do smaller > tests and see if I can make more of them and see a difference. Thanks, > > Thanks again! > > -- > The choice of a Deliantra, the free code+content MORPG > -----==- _GNU_ http://www.deliantra.net > ----==-- _ generation > ---==---(_)__ __ ____ __ Marc Lehmann > --==---/ / _ \/ // /\ \/ / [email protected] > -=====/_/_//_/\_,_/ /_/\_\ > > ------------------------------------------------------------------------------ > Presto, an open source distributed SQL query engine for big data, initially > developed by Facebook, enables you to easily query your data on Hadoop in a > more interactive manner. Teradata is also now providing full enterprise > support for Presto. Download a free open source copy now. > http://pubads.g.doubleclick.net/gampad/clk?id=250295911&iu=/4140 > _______________________________________________ > Linux-f2fs-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel ------------------------------------------------------------------------------ _______________________________________________ Linux-f2fs-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
