From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gordan Bobic Subject: Re: reiser4 mkfs, cryptcompress, tail packing, etc. Date: Tue, 24 Aug 2010 20:14:10 +0100 Message-ID: <4C741A02.3090004@bobich.net> References: <4C73EDEF.8020701@bobich.net> <4C7405CF.3040609@gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4C7405CF.3040609@gmail.com> Sender: reiserfs-devel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: reiserfs-devel@vger.kernel.org On 08/24/2010 06:47 PM, Edward Shishkin wrote: >> Also, is there a nolog option on reiser4 as there is on reiserfs? > > no sorry, currently reiser4 transaction manager can not be switched off. Is there a way to use an external journal and point it at a different device (e.g. ramdisk/tmpfs), and force fsck on unclean shutdown instead? >> Another question (not sure if it is specifically related to reiser4 or >> generic) is about compressed hard-linked DLLs and mmap. Specifically, >> if a .so is hard-linked in two places, dynamically linking to each >> instance causes both to be mmapped to the same memory since they'll >> have the same inode, and that means the memory is only used once. How >> does this work if the .so is compressed? Does it all still work the >> same, with the decompressed file being in a single mmap for both >> dynamically linked instances? > > Works as usual: when populating address space by readpage(s) data are > read from disk and decompressed. > If page gets dirty, then its data will be compressed in flush time and > written to disk. What about the hard-link issue I mentioned? If two hard-links point to the same inode with a compressed shared library, will it work as expected and only map the file into shared memory once even if both .so files are dyna-linked by different running binaries? Gordan