From mboxrd@z Thu Jan 1 00:00:00 1970 From: Edward Shishkin Subject: Re: Reiser4 und LZO compression Date: Thu, 31 Aug 2006 16:00:47 +0400 Message-ID: <44F6CF6F.5010605@namesys.com> References: <20060827003426.GB5204@martell.zuzino.mipt.ru> <44F4914A.1010005@slaphack.com> <44F4979E.9020101@namesys.com> <44F49D7F.3010403@slaphack.com> <0954BE4F-E3A4-4A59-B275-10C1D8DB5101@smartgames.ca> <44F4C2C9.3070101@slaphack.com> <44F5C1D7.5060904@namesys.com> <44F5C313.40905@namesys.com> <194f62550608310232h3425638dx9876abb7f0f88422@mail.gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: list-help: list-unsubscribe: list-post: Errors-To: flx@namesys.com In-Reply-To: <194f62550608310232h3425638dx9876abb7f0f88422@mail.gmail.com> List-Id: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: Clemens Eisserer Cc: reiserfs-list@namesys.com Clemens Eisserer wrote: >> But speaking of single threadedness, more and more desktops are shipping >> with ridiculously more power than people need. Even a gamer really > > Will the LZO compression code in reiser4 be able to use multi-processor > systems? > E.g. if I've a Turion-X2 in my laptop will it use 2 threads for > compression/decompression making cpu throughput much better than > whatthe disk could do? > Compression is going in flush time and there can be more then one flush thread that processes the same transaction atom. Decompression is going in the context of readpage/readpages. So if you mean per file, then yes for compression and no for decompression. Edward. > lg Clemens > > > 2006/8/30, Hans Reiser : > >> Edward Shishkin wrote: >> > >> > (Plain) file is considered as a set of logical clusters (64K by >> > default). Minimal unit occupied in memory by (plain) file is one >> > page. Compressed logical cluster is stored on disk in so-called >> > "disk clusters". Disk cluster is a set of special items (aka "ctails", >> > or "compressed bodies"), so that one block can contain (compressed) >> > data of many files and everything is packed tightly on disk. >> > >> > >> > >> So the compression unit is 64k for purposes of your benchmarks. >> > >