From mboxrd@z Thu Jan 1 00:00:00 1970 From: Edward Shishkin Subject: Re: Reiser4 documentation & specifically current status of repacker, compression, and semantics Date: Thu, 27 Oct 2005 17:48:56 +0400 Message-ID: <4360DAC8.9060507@namesys.com> References: <200510231850.45209.jgilmore@glycou.com> <200510241225.45686.jgilmore@glycou.com> <435D3110.8060204@namesys.com> <200510241345.17620.jgilmore@glycou.com> <435D4DF5.4090602@namesys.com> <435E8237.5050304@namesys.com> <435EADEB.9090402@namesys.com> <435F89E5.4000303@namesys.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: <435F89E5.4000303@namesys.com> List-Id: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: Hans Reiser Cc: John Gilmore , reiserfs-list@namesys.com Edward Shishkin wrote: > Hans Reiser wrote: > >> Particularly, define whether large >> files that cannot be compressed get stored using extents and everything >> else that regular files use. >> >> >> > > Currently files powered by cryptcompress file plugin have its data > stored only in the > items of CTAIL_ID > >> Also, I thought we convert at first flush time, not at every flush >> time. Did you write it to check at every flush? > > > no, just turning off and no anymore check, but it can be easily changed > >> Not entirely sure we >> want to do that for large multimedia files that are compressed by >> hardware, it could add a bunch of CPU, and I would think it would be >> more complex code, because now you have to convert extents, etc. >> > > Yes, such converting seems to be a complicated workaround. We will need > something like "clustered extents" > So having such "cextents" instead of incompressible ctails on leaf level will reduce (/=2 times) memory usage and response to emergency flush (currently there are no any chances for cryptcompress files to be eflushed). Edward.