linux-kernel - Re: Question about Reiser4

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <462D46DF.4090802@zytor.com>
Date:	Mon, 23 Apr 2007 16:53:03 -0700
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Theodore Tso <tytso@....edu>, Eric Hopper <hopper@...ifarious.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	linux-kernel@...r.kernel.org
Subject: Re: Question about Reiser4

Theodore Tso wrote:
> 
> One of the big problems of using a filesystem as a DB is the system
> call overheads.  If you use huge numbers of tiny files, then each
> attempt read an atom of information from the DB takes three system
> calls --- an open(), read(), and close(), with all of the overheads in
> terms of dentry and inode cache.
> 

Now, to be fair, there are probably a number of cases where 
open/lseek/readv/close and open/lseek/writev/close would be worth doing 
as a single system call.  The big problem as far as I can see involves 
EINTR handling; such a system call has serious restartability implications.

Of course, there are Ingo's syslets...

	-hpa
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/