linux-ext4 - Barriers per second while doing Odirect Random Writes

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 for Android: free password hash cracker in your pocket

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

Date:	Mon, 26 Apr 2010 00:06:17 -0700
From:	Keith Mannthey <kmannth@...ibm.com>
To:	"linux-ext4@...r.kernel.org" <linux-ext4@...r.kernel.org>
Subject: Barriers per second while doing Odirect Random Writes

Ted and all, 
  While using this FFSB test profile:
http://btrfs.boxacle.net/repository/raid/2010-04-14_2004//ext4-2.6.34-rc3-nobarrier//btrfs1.ffsb.random_writes_odirect__threads_0128.10-04-21_17.38.39/benchmark/profile
(The profile is 128 threads of all odirect random writes. )
on my raid box I am seeing (via Darricks block_barrier tracepoint) right
about 32 barriers per second.

Initial analysis using perf shows kdmflush as the cause. I will continue
to look into this.  

Thanks,
  Keith Mannthey
  LTC FS-Dev 

--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html