Messages in this thread | | | Date | Thu, 19 Feb 2009 14:08:20 +0200 | Subject | Disable aggregation of requests to a block device | From | Erez Zilber <> |
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Hi,
I'm running I/O to a block device (which is an iSCSI device, but that shouldn't matter), usually with transfer length = 128kB. From time to time, I see that 2 128kB commands get aggregated to a single 256kB command, which is bad for me because the resources that I allocate are based on 128kB commands. I could limit the command size by setting /sys/block/sdX/queue/max_sectors_kb to 128kB, but sometimes I expect larger commands (e.g. 512kB), and I don't want the block layer to split them into smaller commands.
My question is: can I disable this aggregation? If yes, how? Else, is there another solution?
Thanks, Erez
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