[stgt] [PATCH 1/1] null backing store

[FUJITA Tomonori]

On Wed, 27 Aug 2008 19:39:05 +0300
Alexander Nezhinsky <nezhinsky at gmail.com> wrote:

> 
> From 75c9a58fd094360c59b1bcd3e05a429dd8f68f4d Mon Sep 17 00:00:00 2001
> From: Alexander Nezhinsky <nezhinsky at gmail.com>
> Date: Tue, 26 Aug 2008 17:23:37 +0300
> Subject: [PATCH 1/1] null backing store
> 
> Implements a NULL I/O backing store, which shortcuts all scsi commands
> and returns a success status without actually performing them. 
> Useful for performance measurements, by eliminating or significantly 
> reducing I/O side bottleneck.
> 
> Signed-off-by: Alexander Nezhinsky <nezhinsky at gmail.com>
> ---
>  usr/Makefile  |    2 +-
>  usr/bs_null.c |  103 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Thanks. But you can do faster. This patch incurs the thread and pipe
notification overheads. You don't need bs_thread stuff. See bs_aio.c

After that, you can do more faster. You can use sendfile (send data
without memory copy) though you need some changes to the core code.
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