linux-kernel - [patch] [bugfix] loop.c

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Message-ID: <4603DE86.1090009@slax.org>
Date:	Fri, 23 Mar 2007 15:04:54 +0100
From:	Tomas M <tomas@...x.org>
To:	linux-kernel@...r.kernel.org
Subject: [patch] [bugfix] loop.c

I posted this yesterday but it seems people didn't understand the real 
goal of my patch. So I will explain once more again:

This is a bugfix for loop.c block driver, as it currently allocates more 
memory then it needs, without any further use.

If 'max_loop=255' parameter is given, the loop.c driver allocates this 
amount of memory:

   kmalloc(max_loop * sizeof(struct loop_device))

But in this case, (max_loop * sizeof) is greater than 65536, and thus 
kmalloc must allocate the next bigger size (which is 128KB of RAM).

Unfortunately the loop.c driver doesn't allow users to use bigger 
max_loop then 255 (for reasons which are completely obsolete) so the 
rest of memory is *unused*.

This patch doesn't fix unused memory in the case of max_loop=255, but 
rather it allows user to specify bigger max_loop (up to 455 on 386), so 
  the user can fully use all the memory, which would be allocated anyway.

Thank you for your consideration

Tomas M
slax.org

View attachment "loop.c.diff" of type "text/x-patch" (1049 bytes)