view Documentation/aoe/todo.txt @ 854:950b9eb27661

usbback: fix urb interval value for interrupt urbs.

Signed-off-by: Noboru Iwamatsu <n_iwamatsu@jp.fujitsu.com>
author Keir Fraser <keir.fraser@citrix.com>
date Mon Apr 06 13:51:20 2009 +0100 (2009-04-06)
parents 831230e53067
line source
1 There is a potential for deadlock when allocating a struct sk_buff for
2 data that needs to be written out to aoe storage. If the data is
3 being written from a dirty page in order to free that page, and if
4 there are no other pages available, then deadlock may occur when a
5 free page is needed for the sk_buff allocation. This situation has
6 not been observed, but it would be nice to eliminate any potential for
7 deadlock under memory pressure.
9 Because ATA over Ethernet is not fragmented by the kernel's IP code,
10 the destructore member of the struct sk_buff is available to the aoe
11 driver. By using a mempool for allocating all but the first few
12 sk_buffs, and by registering a destructor, we should be able to
13 efficiently allocate sk_buffs without introducing any potential for
14 deadlock.