From: Michael S. Tsirkin Date: Mon, 21 May 2007 16:06:54 +0000 (+0300) Subject: IB/cm: Improve local id allocation X-Git-Tag: v2.6.22-rc3~108^2 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9f81036c54ed1f860d2807c5a6aa4f2b30c21204;p=pandora-kernel.git IB/cm: Improve local id allocation The IB CM uses an idr for local id allocations, with a running counter as start_id. This fails to generate distinct ids if 1. An id is constantly created and destroyed 2. A chunk of ids just beyond the current next_id value is occupied This in turn leads to an increased chance of connection request being mis-detected as a duplicate, sometimes for several retries, until next_id gets past the block of allocated ids. This has been observed in practice. As a fix, remember the last id allocated and start immediately above it. This also fixes a problem with the old code, where next_id might overflow and become negative. Signed-off-by: Michael S. Tsirkin Acked-by: Sean Hefty Signed-off-by: Roland Dreier --- Reading git-diff-tree failed