Messages in this thread | | | Date | Tue, 29 May 2018 11:54:59 +0300 | From | Leon Romanovsky <> | Subject | Re: [PATCH] IB/mad: Use ID allocator routines to allocate agent number |
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On Tue, May 29, 2018 at 09:38:08AM +0200, Hans Westgaard Ry wrote: > The agent TID is a 64 bit value split in two dwords. The least > significant dword is the TID running counter. The most significant > dword is the agent number. In the CX-3 shared port model, the mlx4 > driver uses the most significant byte of the agent number to store the > slave number, making agent numbers greater and equal to 2^24 (3 bytes) > unusable. The current codebase uses a variable which is incremented > atomically for each new agent number giving too large agent numbers > over time. The IDA set of functions are used instead of the simple > counter approach. This allows re-use of agent numbers. A sysctl > variable is also introduced, to control the max agent number.
Why don't you simply limit this number per-driver? By default, any variable is allowed and mlx4_ib will set something else.
What is the advantage of having sysctl?
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