Messages in this thread | | | Date | Wed, 21 Aug 2013 09:34:30 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH] x86, mm: Avoid step_size overflow and add comments |
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* Yinghai Lu <yinghai@kernel.org> wrote:
> Current code
"Current code has two problems:"
> 1. shift step_size directly, and this could have overflow problem > after we shift step_size several times.
The most important piece of information is not explained: under what circumstances can this happen currently, what are the symptoms if this happens, roughly what kind of systems are affected, etc?
I mean the kind of information you'd put into a BIOS errata description or into any software changelog. You wouldn't primarily write about the mechanics of the change, but about the _actual impact_ of the change, to end users, right?
> 2. use MACRO to have shift to set to 5, but there is not > explanation about selection. > > We can fix them with: > 1. Add get_new_step_size(), and check overflow by comparing new_size > with old step_size. > 2. add comment in it about why we are using 5. > > That will make code more readable while not increasing size of > init_mem_mapping().
Well, it gets not just more readable at a small size increase, but also the above unexplained overflow bug will be fixed as well, right?
Thanks,
Ingo
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