On Wed, Jan 03, 2018 at 01:24:59PM +0200, Tariq Toukan wrote: > > > On 03/01/2018 10:06 AM, Julia Lawall wrote: > > > > > > On Wed, 3 Jan 2018, Tariq Toukan wrote: > > > > > > > > > > > On 01/01/2018 10:46 PM, SF Markus Elfring wrote: > > > > From: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx> > > > > Date: Mon, 1 Jan 2018 21:42:27 +0100 > > > > > > > > Omit an extra message for a memory allocation failure in these functions. > > > > > > > > This issue was detected by using the Coccinelle software. > > > > > > > > Signed-off-by: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx> > > > > --- > > > > > > Is this an issue? Why? What is your motivation? > > > These are error messages, very informative, appear only upon errors, and in > > > control flow. > > > > Strings take up space. Since there is a backtrace on an out of memory > > problem, if the string does not provide any more information than the > > position of the call, then there is not much added value. I don't know > > what was the string in this case. If it provides some additional > > information, then it would be reasonable to keep it. > > I don't really accept this claim... > > Short informative strings worth the tiny space they consume. It helps the > users of our driver understand what went wrong in simple words, without the > need to understand the role of the functions/callstack or being familiar > with different parts of the driver code. > > In addition, some out-of-memory errors are recoverable, even though their > backtrace is also printed. For example, in function mlx4_en_create_cq > (appears in patch) we have a first allocation attempt (kzalloc_node) and a > fallback (kzalloc). I'd prefer to state a clear error message only when both > have failed, because otherwise the user might be confused whether the > backtrace should indicate a malfunctioning interface, or not. Tariq, There is standard way to handle fallback in allocation and it is to use __GFP_NOWARN flag in first allocation. So actually you pointed to the "better-to-be-improved" function call. Thanks > > Tariq > > > > > julia > > > > > -- > > > To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in > > > the body of a message to majordomo@xxxxxxxxxxxxxxx > > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-rdma" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html
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