On Fri, Aug 3, 2012 at 11:56 AM, Pandita, Vikram <vikram.pand...@ti.com> wrote: > On Fri, Aug 3, 2012 at 2:48 AM, Kay Sievers <k...@vrfy.org> wrote: >> On Fri, Aug 3, 2012 at 11:36 AM, Pandita, Vikram <vikram.pand...@ti.com> >> wrote: >>> On Fri, Aug 3, 2012 at 2:32 AM, Venu Byravarasu <vbyravar...@nvidia.com> >>> wrote: >> >>>> As having Macro locally in the file of interest would serve the purpose, >>>> Why to change the printk code? >>> >>> As stated, the logic followed is exactly similar to well proven and >>> approved way to handle printk time stamp: CONFIG_PRINTK_TIME >>> Its an overhead on the system that enables the config option: >>> CONFIG_PRINTK_CPUID >>> Otherwise the system remains as is. >>> >>> To gain insight on SMP system logging behavior, the price to pay is >>> the extra 4 chars per printk line, >>> just like printk-time adds 15 chars to each line. Both options can be >>> disabled as desired. >>> >>> So i am not sure what kind of option you are proposing? >>> Do u imply PRINTK_TIME is not right then? >> >> It's 8 bytes per message for storing the timestamp in the records. >> There is never 15 bytes storage space needed, the prefix is >> constructed on-the-fly only while exporting the data. > > When i was referring to 15 chars, its coming from here: > Its the space reserved in each line of output. Corresponding space for > cpuid is 4 chars: "[x] ":
Just saying, that's just the length of the printed line to the console or syslog, there is no reservation or space used for that internally. >> The CPU-ID would need at least two additional bytes (2^16 CPUS) in >> every record, unless it's a compile-time option. > > are u proposing: > a) to make cpuid a u16? That would be needed, I guess. We easily have server systems with more than 255 CPUs. It will only be a matter of time, that the number of CPUs will increase for everybody, I guess. > b) to put cpuid in struct cont and struct log - under the #ifdef macro? As said, I really can't tell how generally useful it is, and if people think that it should be there unconditionally, should not be there at all, or as a compile time option. Others might have an opinion on that. I personally never missed the CPU-ID in the logs. I personally would find the PID/task ID more interesting, and even that I never really missed. :) Kay -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
