Messages in this thread | | | Date | Fri, 01 Nov 2013 21:08:26 +0100 | From | Richard Weinberger <> | Subject | Re: [PATCH] Make efi-pstore return a unique id |
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Am 01.11.2013 20:22, schrieb Seiji Aguchi: >>>> +{ >>>> + char id_str[64]; >>>> + u64 id = 0; >>>> + >>>> + sprintf(id_str, "%lu%u%d", timestamp, part, count); >>>> + if (kstrtoull(id_str, 10, &id)) >>>> + pr_warn("efi-pstore: failed to generate id\n"); >>>> + return id; >>>> +} >>> >>> This is just odd. You make a string from three ints and then a parse >>> it to a int again. >> >> Agreed. I liked your ((timestamp * 100 + part) * 100 + count function much >> more than this. > > I was worried that the part and count could be more than 100. > If it happens, the id may not be unique... > > But, currently, size of nvram storage is limited, so it is a corner case. > I respect your opinion.
What about feeding the bytes of all three integers into a non-cryptographic hash function? Using this way you get a cheap unique id.
Thanks, //richard
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