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SubjectRe: [PATCH] efi: cper: avoid using get_seconds()
On Mon, Jun 18, 2018 at 5:47 PM, Ard Biesheuvel
<ard.biesheuvel@linaro.org> wrote:
> On 18 June 2018 at 16:17, Arnd Bergmann <arnd@arndb.de> wrote:

>> - atomic64_set(&seq, ((u64)get_seconds()) << 32);
>> + if (!atomic64_read(&seq)) {
>> + time64_t time = ktime_get_real_seconds();
>> +
>> + /*
>> + * This code is unlikely to still be needed in year 2106,
>> + * but just in case, let's use a few more bits for timestamps
>> + * after y2038 to be sure they keep increasing monotonically
>> + * for the next few hundred years...
>> + */
>> + if (time < 0x80000000)
>> + atomic64_set(&seq, (ktime_get_real_seconds()) << 32);
>> + else
>> + atomic64_set(&seq, 0x8000000000000000ull |
>> + ktime_get_real_seconds() << 24);
>> + }
>
> Given that these values are never decoded and interpreted as
> timestamps, can't we simply switch to the second flavour immediately?

I considered that, but the downside would be that all future filenames would
come before all past file names. I don't know if the order is important at
all, but the current implementation at least looks like it's intended to keep
all file names strictly sorted across boots.

Arnd

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