My reasoning was around something like:
1) tsc_khz is declared as unsigned int tsc_khz;
2) tsc_khz * 1000 would overflow, if the result is larger, than an
unsigned int could hold;
3) given tsc_khz * 1000 > UINT_MAX is bad, tsc_khz > UINT_MAX / 1000 is bad;
4) if UINT_MAX is 4294967295, than tsc_khz > 4294967.295 is bad, for
example 4294968 would lead to overflow;
5) 4294968 kHz is 4294.968 MHz, which seems realistically high to me.
For me, tsc: Refined TSC clocksource calibration: 3393.624 MHz
(seems like, it is derived from the same value,
pr_info("Refined TSC clocksource calibration: %lu.%03lu MHz\n",
(unsigned long)tsc_khz / 1000,
(unsigned long)tsc_khz % 1000);
)
Not sure about the math above, but it seemed reasonable enough to me to
switch to overflow-resilient arithmetic here.
On 11/21/23 23:14, Rafael J. Wysocki wrote:
On Tue, Nov 21, 2023 at 8:56 PM Rafael J. Wysocki <rafael@xxxxxxxxxx> wrote:
That should be "hundreds of thousands of kHz", so I was mistaken.
But anyway:
Why is it really a concern?
