Re: [PATCH V7 1/4] perf/core: Add PERF_SAMPLE_DATA_PAGE_SIZE

From: Liang, Kan
Date: Thu Sep 17 2020 - 18:16:25 EST




On 9/17/2020 6:02 PM, Dave Hansen wrote:
The problem is that the warning from the perf tool usually includes some
hints regarding the cause of the warning or possible solution to
workaround/fix the warning. What message should we deliver to the users?
"Warning: Too many error page size. Address space isolation feature may
be enabled, please check"?
That's not particularly actionable for an end user. Do any of the perf
errors just tell them to submit a bug report? "Excessive number of page
size lookup errors, please report to..."

Yes, found some perf tool warnings end with "Consider reporting to linux-kernel@xxxxxxxxxxxxxxx."

I will add a warning "Excessive number of page size lookup errors, please report to linux-kernel@xxxxxxxxxxxxxxx.", if 90% of the samples have the page size 0.

Thanks,
Kan