Merge pull request #7812 from FernandoS27/made-straight-from-the-nut

BufferCache: Find direction of the stream buffer increase.
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bunnei 2022-03-20 15:23:53 -07:00 committed by GitHub
commit ff2e891022
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@ -1469,21 +1469,29 @@ typename BufferCache<P>::OverlapResult BufferCache<P>::ResolveOverlaps(VAddr cpu
overlap_ids.push_back(overlap_id);
overlap.Pick();
const VAddr overlap_cpu_addr = overlap.CpuAddr();
if (overlap_cpu_addr < begin) {
const bool expands_left = overlap_cpu_addr < begin;
if (expands_left) {
cpu_addr = begin = overlap_cpu_addr;
}
end = std::max(end, overlap_cpu_addr + overlap.SizeBytes());
const VAddr overlap_end = overlap_cpu_addr + overlap.SizeBytes();
const bool expands_right = overlap_end > end;
if (overlap_end > end) {
end = overlap_end;
}
stream_score += overlap.StreamScore();
if (stream_score > STREAM_LEAP_THRESHOLD && !has_stream_leap) {
// When this memory region has been joined a bunch of times, we assume it's being used
// as a stream buffer. Increase the size to skip constantly recreating buffers.
has_stream_leap = true;
if (expands_right) {
begin -= PAGE_SIZE * 256;
cpu_addr = begin;
}
if (expands_left) {
end += PAGE_SIZE * 256;
}
}
}
return OverlapResult{
.ids = std::move(overlap_ids),
.begin = begin,