BufferCache: Find direction of the stream buffer increase.

This commit is contained in:
Fernando Sahmkow 2022-01-31 10:07:01 +01:00
parent 11099dda2e
commit 3b0d233cbd

View file

@ -1464,19 +1464,27 @@ typename BufferCache<P>::OverlapResult BufferCache<P>::ResolveOverlaps(VAddr cpu
overlap_ids.push_back(overlap_id); overlap_ids.push_back(overlap_id);
overlap.Pick(); overlap.Pick();
const VAddr overlap_cpu_addr = overlap.CpuAddr(); 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; 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(); stream_score += overlap.StreamScore();
if (stream_score > STREAM_LEAP_THRESHOLD && !has_stream_leap) { 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 // 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. // as a stream buffer. Increase the size to skip constantly recreating buffers.
has_stream_leap = true; has_stream_leap = true;
begin -= PAGE_SIZE * 256; if (expands_right) {
cpu_addr = begin; begin -= PAGE_SIZE * 256;
end += PAGE_SIZE * 256; cpu_addr = begin;
}
if (expands_left) {
end += PAGE_SIZE * 256;
}
} }
} }
return OverlapResult{ return OverlapResult{