jarin added a comment. Looking at the code for flushing L1 cache <https://github.com/llvm/llvm-project/blob/e609fe68b2c59b145c0a5c66bedbee2bff545200/lldb/source/Target/Memory.cpp#L59-L71>, it appears broken. I am guessing that is the reason for the failure of my patch on the bots.
Here is the L1 <https://reviews.llvm.org/L1> flushing code (after checking L1 <https://reviews.llvm.org/L1> is not empty). AddrRange flush_range(addr, size); BlockMap::iterator pos = m_L1_cache.upper_bound(addr); if (pos != m_L1_cache.begin()) { --pos; } while (pos != m_L1_cache.end()) { AddrRange chunk_range(pos->first, pos->second->GetByteSize()); if (!chunk_range.DoesIntersect(flush_range)) break; pos = m_L1_cache.erase(pos); } For instance, let the cache contains two chunks (10, 10) and (30, 10). Let us flush (25, 10). Then the while loop chunk_range will be (10, 10), which is not intersecting with (25, 10), so we do not flush anything. This is clearly wrong because (30, 10) should be flushed. I am wondering whether something like this would be correct (I am still a bit worried about the case of overlapping things in L1 <https://reviews.llvm.org/L1>). AddrRange flush_range(addr, size); BlockMap::iterator pos = m_L1_cache.upper_bound(addr); if (pos != m_L1_cache.begin()) { // If we are not in the beginning, the previous range might be also intersecting. BlockMap::iterator previous = pos; previous--; AddrRange previous_range(previous->first, previous->second->GetByteSize()) if (!previous_range.DoesIntersect(flush_range)) pos = m_L1_cache.erase(previous); } while (pos != m_L1_cache.end()) { AddrRange chunk_range(pos->first, pos->second->GetByteSize()); if (!chunk_range.DoesIntersect(flush_range)) break; pos = m_L1_cache.erase(pos); } Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D74398/new/ https://reviews.llvm.org/D74398 _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
