Peering into the Linux Kernel with Trace

Peering into the Linux Kernel with trace June 04, 2020 Recently, I was working on a patch for a popular open-source project, and discovered that the test suite was failing intermittently. A closer look revealed that the last access time for some files in the project folder were changing unexpectedly, and this was causing a test to fail. (The failing test was not related to my patch.) Looking at the project code, it seemed impossible for it to be unexpectedly accessing those files during the test in question. Running the test case under strace confirmed that this was not happening. But incontrovertibly, the access times were changing. Could another process on the same machine be reading those files? But why? Could it be a bug in the operating system? Were my tools lying to me? Faced with a puzzle like this, the inclination might be to shrug one’s shoulders and forget about it, perhaps with a dismissive remark about the general brokenness of most software. (I’ve done that many times.) ... Read full article.