From d075a78a5ab19389d5600923d6ad5391d7cd1be8 Mon Sep 17 00:00:00 2001 From: Akira Yokosawa Date: Sun, 31 May 2020 20:04:32 +0900 Subject: [PATCH] tools/memory-model/README: Expand dependency of klitmus7 klitmus7 is independent of the memory model but depends on the build-target kernel release. It occasionally lost compatibility due to kernel API changes [1, 2, 3]. It was remedied in a backwards-compatible manner respectively [4, 5, 6]. Reflect this fact in README. [1]: b899a850431e ("compiler.h: Remove ACCESS_ONCE()") [2]: 0bb95f80a38f ("Makefile: Globally enable VLA warning") [3]: d56c0d45f0e2 ("proc: decouple proc from VFS with "struct proc_ops"") [4]: https://github.com/herd/herdtools7/commit/e87d7f9287d1 ("klitmus: Use WRITE_ONCE and READ_ONCE in place of deprecated ACCESS_ONCE") [5]: https://github.com/herd/herdtools7/commit/a0cbb10d02be ("klitmus: Avoid variable length array") [6]: https://github.com/herd/herdtools7/commit/46b9412d3a58 ("klitmus: Linux kernel v5.6.x compat") NOTE: [5] was ahead of herdtools7 7.53, which did not make an official release. Code generated by klitmus7 without [5] can still be built targeting Linux 4.20--5.5 if you don't care VLA warnings. Acked-by: Andrea Parri Signed-off-by: Akira Yokosawa Signed-off-by: Paul E. McKenney --- tools/memory-model/README | 30 ++++++++++++++++++++++++++++-- 1 file changed, 28 insertions(+), 2 deletions(-) diff --git a/tools/memory-model/README b/tools/memory-model/README index b9c562e92981..90af203c3cf1 100644 --- a/tools/memory-model/README +++ b/tools/memory-model/README @@ -28,8 +28,34 @@ downloaded separately: See "herdtools7/INSTALL.md" for installation instructions. Note that although these tools usually provide backwards compatibility, -this is not absolutely guaranteed. Therefore, if a later version does -not work, please try using the exact version called out above. +this is not absolutely guaranteed. + +For example, a future version of herd7 might not work with the model +in this release. A compatible model will likely be made available in +a later release of Linux kernel. + +If you absolutely need to run the model in this particular release, +please try using the exact version called out above. + +klitmus7 is independent of the model provided here. It has its own +dependency on a target kernel release where converted code is built +and executed. Any change in kernel APIs essential to klitmus7 will +necessitate an upgrade of klitmus7. + +If you find any compatibility issues in klitmus7, please inform the +memory model maintainers. + +klitmus7 Compatibility Table +---------------------------- + + ============ ========== + target Linux herdtools7 + ------------ ---------- + -- 4.18 7.48 -- + 4.15 -- 4.19 7.49 -- + 4.20 -- 5.5 7.54 -- + 5.6 -- HEAD + ============ ========== ==================