diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2020-06-11 15:17:57 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-06-11 15:17:57 +0200 |
| commit | f77d26a9fc525286bcef3d4f98b52e17482cf49c (patch) | |
| tree | 6b179c9aa84787773cb601a14a64255e2912154b /include/linux/cache.h | |
| parent | b6bea24d41519e8c31e4798f1c1a3f67e540c5d0 (diff) | |
| parent | f0178fc01fe46bab6a95415f5647d1a74efcad1b (diff) | |
Merge branch 'x86/entry' into ras/core
to fixup conflicts in arch/x86/kernel/cpu/mce/core.c so MCE specific follow
up patches can be applied without creating a horrible merge conflict
afterwards.
Diffstat (limited to 'include/linux/cache.h')
| -rw-r--r-- | include/linux/cache.h | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/include/linux/cache.h b/include/linux/cache.h index 750621e41d1c..1aa8009f6d06 100644 --- a/include/linux/cache.h +++ b/include/linux/cache.h @@ -15,8 +15,14 @@ /* * __read_mostly is used to keep rarely changing variables out of frequently - * updated cachelines. If an architecture doesn't support it, ignore the - * hint. + * updated cachelines. Its use should be reserved for data that is used + * frequently in hot paths. Performance traces can help decide when to use + * this. You want __read_mostly data to be tightly packed, so that in the + * best case multiple frequently read variables for a hot path will be next + * to each other in order to reduce the number of cachelines needed to + * execute a critical path. We should be mindful and selective of its use. + * ie: if you're going to use it please supply a *good* justification in your + * commit log */ #ifndef __read_mostly #define __read_mostly |