Re: [PATCH v3 13/35] lib: add allocation tagging support for memory allocation profiling

On Fri, Feb 16, 2024 at 06:26:06PM -0500, Kent Overstreet wrote:

On Mon, Feb 12, 2024 at 02:40:12PM -0800, Kees Cook wrote:

quoted

On Mon, Feb 12, 2024 at 01:38:59PM -0800, Suren Baghdasaryan wrote:

quoted

diff --git a/include/linux/sched.h b/include/linux/sched.h
index ffe8f618ab86..da68a10517c8 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h

@@ -770,6 +770,10 @@ struct task_struct {
 	unsigned int			flags;
 	unsigned int			ptrace;
 
+#ifdef CONFIG_MEM_ALLOC_PROFILING
+	struct alloc_tag		*alloc_tag;
+#endif

Normally scheduling is very sensitive to having anything early in
task_struct. I would suggest moving this the CONFIG_SCHED_CORE ifdef
area.

This is even hotter than the scheduler members; we actually do want it
up front.

It is? I would imagine the scheduler would touch stuff more than the
allocator, but whatever works. :)

-- 
Kees Cook