diff mbox series

[v7,net-next,2/5] cache: enforce cache groups

Message ID 20231113233301.1020992-3-lixiaoyan@google.com (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series Analyze and Reorganize core Networking Structs to optimize cacheline consumption | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 16089 this patch: 16089
netdev/cc_maintainers warning 2 maintainers not CCed: catalin.marinas@arm.com akpm@linux-foundation.org
netdev/build_clang success Errors and warnings before: 3607 this patch: 3607
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 17288 this patch: 17288
netdev/checkpatch warning CHECK: Macro argument 'SIZE' may be better as '(SIZE)' to avoid precedence issues
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Coco Li Nov. 13, 2023, 11:32 p.m. UTC 
Set up build time warnings to safeguard against future header changes of
organized structs.

Warning includes:

1) whether all variables are still in the same cache group
2) whether all the cache groups have the sum of the members size (in the
   maximum condition, including all members defined in configs)

Signed-off-by: Coco Li <lixiaoyan@google.com>
Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
---
 include/linux/cache.h | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

Comments

Jakub Kicinski Nov. 15, 2023, 4:32 a.m. UTC | #1 
On Mon, 13 Nov 2023 23:32:58 +0000 Coco Li wrote:
> Set up build time warnings to safeguard against future header changes of
> organized structs.
> 
> Warning includes:
> 
> 1) whether all variables are still in the same cache group
> 2) whether all the cache groups have the sum of the members size (in the
>    maximum condition, including all members defined in configs)

Could you extend scripts/kernel-doc to ignore the new macros?
It's fairly simple script, should hopefully be very easy.
Otherwise using the macros will cause warning spew with W=1.
diff mbox series

Patch

diff --git a/include/linux/cache.h b/include/linux/cache.h
index 9900d20b76c28..0ecb17bb68837 100644
--- a/include/linux/cache.h
+++ b/include/linux/cache.h
@@ -85,6 +85,31 @@ 
 #define cache_line_size()	L1_CACHE_BYTES
 #endif
 
+#ifndef __cacheline_group_begin
+#define __cacheline_group_begin(GROUP) \
+	__u8 __cacheline_group_begin__##GROUP[0]
+#endif
+
+#ifndef __cacheline_group_end
+#define __cacheline_group_end(GROUP) \
+	__u8 __cacheline_group_end__##GROUP[0]
+#endif
+
+#ifndef CACHELINE_ASSERT_GROUP_MEMBER
+#define CACHELINE_ASSERT_GROUP_MEMBER(TYPE, GROUP, MEMBER) \
+	BUILD_BUG_ON(!(offsetof(TYPE, MEMBER) >= \
+		       offsetofend(TYPE, __cacheline_group_begin__##GROUP) && \
+		       offsetofend(TYPE, MEMBER) <= \
+		       offsetof(TYPE, __cacheline_group_end__##GROUP)))
+#endif
+
+#ifndef CACHELINE_ASSERT_GROUP_SIZE
+#define CACHELINE_ASSERT_GROUP_SIZE(TYPE, GROUP, SIZE) \
+	BUILD_BUG_ON(offsetof(TYPE, __cacheline_group_end__##GROUP) - \
+		     offsetofend(TYPE, __cacheline_group_begin__##GROUP) > \
+		     SIZE)
+#endif
+
 /*
  * Helper to add padding within a struct to ensure data fall into separate
  * cachelines.