tools/perf/check-header_ignore_hunks/lib/list_sort.c

File Facts

System

Linux kernel

Corpus path

tools/perf/check-header_ignore_hunks/lib/list_sort.c

Extension

.c

Size

681 bytes

Lines

25

Domain

Support Tooling And Documentation

Bucket

tools

Inferred role

Support Tooling And Documentation: implementation source

Status

source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

• Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• No C-style include directives detected by the generator.

Detected Declarations

• No top-level syscall, struct, function, initcall, or export declaration detected by the generator.

Annotated Snippet

@@ -50,6 +50,7 @@
 			struct list_head *a, struct list_head *b)
 {
 	struct list_head *tail = head;
+	u8 count = 0;
 
 	for (;;) {
 		/* if equal, take 'a' -- important for sort stability */
@@ -75,6 +76,15 @@
 	/* Finish linking remainder of list b on to tail */
 	tail->next = b;
 	do {
+		/*
+		 * If the merge is highly unbalanced (e.g. the input is
+		 * already sorted), this loop may run many iterations.
+		 * Continue callbacks to the client even though no
+		 * element comparison is needed, so the client's cmp()
+		 * routine can invoke cond_resched() periodically.
+		 */
+		if (unlikely(!++count))
+			cmp(priv, b, b);
 		b->prev = tail;
 		tail = b;
 		b = b->next;

Annotation

• Atlas domain: Support Tooling And Documentation / tools.
• Implementation status: source implementation candidate.

Implementation Notes

• This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
• Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
• Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.