x86/alternatives: Document 'smp_text_poke_single()'

Extend the documentation to better describe its purpose.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250411054105.2341982-38-mingo@kernel.org

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index f0bb2158f27b75f97341fbc72f05762f62a5db7c..a9726cc9697221c81ebea0f264b9f9dd3c12843b 100644 (file)
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -2880,7 +2880,7 @@ void __ref smp_text_poke_batch_add(void *addr, const void *opcode, size_t len, c
 }
 
 /**
- * smp_text_poke_single() -- update instructions on live kernel on SMP
+ * smp_text_poke_single() -- update instruction on live kernel on SMP immediately
  * @addr:      address to patch
  * @opcode:    opcode of new instruction
  * @len:       length to copy
@@ -2888,7 +2888,8 @@ void __ref smp_text_poke_batch_add(void *addr, const void *opcode, size_t len, c
  *
  * Update a single instruction with the vector in the stack, avoiding
  * dynamically allocated memory. This function should be used when it is
- * not possible to allocate memory.
+ * not possible to allocate memory for a vector. The single instruction
+ * is patched in immediately.
  */
 void __ref smp_text_poke_single(void *addr, const void *opcode, size_t len, const void *emulate)
 {