<unistd.h>: explain why getpagesize() is better than getauxval() as well as sysconf().
I thought we'd already done this, but apparently not.
Bug: http://b/315511637
Change-Id: I0581438a6f551be9750b6679a9f3ad06c83f1e9b
diff --git a/libc/include/unistd.h b/libc/include/unistd.h
index bc708e1..2552ca8 100644
--- a/libc/include/unistd.h
+++ b/libc/include/unistd.h
@@ -353,7 +353,7 @@
/**
* [getpagesize(2)](https://man7.org/linux/man-pages/man2/getpagesize.2.html)
* returns the system's page size. This is slightly faster than going via
- * sysconf().
+ * sysconf(), and avoids the linear search in getauxval().
*
* Returns the system's page size in bytes.
*/