From 9c40365a65d62d7c06a95fb331b3442cb02d2fd9 Mon Sep 17 00:00:00 2001
From: Jann Horn <jannh@google.com>
Date: Mon, 2 Mar 2020 12:29:39 +0100
Subject: threads: Update PID limit comment according to futex UAPI change
The futex UAPI changed back in commit 76b81e2b0e22 ("[PATCH] lightweight
robust futexes updates 2"), which landed in v2.6.17: FUTEX_TID_MASK is now
0x3fffffff instead of 0x1fffffff. Update the corresponding comment in
include/linux/threads.h.
Documentation mentions that only the lower 29 bits are available for TID
storage, but as the UAPI header released the bit already via
FUTEX_TID_MASK, this is moot as well. Fix it up.
[ tglx: Fixed up documentation ]
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200302112939.8068-1-jannh@google.com
---
include/linux/threads.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
(limited to 'include/linux/threads.h')
diff --git a/include/linux/threads.h b/include/linux/threads.h
index 3086dba525e2..18d5a74bcc3d 100644
--- a/include/linux/threads.h
+++ b/include/linux/threads.h
@@ -29,7 +29,7 @@
/*
* A maximum of 4 million PIDs should be enough for a while.
- * [NOTE: PID/TIDs are limited to 2^29 ~= 500+ million, see futex.h.]
+ * [NOTE: PID/TIDs are limited to 2^30 ~= 1 billion, see FUTEX_TID_MASK.]
*/
#define PID_MAX_LIMIT (CONFIG_BASE_SMALL ? PAGE_SIZE * 8 : \
(sizeof(long) > 4 ? 4 * 1024 * 1024 : PID_MAX_DEFAULT))
--
cgit