From: Waiman Long Date: Tue, 7 Jan 2020 17:49:14 +0000 (-0500) Subject: locking/qspinlock: Fix inaccessible URL of MCS lock paper X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=57097124cbbd310cc2b5884189e22e60a3c20514;p=linux.git locking/qspinlock: Fix inaccessible URL of MCS lock paper It turns out that the URL of the MCS lock paper listed in the source code is no longer accessible. I did got question about where the paper was. This patch updates the URL to BZ 206115 which contains a copy of the paper from https://www.cs.rochester.edu/u/scott/papers/1991_TOCS_synch.pdf Signed-off-by: Waiman Long Signed-off-by: Peter Zijlstra (Intel) Acked-by: Will Deacon Link: https://lkml.kernel.org/r/20200107174914.4187-1-longman@redhat.com --- diff --git a/kernel/locking/qspinlock.c b/kernel/locking/qspinlock.c index 2473f10c6956a..b9515fcc9b297 100644 --- a/kernel/locking/qspinlock.c +++ b/kernel/locking/qspinlock.c @@ -31,14 +31,15 @@ /* * The basic principle of a queue-based spinlock can best be understood * by studying a classic queue-based spinlock implementation called the - * MCS lock. The paper below provides a good description for this kind - * of lock. + * MCS lock. A copy of the original MCS lock paper ("Algorithms for Scalable + * Synchronization on Shared-Memory Multiprocessors by Mellor-Crummey and + * Scott") is available at * - * http://www.cise.ufl.edu/tr/DOC/REP-1992-71.pdf + * https://bugzilla.kernel.org/show_bug.cgi?id=206115 * - * This queued spinlock implementation is based on the MCS lock, however to make - * it fit the 4 bytes we assume spinlock_t to be, and preserve its existing - * API, we must modify it somehow. + * This queued spinlock implementation is based on the MCS lock, however to + * make it fit the 4 bytes we assume spinlock_t to be, and preserve its + * existing API, we must modify it somehow. * * In particular; where the traditional MCS lock consists of a tail pointer * (8 bytes) and needs the next pointer (another 8 bytes) of its own node to