On Tue, May 19, 2020 at 11:45:31PM +0200, Ahmed S. Darwish wrote: > diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h > index d35be7709403..2a4af746b1da 100644 > --- a/include/linux/seqlock.h > +++ b/include/linux/seqlock.h > @@ -1,36 +1,15 @@ > /* SPDX-License-Identifier: GPL-2.0 */ > #ifndef __LINUX_SEQLOCK_H > #define __LINUX_SEQLOCK_H > + > /* > - * Reader/writer consistent mechanism without starving writers. This type of > - * lock for data where the reader wants a consistent set of information > - * and is willing to retry if the information changes. There are two types > - * of readers: > - * 1. Sequence readers which never block a writer but they may have to retry > - * if a writer is in progress by detecting change in sequence number. > - * Writers do not wait for a sequence reader. > - * 2. Locking readers which will wait if a writer or another locking reader > - * is in progress. A locking reader in progress will also block a writer > - * from going forward. Unlike the regular rwlock, the read lock here is > - * exclusive so that only one locking reader can get it. > + * seqcount_t / seqlock_t - a reader-writer consistency mechanism with > + * lockless readers (read-only retry loops), and no writer starvation. > * > - * This is not as cache friendly as brlock. Also, this may not work well > - * for data that contains pointers, because any writer could > - * invalidate a pointer that a reader was following. > + * See Documentation/locking/seqlock.rst for full description. So I really really hate that... I _much_ prefer code comments to crappy documents.
