Re: [PATCH 0/24] make atomic_read() behave consistently across all architectures
From: Christoph Lameter <hidden>
Date: 2007-08-14 23:14:38
Also in:
linux-arch, lkml
On Tue, 14 Aug 2007, Chris Snook wrote:
Because atomic operations are generally used for synchronization, which requires volatile behavior. Most such codepaths currently use an inefficient barrier(). Some forget to and we get bugs, because people assume that atomic_read() actually reads something, and atomic_write() actually writes something. Worse, these are architecture-specific, even compiler version-specific bugs that are often difficult to track down.
Looks like we need to have lock and unlock semantics? atomic_read() which has no barrier or volatile implications. atomic_read_for_lock Acquire semantics? atomic_read_for_unlock Release semantics?