Re: [PATCH v2] ring-buffer: Never use absolute timestamp for first event

2023-12-12 Thread Steven Rostedt
On Tue, 12 Dec 2023 23:20:08 +0900 Masami Hiramatsu (Google) wrote: > On Tue, 12 Dec 2023 07:18:37 -0500 > Steven Rostedt wrote: > > > From: "Steven Rostedt (Google)" > > > > On 32bit machines, the 64 bit timestamps are broken up into 32 bit words > > to keep from using local64_cmpxchg(), as

Re: [PATCH v2] ring-buffer: Never use absolute timestamp for first event

2023-12-12 Thread Google
On Tue, 12 Dec 2023 07:18:37 -0500 Steven Rostedt wrote: > From: "Steven Rostedt (Google)" > > On 32bit machines, the 64 bit timestamps are broken up into 32 bit words > to keep from using local64_cmpxchg(), as that is very expensive on 32 bit > architectures. > > On 32 bit architectures, read

[PATCH v2] ring-buffer: Never use absolute timestamp for first event

2023-12-12 Thread Steven Rostedt
From: "Steven Rostedt (Google)" On 32bit machines, the 64 bit timestamps are broken up into 32 bit words to keep from using local64_cmpxchg(), as that is very expensive on 32 bit architectures. On 32 bit architectures, reading these timestamps can happen in a middle of an update. In this case, t