Re: [PATCH 1/3] rseq: optimize rseq_update_cpu_id()

2021-04-13 Thread Eric Dumazet
On Tue, Apr 13, 2021 at 4:29 PM Mathieu Desnoyers wrote: > > - On Apr 13, 2021, at 3:36 AM, Eric Dumazet eric.duma...@gmail.com wrote: > > > From: Eric Dumazet > > > > Two put_user() in rseq_update_cpu_id() are replaced > > by a pair of unsafe_put_user() with appropriate surroundings. > > >

Re: [PATCH 1/3] rseq: optimize rseq_update_cpu_id()

2021-04-13 Thread Mathieu Desnoyers
- On Apr 13, 2021, at 3:36 AM, Eric Dumazet eric.duma...@gmail.com wrote: > From: Eric Dumazet > > Two put_user() in rseq_update_cpu_id() are replaced > by a pair of unsafe_put_user() with appropriate surroundings. > > This removes one stac/clac pair on x86 in fast path. > >

[PATCH 1/3] rseq: optimize rseq_update_cpu_id()

2021-04-13 Thread Eric Dumazet
From: Eric Dumazet Two put_user() in rseq_update_cpu_id() are replaced by a pair of unsafe_put_user() with appropriate surroundings. This removes one stac/clac pair on x86 in fast path. Signed-off-by: Eric Dumazet Cc: Mathieu Desnoyers Cc: Peter Zijlstra Cc: "Paul E. McKenney" Cc: Boqun