Re: [PATCH v2 1/4] sched/isolation: API to get housekeeping online CPUs

2020-09-24 Thread peterz
On Wed, Sep 23, 2020 at 02:11:23PM -0400, Nitesh Narayan Lal wrote: > Introduce a new API hk_num_online_cpus(), that can be used to > retrieve the number of online housekeeping CPUs that are meant to handle > managed IRQ jobs. > > This API is introduced for the drivers that were previously relying

Re: possible deadlock in xfrm_policy_delete

2020-09-24 Thread peterz
On Thu, Sep 24, 2020 at 06:44:12AM +0200, Dmitry Vyukov wrote: > On Thu, Sep 24, 2020 at 6:36 AM Herbert Xu > wrote: > > > (k-slock-AF_INET6){+.-.}-{2:2} That's a seqlock. > > What's going on with all these bogus lockdep reports? > > > > These are two completely different locks, one is for TCP

Re: [PATCH net-next 6/7] lockdep: provide dummy forward declaration of *_is_held() helpers

2020-09-17 Thread peterz
On Wed, Sep 16, 2020 at 11:45:27AM -0700, Jakub Kicinski wrote: > When CONFIG_LOCKDEP is not set, lock_is_held() and lockdep_is_held() > are not declared or defined. This forces all callers to use ifdefs > around these checks. > > Recent RCU changes added a lot of lockdep_is_held() calls inside >

Re: [PATCH] random32: Use rcuidle variant for tracepoint

2020-08-21 Thread peterz
On Fri, Aug 21, 2020 at 08:30:43AM +0200, Marco Elver wrote: > With KCSAN enabled, prandom_u32() may be called from any context, > including idle CPUs. > > Therefore, switch to using trace_prandom_u32_rcuidle(), to avoid various > issues due to recursion and lockdep warnings when KCSAN and tracing

Re: [PATCH net] net: accept an empty mask in /sys/class/net/*/queues/rx-*/rps_cpus

2020-08-12 Thread peterz
On Tue, Aug 11, 2020 at 06:45:23PM -0700, Maciej Żenczykowski wrote: > On Tue, Aug 11, 2020 at 6:34 PM Eric Dumazet wrote: > > > We must accept an empty mask in store_rps_map(), or we are not able > > to disable RPS on a queue. > > > > Fixes: 07bbecb34106 ("net: Restrict receive packets queuing t

Re: [PATCH 2/5] seqlock: Fold seqcount_LOCKNAME_t definition

2020-07-29 Thread peterz
On Wed, Jul 29, 2020 at 05:33:41PM +0200, pet...@infradead.org wrote: > On Wed, Jul 29, 2020 at 03:55:07PM +0100, Matthew Wilcox wrote: > > On Wed, Jul 29, 2020 at 03:52:51PM +0200, Peter Zijlstra wrote: > > > Manual repetition is boring and error prone. > > > > Yes, but generated functions are ha

Re: [PATCH 2/5] seqlock: Fold seqcount_LOCKNAME_t definition

2020-07-29 Thread peterz
On Wed, Jul 29, 2020 at 03:55:07PM +0100, Matthew Wilcox wrote: > On Wed, Jul 29, 2020 at 03:52:51PM +0200, Peter Zijlstra wrote: > > Manual repetition is boring and error prone. > > Yes, but generated functions are hard to grep for, and I'm pretty sure > that kernel-doc doesn't know how to expand