From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Weiner Subject: Re: [PATCH 1/2] sched/psi: simplify cgroup psi retrieving Date: Wed, 8 Feb 2023 13:54:54 -0500 Message-ID: References: <20230208161654.99556-1-ryncsn@gmail.com> <20230208161654.99556-2-ryncsn@gmail.com> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20210112.gappssmtp.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=h8wnkAyp+UT+1C4mbuuq7uAJNtmK6LABMEs9ejaKbmU=; b=D6besAl+jnXs8HL2wgkgbCj2qj3xJ9fr/H/QmgZCQOBl/ILNdsAnYnJz5z/T00IMUS 0LjcTtS5QnJ0TqPgeMn3odKFuB1k7RURDlftGvJvo+M0cbC8W/TgfGGWUivhjQ02WfAL hH75lKyYjyXVvWK2I9cGrN8jkuWCEJxrLFUCUo6h3+mPqU280HNWG2VzpHjmXqrErVPu Dvuhm6cqJup7Slw5HCYXzdphjvFgXJpe5kkkWwrtB1WN9BwLThsX9bBAvaqbN9Rjn+Jw f/6Y7vKq4zhEWwPwKJou0IwNH/fOmSvBArEMpJLpctVxM0xtJhSKz1GfOfQpL+/c/kB1 srYw== Content-Disposition: inline In-Reply-To: <20230208161654.99556-2-ryncsn-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Kairui Song Cc: Suren Baghdasaryan , Chengming Zhou , Michal =?iso-8859-1?Q?Koutn=FD?= , Tejun Heo , Ingo Molnar , Peter Zijlstra , cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Kairui Song Hello Kairui, On Thu, Feb 09, 2023 at 12:16:53AM +0800, Kairui Song wrote: > From: Kairui Song > > Since the only case where cgroup_psi should return psi_system instead of > the cgroup's psi_group is the root cgroup, just set root cgroup's psi to > point to psi_system to remove the if branch. > > Signed-off-by: Kairui Song Thanks for the patches. They overall look good, and the numbers even better. > include/linux/psi.h | 2 +- > kernel/cgroup/cgroup.c | 7 ++++++- > 2 files changed, 7 insertions(+), 2 deletions(-) > > diff --git a/include/linux/psi.h b/include/linux/psi.h > index b029a847def1..9c3a1638b618 100644 > --- a/include/linux/psi.h > +++ b/include/linux/psi.h > @@ -33,7 +33,7 @@ __poll_t psi_trigger_poll(void **trigger_ptr, struct file *file, > #ifdef CONFIG_CGROUPS > static inline struct psi_group *cgroup_psi(struct cgroup *cgrp) > { > - return cgroup_ino(cgrp) == 1 ? &psi_system : cgrp->psi; > + return cgrp->psi; > } > > int psi_cgroup_alloc(struct cgroup *cgrp); > diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c > index c099cf3fa02d..1491d63b06b6 100644 > --- a/kernel/cgroup/cgroup.c > +++ b/kernel/cgroup/cgroup.c > @@ -163,7 +163,12 @@ static struct static_key_true *cgroup_subsys_on_dfl_key[] = { > static DEFINE_PER_CPU(struct cgroup_rstat_cpu, cgrp_dfl_root_rstat_cpu); > > /* the default hierarchy */ > -struct cgroup_root cgrp_dfl_root = { .cgrp.rstat_cpu = &cgrp_dfl_root_rstat_cpu }; > +struct cgroup_root cgrp_dfl_root = { > + .cgrp.rstat_cpu = &cgrp_dfl_root_rstat_cpu, > +#ifdef CONFIG_PSI > + .cgrp.psi = &psi_system > +#endif Nitpick: customary coding style is to keep a comma even after the last entry in the struct. Somebody appending new things won't need to touch the previous last line, which adds diff noise. With that, please add: Acked-by: Johannes Weiner