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[198.145.64.163]) by smtp.gmail.com with ESMTPSA id t1sm234626pfe.61.2021.06.02.10.46.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 02 Jun 2021 10:46:13 -0700 (PDT) Date: Wed, 2 Jun 2021 10:46:12 -0700 From: Kees Cook To: Eric Dumazet Cc: Ingo Molnar , linux-kernel , Eric Dumazet , Josh Poimboeuf , Peter Zijlstra , Dan Williams , Guenter Roeck Subject: Re: [PATCH] sched/debug: remove obsolete init_schedstats() Message-ID: <202106021045.7C51D37@keescook> References: <20210602112108.1709635-1-eric.dumazet@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210602112108.1709635-1-eric.dumazet@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 02, 2021 at 04:21:08AM -0700, Eric Dumazet wrote: > From: Eric Dumazet > > Revert "sched/debug: Fix 'schedstats=enable' cmdline option" > > This reverts commit 4698f88c06b893f2acc0b443004a53bf490fde7c. > > After commit 6041186a3258 ("init: initialize jump labels before command > line option parsing") we can rely on jump label infra being ready for use > when setup_schedstats() is called. Ah yeah, good catch. Reviewed-by: Kees Cook -Kees > > Signed-off-by: Eric Dumazet > Cc: Josh Poimboeuf > Cc: Peter Zijlstra (Intel) > Cc: Ingo Molnar > Cc: Dan Williams > Cc: Guenter Roeck > Cc: Kees Cook > --- > kernel/sched/core.c | 19 ++----------------- > 1 file changed, 2 insertions(+), 17 deletions(-) > > diff --git a/kernel/sched/core.c b/kernel/sched/core.c > index 5226cc26a095f427dafa864ff37d39d529e2ba85..105fa6c73e7d9ded05683ee43a11e3b4461932d5 100644 > --- a/kernel/sched/core.c > +++ b/kernel/sched/core.c > @@ -3648,7 +3648,6 @@ int sysctl_numa_balancing(struct ctl_table *table, int write, > #ifdef CONFIG_SCHEDSTATS > > DEFINE_STATIC_KEY_FALSE(sched_schedstats); > -static bool __initdata __sched_schedstats = false; > > static void set_schedstats(bool enabled) > { > @@ -3672,16 +3671,11 @@ static int __init setup_schedstats(char *str) > if (!str) > goto out; > > - /* > - * This code is called before jump labels have been set up, so we can't > - * change the static branch directly just yet. Instead set a temporary > - * variable so init_schedstats() can do it later. > - */ > if (!strcmp(str, "enable")) { > - __sched_schedstats = true; > + set_schedstats(true); > ret = 1; > } else if (!strcmp(str, "disable")) { > - __sched_schedstats = false; > + set_schedstats(false); > ret = 1; > } > out: > @@ -3692,11 +3686,6 @@ static int __init setup_schedstats(char *str) > } > __setup("schedstats=", setup_schedstats); > > -static void __init init_schedstats(void) > -{ > - set_schedstats(__sched_schedstats); > -} > - > #ifdef CONFIG_PROC_SYSCTL > int sysctl_schedstats(struct ctl_table *table, int write, void *buffer, > size_t *lenp, loff_t *ppos) > @@ -3718,8 +3707,6 @@ int sysctl_schedstats(struct ctl_table *table, int write, void *buffer, > return err; > } > #endif /* CONFIG_PROC_SYSCTL */ > -#else /* !CONFIG_SCHEDSTATS */ > -static inline void init_schedstats(void) {} > #endif /* CONFIG_SCHEDSTATS */ > > /* > @@ -8258,8 +8245,6 @@ void __init sched_init(void) > #endif > init_sched_fair_class(); > > - init_schedstats(); > - > psi_init(); > > init_uclamp(); > -- > 2.32.0.rc0.204.g9fa02ecfa5-goog > -- Kees Cook