From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rusty Russell Date: Wed, 27 May 2015 01:30:35 +0000 Subject: Re: [PATCH 06/16] ia64: fix up obsolete cpu function usage. Message-Id: <87mw0qn7h0.fsf@rustcorp.com.au> List-Id: References: <1425296150-4722-1-git-send-email-rusty@rustcorp.com.au> <1425296150-4722-6-git-send-email-rusty@rustcorp.com.au> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Tony Luck Cc: Linux Kernel Mailing List , Fenghua Yu , "linux-ia64@vger.kernel.org" Tony Luck writes: > On Mon, Mar 2, 2015 at 3:35 AM, Rusty Russell wrote: >> Thanks to spatch, then a sweep for for_each_cpu_mask => for_each_cpu. >> >> Signed-off-by: Rusty Russell > > I'm seeing a bunch of warnings building the ia64 tree: Indeed, here's the forgotten fix sitting in my patch collection. > Should cpumask_set_cpu() and friends specify a volatile argument??? It's weird, but it turns out hardly anyone wants that. Cheers, Rusty. ia64: make cpu_callin_map non-volatile. cpumask_test_cpu() doesn't take volatile, unlike the obsoleted cpu_isset. The only place ia64 really cares is the spin waiting for a bit; udelay() is probably a barrier but insert rmb() to be sure. Signed-off-by: Rusty Russell diff --git a/arch/ia64/kernel/smpboot.c b/arch/ia64/kernel/smpboot.c index 15051e9c2c6f..629975b56608 100644 --- a/arch/ia64/kernel/smpboot.c +++ b/arch/ia64/kernel/smpboot.c @@ -127,7 +127,7 @@ int smp_num_siblings = 1; volatile int ia64_cpu_to_sapicid[NR_CPUS]; EXPORT_SYMBOL(ia64_cpu_to_sapicid); -static volatile cpumask_t cpu_callin_map; +static cpumask_t cpu_callin_map; struct smp_boot_data smp_boot_data __initdata; @@ -477,6 +477,7 @@ do_boot_cpu (int sapicid, int cpu, struct task_struct *idle) for (timeout = 0; timeout < 100000; timeout++) { if (cpumask_test_cpu(cpu, &cpu_callin_map)) break; /* It has booted */ + rmb(); /* Make sure we re-read cpu_callin_map */ udelay(100); } Dprintk("\n");