linux-kernel - Re: [PATCH v2 05/12] perf/x86: add cross-HT counter exclusion infrastructure

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CABPqkBTim1nHhF2zEm0FGLBVStuD1TvdH_gifP+f3GCxdMp4Ag@mail.gmail.com>
Date:	Wed, 22 Oct 2014 19:25:40 +0200
From:	Stephane Eranian <eranian@...gle.com>
To:	Jiri Olsa <jolsa@...hat.com>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	Peter Zijlstra <peterz@...radead.org>,
	"mingo@...e.hu" <mingo@...e.hu>,
	"ak@...ux.intel.com" <ak@...ux.intel.com>,
	"Liang, Kan" <kan.liang@...el.com>, Borislav Petkov <bp@...en8.de>,
	Maria Dimakopoulou <maria.n.dimakopoulou@...il.com>
Subject: Re: [PATCH v2 05/12] perf/x86: add cross-HT counter exclusion infrastructure

On Wed, Oct 22, 2014 at 5:07 PM, Jiri Olsa <jolsa@...hat.com> wrote:
> On Thu, Oct 09, 2014 at 06:34:39PM +0200, Stephane Eranian wrote:
>> From: Maria Dimakopoulou <maria.n.dimakopoulou@...il.com>
>>
>
> SNIP
>
>> +struct intel_excl_cntrs *allocate_excl_cntrs(int cpu)
>> +{
>> +     struct intel_excl_cntrs *c;
>> +     int i;
>> +
>> +     c = kzalloc_node(sizeof(struct intel_excl_cntrs),
>> +                      GFP_KERNEL, cpu_to_node(cpu));
>> +     if (c) {
>> +             spin_lock_init(&c->lock);
>> +             for (i = 0; i < X86_PMC_IDX_MAX; i++) {
>> +                     c->states[0].state[i] = INTEL_EXCL_UNUSED;
>> +                     c->states[0].init_state[i] = INTEL_EXCL_UNUSED;
>> +
>> +                     c->states[1].state[i] = INTEL_EXCL_UNUSED;
>> +                     c->states[1].init_state[i] = INTEL_EXCL_UNUSED;
>
> 'c' is allocated with kzalloc_node, seems there's no need
> to re-initialize states it to zero again with INTEL_EXCL_UNUSED
>
You are assuming that INTEL_EXCL_UNUSED=0 always.
That means it needs to be clear there is a dependency here.

I am happy removing that if someone confirms the assumption is common
in the kernel
for this kind of fields.


> jirka
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/