From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D6DADC10F11 for ; Thu, 11 Apr 2019 01:02:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A359920850 for ; Thu, 11 Apr 2019 01:02:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726843AbfDKBCg (ORCPT ); Wed, 10 Apr 2019 21:02:36 -0400 Received: from mga05.intel.com ([192.55.52.43]:19226 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726014AbfDKBCg (ORCPT ); Wed, 10 Apr 2019 21:02:36 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 10 Apr 2019 18:02:35 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,335,1549958400"; d="scan'208";a="163237465" Received: from cli6-desk1.ccr.corp.intel.com (HELO [10.239.161.118]) ([10.239.161.118]) by fmsmga001.fm.intel.com with ESMTP; 10 Apr 2019 18:02:32 -0700 Subject: Re: [PATCH v14 1/3] /proc/pid/status: Add support for architecture specific output To: Andy Lutomirski Cc: Thomas Gleixner , Ingo Molnar , Peter Zijlstra , "H. Peter Anvin" , Andi Kleen , Tim Chen , Dave Hansen , Arjan van de Ven , Alexey Dobriyan , Andrew Morton , aubrey.li@intel.com, Linux API , LKML References: <20190410015326.24500-1-aubrey.li@linux.intel.com> <89957461-ec42-f041-a7e9-2452b2e83d39@linux.intel.com> <39318cc8-340f-5366-f1d6-e7dcbb6ba595@linux.intel.com> From: "Li, Aubrey" Message-ID: <3c2a8a1a-ed4b-348e-f06f-f71dbf64bbba@linux.intel.com> Date: Thu, 11 Apr 2019 09:02:30 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.1.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019/4/10 22:54, Andy Lutomirski wrote: > On Tue, Apr 9, 2019 at 8:40 PM Li, Aubrey wrote: >> >> On 2019/4/10 10:36, Li, Aubrey wrote: >>> On 2019/4/10 10:25, Andy Lutomirski wrote: >>>> On Tue, Apr 9, 2019 at 7:20 PM Li, Aubrey wrote: >>>>> >>>>> On 2019/4/10 9:58, Andy Lutomirski wrote: >>>>>> On Tue, Apr 9, 2019 at 6:55 PM Aubrey Li wrote: >>>>>>> >>>>>>> The architecture specific information of the running processes could >>>>>>> be useful to the userland. Add support to examine process architecture >>>>>>> specific information externally. >>>>>>> >>>>>>> Signed-off-by: Aubrey Li >>>>>>> Cc: Peter Zijlstra >>>>>>> Cc: Andi Kleen >>>>>>> Cc: Tim Chen >>>>>>> Cc: Dave Hansen >>>>>>> Cc: Arjan van de Ven >>>>>>> Cc: Linux API >>>>>>> Cc: Alexey Dobriyan >>>>>>> Cc: Andrew Morton >>>>>>> --- >>>>>>> fs/proc/array.c | 5 +++++ >>>>>>> include/linux/proc_fs.h | 2 ++ >>>>>>> 2 files changed, 7 insertions(+) >>>>>>> >>>>>>> diff --git a/fs/proc/array.c b/fs/proc/array.c >>>>>>> index 2edbb657f859..331592a61718 100644 >>>>>>> --- a/fs/proc/array.c >>>>>>> +++ b/fs/proc/array.c >>>>>>> @@ -401,6 +401,10 @@ static inline void task_thp_status(struct seq_file *m, struct mm_struct *mm) >>>>>>> seq_printf(m, "THP_enabled:\t%d\n", thp_enabled); >>>>>>> } >>>>>>> >>>>>>> +void __weak arch_proc_pid_status(struct seq_file *m, struct task_struct *task) >>>>>>> +{ >>>>>>> +} >>>>>> >>>>>> This pointlessly bloats other architectures. Do this instead in an >>>>>> appropriate header: >>>>>> >>>>>> #ifndef arch_proc_pid_status >>>>>> static inline void arch_proc_pid_status(...) >>>>>> { >>>>>> } >>>>>> #endif >>>>>> >>>>> >>>>> I saw a bunch of similar weak functions, is it not acceptable? >>>>> >>>>> fs/proc$ grep weak *.c >>>>> cpuinfo.c:__weak void arch_freq_prepare_all(void) >>>>> meminfo.c:void __attribute__((weak)) arch_report_meminfo(struct seq_file *m) >>>>> vmcore.c:int __weak elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size) >>>>> vmcore.c:void __weak elfcorehdr_free(unsigned long long addr) >>>>> vmcore.c:ssize_t __weak elfcorehdr_read(char *buf, size_t count, u64 *ppos) >>>>> vmcore.c:ssize_t __weak elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos) >>>>> vmcore.c:int __weak remap_oldmem_pfn_range(struct vm_area_struct *vma, >>>>> vmcore.c:ssize_t __weak >>>> >>>> I think they're acceptable, but I don't personally like them. >>>> >>> >>> okay, let me try to see if I can refine it in an appropriate way. >> >> Hi Andy, >> >> Is this what you want? >> >> Thanks, >> -Aubrey >> >> ==================================================================== >> diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h >> index 2bb3a648fc12..82d77d3aefff 100644 >> --- a/arch/x86/include/asm/processor.h >> +++ b/arch/x86/include/asm/processor.h >> @@ -990,5 +990,8 @@ enum l1tf_mitigations { >> }; >> >> extern enum l1tf_mitigations l1tf_mitigation; >> +/* Add support for architecture specific output in /proc/pid/status */ >> +void arch_proc_pid_status(struct seq_file *m, struct task_struct *task); >> +#define arch_proc_pid_status arch_proc_pid_status >> >> #endif /* _ASM_X86_PROCESSOR_H */ >> diff --git a/fs/proc/array.c b/fs/proc/array.c >> index 2edbb657f859..fd65a6ba2864 100644 >> --- a/fs/proc/array.c >> +++ b/fs/proc/array.c >> @@ -401,6 +401,11 @@ static inline void task_thp_status(struct seq_file *m, struct mm_struct *mm) >> seq_printf(m, "THP_enabled:\t%d\n", thp_enabled); >> } >> >> +/* Add support for architecture specific output in /proc/pid/status */ >> +#ifndef arch_proc_pid_status >> +#define arch_proc_pid_status(m, task) >> +#endif >> + >> int proc_pid_status(struct seq_file *m, struct pid_namespace *ns, >> struct pid *pid, struct task_struct *task) >> { >> @@ -424,6 +429,7 @@ int proc_pid_status(struct seq_file *m, struct pid_namespace *ns, >> task_cpus_allowed(m, task); >> cpuset_task_status_allowed(m, task); >> task_context_switch_counts(m, task); >> + arch_proc_pid_status(m, task); >> return 0; >> } >> > > Yes. But I still think it would be nicer to separate the arch stuff > into its own file. Others might reasonably disagree with me. > I like arch_status, I proposed but no other arch shows interesting in it. I think the problem is similar for x86_status, it does not make sense for those x86 platform without AVX512 to have an empty arch file. I personally don't like [arch]_status because the code may become unclean if more arches added in future. Maybe it's too early to have a separated arch staff file for now. Thanks, -Aubrey