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From: Bart Van Assche <Bart.VanAssche@wdc.com>
To: "yang.s@alibaba-inc.com" <yang.s@alibaba-inc.com>,
	"akpm@linux-foundation.org" <akpm@linux-foundation.org>
Cc: "joe@perches.com" <joe@perches.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>,
	"mhocko@kernel.org" <mhocko@kernel.org>,
	"mingo@redhat.com" <mingo@redhat.com>
Subject: Re: [PATCH] mm: use in_atomic() in print_vma_addr()
Date: Fri, 3 Nov 2017 20:09:49 +0000	[thread overview]
Message-ID: <1509739786.2473.33.camel@wdc.com> (raw)
In-Reply-To: <20171103110245.7049460a05cc18c7e8a9feb2@linux-foundation.org>

On Fri, 2017-11-03 at 11:02 -0700, Andrew Morton wrote:
> Also, checkpatch says
> 
> WARNING: use of in_atomic() is incorrect outside core kernel code
> #43: FILE: mm/memory.c:4491:
> +       if (in_atomic())
> 
> I don't recall why we did that, but perhaps this should be revisited?

Is the comment above in_atomic() still up-to-date? From <linux/preempt.h>:

/*
 * Are we running in atomic context?  WARNING: this macro cannot
 * always detect atomic context; in particular, it cannot know about
 * held spinlocks in non-preemptible kernels.  Thus it should not be
 * used in the general case to determine whether sleeping is possible.
 * Do not use in_atomic() in driver code.
 */
#define in_atomic()	(preempt_count() != 0)

Bart.

WARNING: multiple messages have this Message-ID (diff)
From: Bart Van Assche <Bart.VanAssche@wdc.com>
To: "yang.s@alibaba-inc.com" <yang.s@alibaba-inc.com>,
	"akpm@linux-foundation.org" <akpm@linux-foundation.org>
Cc: "joe@perches.com" <joe@perches.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>,
	"mhocko@kernel.org" <mhocko@kernel.org>,
	"mingo@redhat.com" <mingo@redhat.com>
Subject: Re: [PATCH] mm: use in_atomic() in print_vma_addr()
Date: Fri, 3 Nov 2017 20:09:49 +0000	[thread overview]
Message-ID: <1509739786.2473.33.camel@wdc.com> (raw)
In-Reply-To: <20171103110245.7049460a05cc18c7e8a9feb2@linux-foundation.org>

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[-- Attachment #1: Type: text/plain; charset="utf-8", Size: 852 bytes --]

On Fri, 2017-11-03 at 11:02 -0700, Andrew Morton wrote:
> Also, checkpatch says
> 
> WARNING: use of in_atomic() is incorrect outside core kernel code
> #43: FILE: mm/memory.c:4491:
> +       if (in_atomic())
> 
> I don't recall why we did that, but perhaps this should be revisited?

Is the comment above in_atomic() still up-to-date? From <linux/preempt.h>:

/*
 * Are we running in atomic context?  WARNING: this macro cannot
 * always detect atomic context; in particular, it cannot know about
 * held spinlocks in non-preemptible kernels.  Thus it should not be
 * used in the general case to determine whether sleeping is possible.
 * Do not use in_atomic() in driver code.
 */
#define in_atomic()	(preempt_count() != 0)

Bart.N‹§²æìr¸›zǧu©ž²Æ {\b­†éì¹»\x1c®&Þ–)îÆi¢žØ^n‡r¶‰šŽŠÝ¢j$½§$¢¸\x05¢¹¨­è§~Š'.)îÄÃ,yèm¶ŸÿÃ\f%Š{±šj+ƒðèž×¦j)Z†·Ÿ

  parent reply	other threads:[~2017-11-03 20:09 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-11-01 21:38 [PATCH] mm: use in_atomic() in print_vma_addr() Yang Shi
2017-11-01 21:38 ` Yang Shi
2017-11-02  7:57 ` Michal Hocko
2017-11-02  7:57   ` Michal Hocko
2017-11-02 17:44   ` Yang Shi
2017-11-02 17:44     ` Yang Shi
2017-11-03  8:29     ` Michal Hocko
2017-11-03  8:29       ` Michal Hocko
2017-11-03 18:02     ` Andrew Morton
2017-11-03 18:02       ` Andrew Morton
2017-11-03 18:16       ` Yang Shi
2017-11-03 18:16         ` Yang Shi
2017-11-03 20:09       ` Bart Van Assche [this message]
2017-11-03 20:09         ` Bart Van Assche
2017-11-05  8:19         ` Michal Hocko
2017-11-05  8:19           ` Michal Hocko
2017-11-06 10:05           ` Peter Zijlstra
2017-11-06 10:05             ` Peter Zijlstra
2017-11-06 10:43             ` Michal Hocko
2017-11-06 10:43               ` Michal Hocko
2017-11-06 10:56               ` Michal Hocko
2017-11-06 10:56                 ` Michal Hocko
2017-11-06 12:00               ` Peter Zijlstra
2017-11-06 12:00                 ` Peter Zijlstra
2017-11-06 12:12                 ` Michal Hocko
2017-11-06 12:12                   ` Michal Hocko
2017-11-06 13:40                   ` [PATCH] mm: do not rely on preempt_count in print_vma_addr (was: Re: [PATCH] mm: use in_atomic() in print_vma_addr()) Michal Hocko
2017-11-06 13:40                     ` Michal Hocko
2017-11-06 14:19                     ` [PATCH] mm: do not rely on preempt_count in print_vma_addr Vlastimil Babka
2017-11-06 14:19                       ` Vlastimil Babka
2017-11-06 14:28                       ` Michal Hocko
2017-11-06 14:28                         ` Michal Hocko
2017-11-06 16:16                     ` Yang Shi
2017-11-06 16:16                       ` Yang Shi
2017-11-06 16:24                       ` Michal Hocko
2017-11-06 16:24                         ` Michal Hocko

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