From: Chintan Pandya <cpandya@codeaurora.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH v2] mm: BUG when __kmap_atomic_idx equals KM_TYPE_NR
Date: Mon, 04 Aug 2014 14:55:24 +0530 [thread overview]
Message-ID: <53DF5184.1040501@codeaurora.org> (raw)
In-Reply-To: <20140731154540.441ab79ff32ae5c10f64bcbd@linux-foundation.org>
On 08/01/2014 04:15 AM, Andrew Morton wrote:
> On Thu, 31 Jul 2014 14:58:58 +0530 Chintan Pandya<cpandya@codeaurora.org> wrote:
>
>>>
>>> I think Andrew's comment earlier was referring to the changelog only and
>>> not the patch, which looked correct.
>>
>> I think Andrew asked for a BUG case details also to justify the
>> overhead. But we have never encountered that BUG case. Present patch is
>> only logical fix to the code. However, in the fast path, if such
>> overhead is allowed, I can move BUG_ON out of any debug configs.
>> Otherwise, as per Andrew's suggestion, I will convert DEBUG_HIGHMEM into
>> DEBUG_VM which is used more frequently.
>
> The v1 patch added a small amount of overhead to kmap_atomic() for what
> is evidently a very small benefit.
>
> Yes, I suggest we remove CONFIG_DEBUG_HIGHMEM from the kernel entirely
> and switch all CONFIG_DEBUG_HIGHMEM sites to use CONFIG_DEBUG_VM. That way
> the BUG_ON which you believe is useful will be tested by more people
> more often.
Ping!! Anything open for me to do here ?
--
Chintan Pandya
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a
member of the Code Aurora Forum, hosted by The Linux Foundation
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WARNING: multiple messages have this Message-ID (diff)
From: Chintan Pandya <cpandya@codeaurora.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH v2] mm: BUG when __kmap_atomic_idx equals KM_TYPE_NR
Date: Mon, 04 Aug 2014 14:55:24 +0530 [thread overview]
Message-ID: <53DF5184.1040501@codeaurora.org> (raw)
In-Reply-To: <20140731154540.441ab79ff32ae5c10f64bcbd@linux-foundation.org>
On 08/01/2014 04:15 AM, Andrew Morton wrote:
> On Thu, 31 Jul 2014 14:58:58 +0530 Chintan Pandya<cpandya@codeaurora.org> wrote:
>
>>>
>>> I think Andrew's comment earlier was referring to the changelog only and
>>> not the patch, which looked correct.
>>
>> I think Andrew asked for a BUG case details also to justify the
>> overhead. But we have never encountered that BUG case. Present patch is
>> only logical fix to the code. However, in the fast path, if such
>> overhead is allowed, I can move BUG_ON out of any debug configs.
>> Otherwise, as per Andrew's suggestion, I will convert DEBUG_HIGHMEM into
>> DEBUG_VM which is used more frequently.
>
> The v1 patch added a small amount of overhead to kmap_atomic() for what
> is evidently a very small benefit.
>
> Yes, I suggest we remove CONFIG_DEBUG_HIGHMEM from the kernel entirely
> and switch all CONFIG_DEBUG_HIGHMEM sites to use CONFIG_DEBUG_VM. That way
> the BUG_ON which you believe is useful will be tested by more people
> more often.
Ping!! Anything open for me to do here ?
--
Chintan Pandya
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a
member of the Code Aurora Forum, hosted by The Linux Foundation
next prev parent reply other threads:[~2014-08-04 9:25 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-31 6:24 [PATCH v2] mm: BUG when __kmap_atomic_idx equals KM_TYPE_NR Chintan Pandya
2014-07-31 6:24 ` Chintan Pandya
2014-07-31 7:02 ` David Rientjes
2014-07-31 7:02 ` David Rientjes
2014-07-31 9:28 ` Chintan Pandya
2014-07-31 9:28 ` Chintan Pandya
2014-07-31 22:45 ` Andrew Morton
2014-07-31 22:45 ` Andrew Morton
2014-08-04 9:25 ` Chintan Pandya [this message]
2014-08-04 9:25 ` Chintan Pandya
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