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From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
To: Christophe Leroy <christophe.leroy@c-s.fr>,
	npiggin@gmail.com, benh@kernel.crashing.org, paulus@samba.org,
	mpe@ellerman.id.au
Cc: linuxppc-dev@lists.ozlabs.org
Subject: Re: [RFC PATCH] powerpc/mm: Reduce memory usage for mm_context_t for radix
Date: Tue, 2 Apr 2019 21:12:03 +0530	[thread overview]
Message-ID: <200e5a1a-9475-8d43-666c-1845f9d95d1b@linux.ibm.com> (raw)
In-Reply-To: <80f34a0e-2bbe-8751-6571-3f844103fc37@c-s.fr>

On 4/2/19 9:06 PM, Christophe Leroy wrote:
> 
> 
> Le 02/04/2019 à 16:34, Aneesh Kumar K.V a écrit :
>> Currently, our mm_context_t on book3s64 include all hash specific
>> context details like slice mask, subpage protection details. We
>> can skip allocating those on radix. This will help us to save
>> 8K per mm_context with radix translation.
>>
>> With the patch applied we have
>>
>> sizeof(mm_context_t)  = 136
>> sizeof(struct hash_mm_context)  = 8288
>>
>> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
>> ---
>> NOTE:
>>
>> If we want to do this, I am still trying to figure out how best we can 
>> do this
>> without all the #ifdef and other overhead for 8xx book3e
> 
> Did you have a look at my series 
> https://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=98170 ?
> 
> It tries to reduce as much as feasible the #ifdefs and stuff.
> 
>

Not yet. But a cursory look tell me introducing hash_mm_context 
complicates this further unless I introduce something similar for nohash 
32? Are you ok with that?

-aneesh


  reply	other threads:[~2019-04-02 15:43 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-02 14:34 [RFC PATCH] powerpc/mm: Reduce memory usage for mm_context_t for radix Aneesh Kumar K.V
2019-04-02 15:36 ` Christophe Leroy
2019-04-02 15:42   ` Aneesh Kumar K.V [this message]
2019-04-02 18:34     ` Christophe Leroy
2019-04-02 18:31 ` Christophe Leroy
2019-04-02 18:37   ` Christophe Leroy
2019-04-04 16:13   ` Nicholas Piggin
2019-04-04 16:55     ` Christophe Leroy

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