From: "Aneesh Kumar K.V" <aneesh.kumar@linux•vnet.ibm.com>
To: Paul Mackerras <paulus@ozlabs•org>
Cc: benh@kernel•crashing.org, mpe@ellerman•id.au,
linuxppc-dev@lists•ozlabs.org
Subject: Re: [PATCH V2 02/11] powerpc/mm/slice: when computing slice mask limit lowe slice max addr correctly
Date: Fri, 17 Mar 2017 12:25:37 +0530 [thread overview]
Message-ID: <87fuicfl3q.fsf@skywalker.in.ibm.com> (raw)
In-Reply-To: <20170316220304.GB10100@fergus.ozlabs.ibm.com>
Paul Mackerras <paulus@ozlabs•org> writes:
> On Thu, Mar 16, 2017 at 04:02:00PM +0530, Aneesh Kumar K.V wrote:
>> For low slice max addr should be less that 4G
> ^^^^ than
>
> A more verbose explanation of the off-by-1 error that you are fixing
> is needed here. Tell us what goes wrong with the current code and why
> your fix is the correct one.
How about
powerpc/mm/slice: when computing slice mask limit low slice max addr correctly
For low slice, max addr should be less that 4G. Without limiting this correctly
we will end up with a low slice mask which has 17th bit set. This is not
a problem with the current code because our low slice mask is of type u16. But
in later patch I am switching low slice mask to u64 type and having the 17bit
set result in wrong slice mask which in turn results in mmap failures.
>
>>
>> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux•vnet.ibm.com>
>
> For the code change:
>
> Reviewed-by: Paul Mackerras <paulus@ozlabs•org>
next prev parent reply other threads:[~2017-03-17 6:55 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-16 10:31 [PATCH V2 00/11] powerpc/mm/hash: Cleanup and fixes Aneesh Kumar K.V
2017-03-16 10:31 ` [PATCH V2 01/11] powerpc/mm/nohash: MM_SLICE is only used by book3s 64 Aneesh Kumar K.V
2017-03-16 22:00 ` Paul Mackerras
2017-03-16 10:32 ` [PATCH V2 02/11] powerpc/mm/slice: when computing slice mask limit lowe slice max addr correctly Aneesh Kumar K.V
2017-03-16 22:03 ` Paul Mackerras
2017-03-17 6:55 ` Aneesh Kumar K.V [this message]
2017-03-16 10:32 ` [PATCH V2 03/11] powerpc/mm: Cleanup bits definition between hash and radix Aneesh Kumar K.V
2017-03-16 22:16 ` Paul Mackerras
2017-03-16 10:32 ` [PATCH V2 04/11] powerpc/mm/radix: rename _PAGE_LARGE to R_PAGE_LARGE Aneesh Kumar K.V
2017-03-16 22:16 ` Paul Mackerras
2017-03-16 10:32 ` [PATCH V2 05/11] powerpc/mm: Add translation mode information in /proc/cpuinfo Aneesh Kumar K.V
2017-03-16 22:17 ` Paul Mackerras
2017-03-16 10:32 ` [PATCH V2 06/11] powerpc/mm/hugetlb: Filter out hugepage size not supported by page table layout Aneesh Kumar K.V
2017-03-16 22:19 ` Paul Mackerras
2017-03-16 10:32 ` [PATCH V2 07/11] powerpc/mm: Conditional defines of pte bits are messy Aneesh Kumar K.V
2017-03-16 22:21 ` Paul Mackerras
2017-03-16 10:32 ` [PATCH V2 08/11] powerpc/mm: Express everything based on Radix page table defines Aneesh Kumar K.V
2017-03-16 22:24 ` Paul Mackerras
2017-03-16 10:32 ` [PATCH V2 09/11] powerpc/mm: Lower the max real address to 51 bits Aneesh Kumar K.V
2017-03-16 21:26 ` Benjamin Herrenschmidt
2017-03-17 3:39 ` Aneesh Kumar K.V
2017-03-16 22:27 ` Paul Mackerras
2017-03-16 10:32 ` [PATCH V2 10/11] powerpc/mm/radix: Make max pfn bits a variable Aneesh Kumar K.V
2017-03-16 22:29 ` Paul Mackerras
2017-03-17 8:54 ` Aneesh Kumar K.V
2017-03-16 10:32 ` [PATCH V2 11/11] powerpc/mm: Move hash specific pte bits to be top bits of RPN Aneesh Kumar K.V
2017-03-16 22:34 ` Paul Mackerras
2017-03-17 3:37 ` Aneesh Kumar K.V
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