* Re: linux-next: Tree for May 13 (mm/page_alloc.c, <linux/mm.h>: sizeof(struct page))
[not found] <20210513154418.2946f422@canb.auug.org.au>
@ 2021-05-13 17:29 ` Randy Dunlap
2021-05-13 21:27 ` Matthew Wilcox
0 siblings, 1 reply; 4+ messages in thread
From: Randy Dunlap @ 2021-05-13 17:29 UTC (permalink / raw)
To: Stephen Rothwell, Linux Next Mailing List
Cc: Linux Kernel Mailing List, Alexander Duyck, Andrew Morton, Linux MM
[-- Attachment #1: Type: text/plain, Size: 1541 bytes --]
On 5/12/21 10:44 PM, Stephen Rothwell wrote:
> Hi all,
>
> Changes since 20210512:
>
on x86_64:
In function ‘__mm_zero_struct_page.isra.75’,
inlined from ‘__init_single_page.isra.76’ at ../mm/page_alloc.c:1494:2:
./../include/linux/compiler_types.h:328:38: error: call to ‘__compiletime_assert_162’ declared with attribute error: BUILD_BUG_ON failed: sizeof(struct page) > 80
_compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
^
./../include/linux/compiler_types.h:309:4: note: in definition of macro ‘__compiletime_assert’
prefix ## suffix(); \
^~~~~~
./../include/linux/compiler_types.h:328:2: note: in expansion of macro ‘_compiletime_assert’
_compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
^~~~~~~~~~~~~~~~~~~
../include/linux/build_bug.h:39:37: note: in expansion of macro ‘compiletime_assert’
#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
^~~~~~~~~~~~~~~~~~
../include/linux/build_bug.h:50:2: note: in expansion of macro ‘BUILD_BUG_ON_MSG’
BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
^~~~~~~~~~~~~~~~
../include/linux/mm.h:169:2: note: in expansion of macro ‘BUILD_BUG_ON’
BUILD_BUG_ON(sizeof(struct page) > 80);
^~~~~~~~~~~~
Full randconfig file is attached.
$ gcc --version
gcc (SUSE Linux) 7.5.0
--
~Randy
Reported-by: Randy Dunlap <rdunlap@infradead.org>
[-- Attachment #2: config-r9309.gz --]
[-- Type: application/gzip, Size: 25479 bytes --]
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: linux-next: Tree for May 13 (mm/page_alloc.c, <linux/mm.h>: sizeof(struct page))
2021-05-13 17:29 ` linux-next: Tree for May 13 (mm/page_alloc.c, <linux/mm.h>: sizeof(struct page)) Randy Dunlap
@ 2021-05-13 21:27 ` Matthew Wilcox
2021-05-18 4:03 ` Anshuman Khandual
0 siblings, 1 reply; 4+ messages in thread
From: Matthew Wilcox @ 2021-05-13 21:27 UTC (permalink / raw)
To: Randy Dunlap
Cc: Stephen Rothwell, Linux Next Mailing List,
Linux Kernel Mailing List, Alexander Duyck, Andrew Morton,
Linux MM, Anshuman Khandual
On Thu, May 13, 2021 at 10:29:49AM -0700, Randy Dunlap wrote:
> On 5/12/21 10:44 PM, Stephen Rothwell wrote:
> > Hi all,
> >
> > Changes since 20210512:
> >
>
> on x86_64:
>
> In function ‘__mm_zero_struct_page.isra.75’,
> inlined from ‘__init_single_page.isra.76’ at ../mm/page_alloc.c:1494:2:
> ./../include/linux/compiler_types.h:328:38: error: call to ‘__compiletime_assert_162’ declared with attribute error: BUILD_BUG_ON failed: sizeof(struct page) > 80
Hmm.
struct {
long unsigned int _pt_pad_1; /* 8 8 */
pgtable_t pmd_huge_pte; /* 16 8 */
long unsigned int _pt_pad_2; /* 24 8 */
union {
struct mm_struct * pt_mm; /* 32 8 */
atomic_t pt_frag_refcount; /* 32 4 */
}; /* 32 8 */
spinlock_t ptl; /* 40 72 */
}; /* 8 104 */
#if ALLOC_SPLIT_PTLOCKS
spinlock_t *ptl;
#else
spinlock_t ptl;
#endif
something has disabled ALLOC_SPLIT_PTLOCKS when it ought to be enabled.
#if USE_SPLIT_PTE_PTLOCKS
#define ALLOC_SPLIT_PTLOCKS (SPINLOCK_SIZE > BITS_PER_LONG/8)
#else
#define ALLOC_SPLIT_PTLOCKS 0
#endif
Oh. This is Anshuman's fault.
commit 9b8a39056e2472592a5e5897987387f43038b8ba
Author: Anshuman Khandual <anshuman.khandual@arm.com>
Date: Tue May 11 15:06:01 2021 +1000
mm/thp: make ALLOC_SPLIT_PTLOCKS dependent on USE_SPLIT_PTE_PTLOCKS
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: linux-next: Tree for May 13 (mm/page_alloc.c, <linux/mm.h>: sizeof(struct page))
2021-05-13 21:27 ` Matthew Wilcox
@ 2021-05-18 4:03 ` Anshuman Khandual
2021-05-18 4:59 ` Randy Dunlap
0 siblings, 1 reply; 4+ messages in thread
From: Anshuman Khandual @ 2021-05-18 4:03 UTC (permalink / raw)
To: Matthew Wilcox, Randy Dunlap
Cc: Stephen Rothwell, Linux Next Mailing List,
Linux Kernel Mailing List, Alexander Duyck, Andrew Morton,
Linux MM
On 5/14/21 2:57 AM, Matthew Wilcox wrote:
> On Thu, May 13, 2021 at 10:29:49AM -0700, Randy Dunlap wrote:
>> On 5/12/21 10:44 PM, Stephen Rothwell wrote:
>>> Hi all,
>>>
>>> Changes since 20210512:
>>>
>>
>> on x86_64:
>>
>> In function ‘__mm_zero_struct_page.isra.75’,
>> inlined from ‘__init_single_page.isra.76’ at ../mm/page_alloc.c:1494:2:
>> ./../include/linux/compiler_types.h:328:38: error: call to ‘__compiletime_assert_162’ declared with attribute error: BUILD_BUG_ON failed: sizeof(struct page) > 80
>
> Hmm.
>
> struct {
> long unsigned int _pt_pad_1; /* 8 8 */
> pgtable_t pmd_huge_pte; /* 16 8 */
> long unsigned int _pt_pad_2; /* 24 8 */
> union {
> struct mm_struct * pt_mm; /* 32 8 */
> atomic_t pt_frag_refcount; /* 32 4 */
> }; /* 32 8 */
> spinlock_t ptl; /* 40 72 */
> }; /* 8 104 */
>
> #if ALLOC_SPLIT_PTLOCKS
> spinlock_t *ptl;
> #else
> spinlock_t ptl;
> #endif
>
> something has disabled ALLOC_SPLIT_PTLOCKS when it ought to be enabled.
>
> #if USE_SPLIT_PTE_PTLOCKS
> #define ALLOC_SPLIT_PTLOCKS (SPINLOCK_SIZE > BITS_PER_LONG/8)
> #else
> #define ALLOC_SPLIT_PTLOCKS 0
> #endif
>
> Oh. This is Anshuman's fault.
>
> commit 9b8a39056e2472592a5e5897987387f43038b8ba
> Author: Anshuman Khandual <anshuman.khandual@arm.com>
> Date: Tue May 11 15:06:01 2021 +1000
>
> mm/thp: make ALLOC_SPLIT_PTLOCKS dependent on USE_SPLIT_PTE_PTLOCKS
>
>
Previously ALLOC_SPLIT_PTLOCKS was evaluated and the spin lock element
in struct page was getting created independent of whether split pte
locks are being used or not. AFAICS without USE_SPLIT_PTE_PTLOCKS, it
does not really matter whether struct page has spinlock_t *ptl or ptl
element because that is not going to be used. Should the BUILD_BUG_ON()
evaluation be changed when USE_SPLIT_PTE_PTLOCKS is not enabled or we
could something like this which drops the ptl element in such cases ?
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -152,11 +152,13 @@ struct page {
struct mm_struct *pt_mm; /* x86 pgds only */
atomic_t pt_frag_refcount; /* powerpc */
};
+#if USE_SPLIT_PTE_PTLOCKS
#if ALLOC_SPLIT_PTLOCKS
spinlock_t *ptl;
#else
spinlock_t ptl;
#endif
+#endif
};
struct { /* ZONE_DEVICE pages */
/** @pgmap: Points to the hosting device page map. */
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: linux-next: Tree for May 13 (mm/page_alloc.c, <linux/mm.h>: sizeof(struct page))
2021-05-18 4:03 ` Anshuman Khandual
@ 2021-05-18 4:59 ` Randy Dunlap
0 siblings, 0 replies; 4+ messages in thread
From: Randy Dunlap @ 2021-05-18 4:59 UTC (permalink / raw)
To: Anshuman Khandual, Matthew Wilcox
Cc: Stephen Rothwell, Linux Next Mailing List,
Linux Kernel Mailing List, Alexander Duyck, Andrew Morton,
Linux MM
On 5/17/21 9:03 PM, Anshuman Khandual wrote:
>
>
> On 5/14/21 2:57 AM, Matthew Wilcox wrote:
>> On Thu, May 13, 2021 at 10:29:49AM -0700, Randy Dunlap wrote:
>>> On 5/12/21 10:44 PM, Stephen Rothwell wrote:
>>>> Hi all,
>>>>
>>>> Changes since 20210512:
>>>>
>>>
>>> on x86_64:
>>>
>>> In function ‘__mm_zero_struct_page.isra.75’,
>>> inlined from ‘__init_single_page.isra.76’ at ../mm/page_alloc.c:1494:2:
>>> ./../include/linux/compiler_types.h:328:38: error: call to ‘__compiletime_assert_162’ declared with attribute error: BUILD_BUG_ON failed: sizeof(struct page) > 80
>>
>> Hmm.
>>
>> struct {
>> long unsigned int _pt_pad_1; /* 8 8 */
>> pgtable_t pmd_huge_pte; /* 16 8 */
>> long unsigned int _pt_pad_2; /* 24 8 */
>> union {
>> struct mm_struct * pt_mm; /* 32 8 */
>> atomic_t pt_frag_refcount; /* 32 4 */
>> }; /* 32 8 */
>> spinlock_t ptl; /* 40 72 */
>> }; /* 8 104 */
>>
>> #if ALLOC_SPLIT_PTLOCKS
>> spinlock_t *ptl;
>> #else
>> spinlock_t ptl;
>> #endif
>>
>> something has disabled ALLOC_SPLIT_PTLOCKS when it ought to be enabled.
>>
>> #if USE_SPLIT_PTE_PTLOCKS
>> #define ALLOC_SPLIT_PTLOCKS (SPINLOCK_SIZE > BITS_PER_LONG/8)
>> #else
>> #define ALLOC_SPLIT_PTLOCKS 0
>> #endif
>>
>> Oh. This is Anshuman's fault.
>>
>> commit 9b8a39056e2472592a5e5897987387f43038b8ba
>> Author: Anshuman Khandual <anshuman.khandual@arm.com>
>> Date: Tue May 11 15:06:01 2021 +1000
>>
>> mm/thp: make ALLOC_SPLIT_PTLOCKS dependent on USE_SPLIT_PTE_PTLOCKS
>>
>>
>
> Previously ALLOC_SPLIT_PTLOCKS was evaluated and the spin lock element
> in struct page was getting created independent of whether split pte
> locks are being used or not. AFAICS without USE_SPLIT_PTE_PTLOCKS, it
> does not really matter whether struct page has spinlock_t *ptl or ptl
> element because that is not going to be used. Should the BUILD_BUG_ON()
> evaluation be changed when USE_SPLIT_PTE_PTLOCKS is not enabled or we
> could something like this which drops the ptl element in such cases ?
>
> --- a/include/linux/mm_types.h
> +++ b/include/linux/mm_types.h
> @@ -152,11 +152,13 @@ struct page {
> struct mm_struct *pt_mm; /* x86 pgds only */
> atomic_t pt_frag_refcount; /* powerpc */
> };
> +#if USE_SPLIT_PTE_PTLOCKS
> #if ALLOC_SPLIT_PTLOCKS
> spinlock_t *ptl;
> #else
> spinlock_t ptl;
> #endif
> +#endif
> };
> struct { /* ZONE_DEVICE pages */
> /** @pgmap: Points to the hosting device page map. */
>
OK, that works. Thanks.
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
I guess you should send a proper patch to Andrew. The code above
is whitespace-damaged (cut'n'paste).
--
~Randy
^ permalink raw reply [flat|nested] 4+ messages in thread
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[not found] <20210513154418.2946f422@canb.auug.org.au>
2021-05-13 17:29 ` linux-next: Tree for May 13 (mm/page_alloc.c, <linux/mm.h>: sizeof(struct page)) Randy Dunlap
2021-05-13 21:27 ` Matthew Wilcox
2021-05-18 4:03 ` Anshuman Khandual
2021-05-18 4:59 ` Randy Dunlap
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