* Re: + mm-gup-track-foll_pin-pages-fix-2.patch added to -mm tree
[not found] <20200307232517.0eSNFUWfN%akpm@linux-foundation.org>
@ 2020-03-11 1:46 ` John Hubbard
2020-03-11 10:13 ` Claudio Imbrenda
0 siblings, 1 reply; 4+ messages in thread
From: John Hubbard @ 2020-03-11 1:46 UTC (permalink / raw)
To: Andrew Morton, imbrenda, mm-commits, Linux-MM
On 3/7/20 3:25 PM, Andrew Morton wrote:
>
> The patch titled
> Subject: mm/gup: fixup for 9947ea2c1e608e32 "mm/gup: track FOLL_PIN pages"
> has been added to the -mm tree. Its filename is
> mm-gup-track-foll_pin-pages-fix-2.patch
>
This appears to be causing a build failure in mm/gup.c, in mmotm, as of today anyway:
commit 5d9ee416b570 ("pci: test for unexpectedly disabled bridges")
I vaguely recall reviewing an earlier version that moved put_compound_head() up higher in
gup.c, in order to avoid this. In any case, that's what this needs in order to build.
Sorry for missing it in the review.
Claudio, did you compile-test the patch? I'm not sure how this made it all the way to mmotm
without it triggering something, either, but I can't see anything obviously wrong with my
tree, which has no local changes applied.
Here's what I'm seeing, and it makes sense because put_compound_head() is actually at
line 2323:
mm/gup.c: In function ‘gup_pte_range’:
mm/gup.c:2177:4: error: implicit declaration of function ‘put_compound_head’; did you mean ‘set_compound_head’? [-Werror=implicit-function-declaration]
2177 | put_compound_head(head, 1, flags);
| ^~~~~~~~~~~~~~~~~
| set_compound_head
mm/gup.c: At top level:
mm/gup.c:2323:13: warning: conflicting types for ‘put_compound_head’
2323 | static void put_compound_head(struct page *page, int refs, unsigned int flags)
| ^~~~~~~~~~~~~~~~~
mm/gup.c:2323:13: error: static declaration of ‘put_compound_head’ follows non-static declaration
mm/gup.c:2177:4: note: previous implicit declaration of ‘put_compound_head’ was here
2177 | put_compound_head(head, 1, flags);
| ^~~~~~~~~~~~~~~~~
And here's a compile-tested (only) proposed fix:
diff --git a/mm/gup.c b/mm/gup.c
index 722fcdd32ab8..6344252f0632 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -2116,6 +2116,28 @@ static inline pte_t gup_get_pte(pte_t *ptep)
}
#endif /* CONFIG_GUP_GET_PTE_LOW_HIGH */
+static void put_compound_head(struct page *page, int refs, unsigned int flags)
+{
+ if (flags & FOLL_PIN) {
+ mod_node_page_state(page_pgdat(page), NR_FOLL_PIN_RELEASED,
+ refs);
+
+ if (hpage_pincount_available(page))
+ hpage_pincount_sub(page, refs);
+ else
+ refs *= GUP_PIN_COUNTING_BIAS;
+ }
+
+ VM_BUG_ON_PAGE(page_ref_count(page) < refs, page);
+ /*
+ * Calling put_page() for each ref is unnecessarily slow. Only the last
+ * ref needs a put_page().
+ */
+ if (refs > 1)
+ page_ref_sub(page, refs - 1);
+ put_page(page);
+}
+
static void __maybe_unused undo_dev_pagemap(int *nr, int nr_start,
unsigned int flags,
struct page **pages)
@@ -2320,28 +2342,6 @@ static int record_subpages(struct page *page, unsigned long addr,
return nr;
}
-static void put_compound_head(struct page *page, int refs, unsigned int flags)
-{
- if (flags & FOLL_PIN) {
- mod_node_page_state(page_pgdat(page), NR_FOLL_PIN_RELEASED,
- refs);
-
- if (hpage_pincount_available(page))
- hpage_pincount_sub(page, refs);
- else
- refs *= GUP_PIN_COUNTING_BIAS;
- }
-
- VM_BUG_ON_PAGE(page_ref_count(page) < refs, page);
- /*
- * Calling put_page() for each ref is unnecessarily slow. Only the last
- * ref needs a put_page().
- */
- if (refs > 1)
- page_ref_sub(page, refs - 1);
- put_page(page);
-}
-
#ifdef CONFIG_ARCH_HAS_HUGEPD
static unsigned long hugepte_addr_end(unsigned long addr, unsigned long end,
unsigned long sz)
thanks,
--
John Hubbard
NVIDIA
> This patch should soon appear at
> http://ozlabs.org/~akpm/mmots/broken-out/mm-gup-track-foll_pin-pages-fix-2.patch
> and later at
> http://ozlabs.org/~akpm/mmotm/broken-out/mm-gup-track-foll_pin-pages-fix-2.patch
>
> Before you just go and hit "reply", please:
> a) Consider who else should be cc'ed
> b) Prefer to cc a suitable mailing list as well
> c) Ideally: find the original patch on the mailing list and do a
> reply-to-all to that, adding suitable additional cc's
>
> *** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
>
> The -mm tree is included into linux-next and is updated
> there every 3-4 working days
>
> ------------------------------------------------------
> From: Claudio Imbrenda <imbrenda@linux.ibm.com>
> Subject: mm/gup: fixup for 9947ea2c1e608e32 "mm/gup: track FOLL_PIN pages"
>
> In case pin fails, we need to unpin, a simple put_page will not be enough
>
> fixup for commit 9947ea2c1e608e32 ("mm/gup: track FOLL_PIN pages")
>
> it can be simply squashed in
>
> Link: http://lkml.kernel.org/r/20200306132537.783769-2-imbrenda@linux.ibm.com
> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
> Reviewed-by: John Hubbard <jhubbard@nvidia.com>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> ---
>
> mm/gup.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> --- a/mm/gup.c~mm-gup-track-foll_pin-pages-fix-2
> +++ a/mm/gup.c
> @@ -2065,7 +2065,7 @@ static int gup_pte_range(pmd_t pmd, unsi
> goto pte_unmap;
>
> if (unlikely(pte_val(pte) != pte_val(*ptep))) {
> - put_page(head);
> + put_compound_head(head, 1, flags);
> goto pte_unmap;
> }
>
> _
>
> Patches currently in -mm which might be from imbrenda@linux.ibm.com are
>
> mm-gup-track-foll_pin-pages-fix-2.patch
> mm-gup-writeback-add-callbacks-for-inaccessible-pages.patch
>
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: + mm-gup-track-foll_pin-pages-fix-2.patch added to -mm tree
2020-03-11 1:46 ` + mm-gup-track-foll_pin-pages-fix-2.patch added to -mm tree John Hubbard
@ 2020-03-11 10:13 ` Claudio Imbrenda
2020-03-12 0:14 ` John Hubbard
2020-03-12 0:51 ` Andrew Morton
0 siblings, 2 replies; 4+ messages in thread
From: Claudio Imbrenda @ 2020-03-11 10:13 UTC (permalink / raw)
To: John Hubbard; +Cc: Andrew Morton, mm-commits, Linux-MM
On Tue, 10 Mar 2020 18:46:40 -0700
John Hubbard <jhubbard@nvidia.com> wrote:
> On 3/7/20 3:25 PM, Andrew Morton wrote:
> >
> > The patch titled
> > Subject: mm/gup: fixup for 9947ea2c1e608e32 "mm/gup: track
> > FOLL_PIN pages" has been added to the -mm tree. Its filename is
> > mm-gup-track-foll_pin-pages-fix-2.patch
> >
>
> This appears to be causing a build failure in mm/gup.c, in mmotm, as
> of today anyway:
>
> commit 5d9ee416b570 ("pci: test for unexpectedly disabled
> bridges")
>
>
> I vaguely recall reviewing an earlier version that moved
> put_compound_head() up higher in gup.c, in order to avoid this. In
yes, that is what I had sent
> any case, that's what this needs in order to build. Sorry for missing
> it in the review.
I don't think you missed it, because the patch I sent out to be
squashed did move it up
> Claudio, did you compile-test the patch? I'm not sure how this made
not only compile tested, I even actually tested-tested it.
> it all the way to mmotm without it triggering something, either, but
> I can't see anything obviously wrong with my tree, which has no local
> changes applied.
>
> Here's what I'm seeing, and it makes sense because
> put_compound_head() is actually at line 2323:
the patch I had sent out did move put_compound_head to around line 116
> mm/gup.c: In function ‘gup_pte_range’:
> mm/gup.c:2177:4: error: implicit declaration of function
> ‘put_compound_head’; did you mean ‘set_compound_head’?
> [-Werror=implicit-function-declaration] 2177 |
> put_compound_head(head, 1, flags); | ^~~~~~~~~~~~~~~~~ |
> set_compound_head mm/gup.c: At top level:
> mm/gup.c:2323:13: warning: conflicting types for ‘put_compound_head’
> 2323 | static void put_compound_head(struct page *page, int refs,
> unsigned int flags) | ^~~~~~~~~~~~~~~~~
> mm/gup.c:2323:13: error: static declaration of ‘put_compound_head’
> follows non-static declaration mm/gup.c:2177:4: note: previous
> implicit declaration of ‘put_compound_head’ was here 2177 |
> put_compound_head(head, 1, flags); | ^~~~~~~~~~~~~~~~~
>
> And here's a compile-tested (only) proposed fix:
I think the most appropriate place would be right after
try_grab_compound_head, which is where I had put it.
> diff --git a/mm/gup.c b/mm/gup.c
> index 722fcdd32ab8..6344252f0632 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -2116,6 +2116,28 @@ static inline pte_t gup_get_pte(pte_t *ptep)
> }
> #endif /* CONFIG_GUP_GET_PTE_LOW_HIGH */
>
> +static void put_compound_head(struct page *page, int refs, unsigned
> int flags) +{
> + if (flags & FOLL_PIN) {
> + mod_node_page_state(page_pgdat(page),
> NR_FOLL_PIN_RELEASED,
> + refs);
> +
> + if (hpage_pincount_available(page))
> + hpage_pincount_sub(page, refs);
> + else
> + refs *= GUP_PIN_COUNTING_BIAS;
> + }
> +
> + VM_BUG_ON_PAGE(page_ref_count(page) < refs, page);
> + /*
> + * Calling put_page() for each ref is unnecessarily slow.
> Only the last
> + * ref needs a put_page().
> + */
> + if (refs > 1)
> + page_ref_sub(page, refs - 1);
> + put_page(page);
> +}
> +
> static void __maybe_unused undo_dev_pagemap(int *nr, int nr_start,
> unsigned int flags,
> struct page **pages)
> @@ -2320,28 +2342,6 @@ static int record_subpages(struct page *page,
> unsigned long addr, return nr;
> }
>
> -static void put_compound_head(struct page *page, int refs, unsigned
> int flags) -{
> - if (flags & FOLL_PIN) {
> - mod_node_page_state(page_pgdat(page),
> NR_FOLL_PIN_RELEASED,
> - refs);
> -
> - if (hpage_pincount_available(page))
> - hpage_pincount_sub(page, refs);
> - else
> - refs *= GUP_PIN_COUNTING_BIAS;
> - }
> -
> - VM_BUG_ON_PAGE(page_ref_count(page) < refs, page);
> - /*
> - * Calling put_page() for each ref is unnecessarily slow.
> Only the last
> - * ref needs a put_page().
> - */
> - if (refs > 1)
> - page_ref_sub(page, refs - 1);
> - put_page(page);
> -}
> -
> #ifdef CONFIG_ARCH_HAS_HUGEPD
> static unsigned long hugepte_addr_end(unsigned long addr, unsigned
> long end, unsigned long sz)
>
>
>
> thanks,
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: + mm-gup-track-foll_pin-pages-fix-2.patch added to -mm tree
2020-03-11 10:13 ` Claudio Imbrenda
@ 2020-03-12 0:14 ` John Hubbard
2020-03-12 0:51 ` Andrew Morton
1 sibling, 0 replies; 4+ messages in thread
From: John Hubbard @ 2020-03-12 0:14 UTC (permalink / raw)
To: Claudio Imbrenda; +Cc: Andrew Morton, mm-commits, Linux-MM
On 3/11/20 3:13 AM, Claudio Imbrenda wrote:
> On Tue, 10 Mar 2020 18:46:40 -0700
> John Hubbard <jhubbard@nvidia.com> wrote:
>
>> On 3/7/20 3:25 PM, Andrew Morton wrote:
>>>
>>> The patch titled
>>> Subject: mm/gup: fixup for 9947ea2c1e608e32 "mm/gup: track
>>> FOLL_PIN pages" has been added to the -mm tree. Its filename is
>>> mm-gup-track-foll_pin-pages-fix-2.patch
>>>
>>
>> This appears to be causing a build failure in mm/gup.c, in mmotm, as
>> of today anyway:
>>
>> commit 5d9ee416b570 ("pci: test for unexpectedly disabled
>> bridges")
>>
>>
>> I vaguely recall reviewing an earlier version that moved
>> put_compound_head() up higher in gup.c, in order to avoid this. In
>
> yes, that is what I had sent
>
>> any case, that's what this needs in order to build. Sorry for missing
>> it in the review.
>
> I don't think you missed it, because the patch I sent out to be
> squashed did move it up
>
>> Claudio, did you compile-test the patch? I'm not sure how this made
>
> not only compile tested, I even actually tested-tested it.
Andrew, do you want Claudio to resend that patch? It seems like part of it
got lost, somehow.
thanks,
--
John Hubbard
NVIDIA
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: + mm-gup-track-foll_pin-pages-fix-2.patch added to -mm tree
2020-03-11 10:13 ` Claudio Imbrenda
2020-03-12 0:14 ` John Hubbard
@ 2020-03-12 0:51 ` Andrew Morton
1 sibling, 0 replies; 4+ messages in thread
From: Andrew Morton @ 2020-03-12 0:51 UTC (permalink / raw)
To: Claudio Imbrenda; +Cc: John Hubbard, mm-commits, Linux-MM
On Wed, 11 Mar 2020 11:13:52 +0100 Claudio Imbrenda <imbrenda@linux.ibm.com> wrote:
> > any case, that's what this needs in order to build. Sorry for missing
> > it in the review.
>
> I don't think you missed it, because the patch I sent out to be
> squashed did move it up
<figures out what happened>
hm, OK,
http://lkml.kernel.org/r/20200306132537.783769-2-imbrenda@linux.ibm.com
is billed as a fixup for 9947ea2c1e608e32 "mm/gup: track FOLL_PIN
pages" but it actually applies after everything else. I messed up
untangling this.
Redone, should be OK now.
^ permalink raw reply [flat|nested] 4+ messages in thread
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2020-03-11 1:46 ` + mm-gup-track-foll_pin-pages-fix-2.patch added to -mm tree John Hubbard
2020-03-11 10:13 ` Claudio Imbrenda
2020-03-12 0:14 ` John Hubbard
2020-03-12 0:51 ` Andrew Morton
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