* + kasan-avoid-sleepable-page-allocation-from-atomic-context-v7.patch added to mm-hotfixes-unstable branch
@ 2025-05-12 22:23 Andrew Morton
2025-05-12 23:50 ` Harry Yoo
0 siblings, 1 reply; 3+ messages in thread
From: Andrew Morton @ 2025-05-12 22:23 UTC (permalink / raw)
To: mm-commits, ryabinin.a.a, harry.yoo, dja, agordeev, akpm
The patch titled
Subject: kasan-avoid-sleepable-page-allocation-from-atomic-context-v7
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
kasan-avoid-sleepable-page-allocation-from-atomic-context-v7.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/kasan-avoid-sleepable-page-allocation-from-atomic-context-v7.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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 via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Alexander Gordeev <agordeev@linux.ibm.com>
Subject: kasan-avoid-sleepable-page-allocation-from-atomic-context-v7
Date: Mon, 12 May 2025 16:27:06 +0200
do not unnecessary free pages across iterations
Link: https://lkml.kernel.org/r/c8eeeb146382bcadabce5b5dcf92e6176ba4fb04.1747059374.git.agordeev@linux.ibm.com
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Suggested-by: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Cc: Daniel Axtens <dja@axtens.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/kasan/shadow.c | 15 +++++++--------
1 file changed, 7 insertions(+), 8 deletions(-)
--- a/mm/kasan/shadow.c~kasan-avoid-sleepable-page-allocation-from-atomic-context-v7
+++ a/mm/kasan/shadow.c
@@ -337,9 +337,9 @@ static inline void free_pages_bulk(struc
static int __kasan_populate_vmalloc(unsigned long start, unsigned long end)
{
- unsigned long nr_populated, nr_pages, nr_total = PFN_UP(end - start);
+ unsigned long nr_pages, nr_populated = 0, nr_total = PFN_UP(end - start);
struct vmalloc_populate_data data;
- int ret;
+ int ret = 0;
data.pages = (struct page **)__get_free_page(GFP_KERNEL | __GFP_ZERO);
if (!data.pages)
@@ -349,25 +349,24 @@ static int __kasan_populate_vmalloc(unsi
nr_pages = min(nr_total, PAGE_SIZE / sizeof(data.pages[0]));
nr_populated = alloc_pages_bulk(GFP_KERNEL, nr_pages, data.pages);
if (nr_populated != nr_pages) {
- free_pages_bulk(data.pages, nr_populated);
- free_page((unsigned long)data.pages);
- return -ENOMEM;
+ ret = -ENOMEM;
+ break;
}
data.start = start;
ret = apply_to_page_range(&init_mm, start, nr_pages * PAGE_SIZE,
kasan_populate_vmalloc_pte, &data);
- free_pages_bulk(data.pages, nr_pages);
if (ret)
- return ret;
+ break;
start += nr_pages * PAGE_SIZE;
nr_total -= nr_pages;
}
+ free_pages_bulk(data.pages, nr_populated);
free_page((unsigned long)data.pages);
- return 0;
+ return ret;
}
int kasan_populate_vmalloc(unsigned long addr, unsigned long size)
_
Patches currently in -mm which might be from agordeev@linux.ibm.com are
kasan-avoid-sleepable-page-allocation-from-atomic-context.patch
kasan-avoid-sleepable-page-allocation-from-atomic-context-v7.patch
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: + kasan-avoid-sleepable-page-allocation-from-atomic-context-v7.patch added to mm-hotfixes-unstable branch
2025-05-12 22:23 + kasan-avoid-sleepable-page-allocation-from-atomic-context-v7.patch added to mm-hotfixes-unstable branch Andrew Morton
@ 2025-05-12 23:50 ` Harry Yoo
2025-05-13 1:14 ` Andrew Morton
0 siblings, 1 reply; 3+ messages in thread
From: Harry Yoo @ 2025-05-12 23:50 UTC (permalink / raw)
To: Andrew Morton; +Cc: mm-commits, ryabinin.a.a, dja, agordeev
On Mon, May 12, 2025 at 03:23:07PM -0700, Andrew Morton wrote:
>
> The patch titled
> Subject: kasan-avoid-sleepable-page-allocation-from-atomic-context-v7
> has been added to the -mm mm-hotfixes-unstable branch. Its filename is
> kasan-avoid-sleepable-page-allocation-from-atomic-context-v7.patch
>
> This patch will shortly appear at
> https://urldefense.com/v3/__https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/kasan-avoid-sleepable-page-allocation-from-atomic-context-v7.patch__;!!ACWV5N9M2RV99hQ!IDZGs5LvdWUbyEOsjCGQ9n4Rk5nHMYzHfbAvvr0U07eEBuITVQjUmFA0nvwv6w4E_2SDwb99rlhHW1qS4ZW84Q$
>
> This patch will later appear in the mm-hotfixes-unstable branch at
> git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
>
> 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 via the mm-everything
> branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
> and is updated there every 2-3 working days
>
> ------------------------------------------------------
> From: Alexander Gordeev <agordeev@linux.ibm.com>
> Subject: kasan-avoid-sleepable-page-allocation-from-atomic-context-v7
> Date: Mon, 12 May 2025 16:27:06 +0200
>
> do not unnecessary free pages across iterations
>
> Link: https://urldefense.com/v3/__https://lkml.kernel.org/r/c8eeeb146382bcadabce5b5dcf92e6176ba4fb04.1747059374.git.agordeev@linux.ibm.com__;!!ACWV5N9M2RV99hQ!IDZGs5LvdWUbyEOsjCGQ9n4Rk5nHMYzHfbAvvr0U07eEBuITVQjUmFA0nvwv6w4E_2SDwb99rlhHW1oEPUM6Aw$
> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
> Suggested-by: Andrey Ryabinin <ryabinin.a.a@gmail.com>
> Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
> Cc: Daniel Axtens <dja@axtens.net>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> ---
Andrew, please drop this patch
(kasan-avoid-sleepable-page-allocation-from-atomic-context-v7.patch).
v7 has a memory leak and after discussing with Alexander this
'optimization' doesn't seem worth here.
But as Alexander mentioned v6 also has a memory leak in an error case,
and I believe a proper fix to that should be (lightly tested on my box)
below.
And with the change below on top of v6, it looks good to me.
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c
index 660cc2148575..8212a7007b02 100644
--- a/mm/kasan/shadow.c
+++ b/mm/kasan/shadow.c
@@ -339,7 +339,7 @@ static int __kasan_populate_vmalloc(unsigned long start, unsigned long end)
{
unsigned long nr_populated, nr_pages, nr_total = PFN_UP(end - start);
struct vmalloc_populate_data data;
- int ret;
+ int ret = 0;
data.pages = (struct page **)__get_free_page(GFP_KERNEL | __GFP_ZERO);
if (!data.pages)
@@ -350,8 +350,8 @@ static int __kasan_populate_vmalloc(unsigned long start, unsigned long end)
nr_populated = alloc_pages_bulk(GFP_KERNEL, nr_pages, data.pages);
if (nr_populated != nr_pages) {
free_pages_bulk(data.pages, nr_populated);
- free_page((unsigned long)data.pages);
- return -ENOMEM;
+ ret = -ENOMEM;
+ break;
}
data.start = start;
@@ -359,7 +359,7 @@ static int __kasan_populate_vmalloc(unsigned long start, unsigned long end)
kasan_populate_vmalloc_pte, &data);
free_pages_bulk(data.pages, nr_pages);
if (ret)
- return ret;
+ break;
start += nr_pages * PAGE_SIZE;
nr_total -= nr_pages;
@@ -367,7 +367,7 @@ static int __kasan_populate_vmalloc(unsigned long start, unsigned long end)
free_page((unsigned long)data.pages);
- return 0;
+ return ret;
}
int kasan_populate_vmalloc(unsigned long addr, unsigned long size)
--
Cheers,
Harry / Hyeonggon
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: + kasan-avoid-sleepable-page-allocation-from-atomic-context-v7.patch added to mm-hotfixes-unstable branch
2025-05-12 23:50 ` Harry Yoo
@ 2025-05-13 1:14 ` Andrew Morton
0 siblings, 0 replies; 3+ messages in thread
From: Andrew Morton @ 2025-05-13 1:14 UTC (permalink / raw)
To: Harry Yoo; +Cc: mm-commits, ryabinin.a.a, dja, agordeev
On Tue, 13 May 2025 08:50:56 +0900 Harry Yoo <harry.yoo@oracle.com> wrote:
> Andrew, please drop this patch
> (kasan-avoid-sleepable-page-allocation-from-atomic-context-v7.patch).
>
> v7 has a memory leak and after discussing with Alexander this
> 'optimization' doesn't seem worth here.
>
> But as Alexander mentioned v6 also has a memory leak in an error case,
> and I believe a proper fix to that should be (lightly tested on my box)
> below.
>
> And with the change below on top of v6, it looks good to me.
But does it run good ;)
I'll drop everything and shall await v8, please.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2025-05-12 22:23 + kasan-avoid-sleepable-page-allocation-from-atomic-context-v7.patch added to mm-hotfixes-unstable branch Andrew Morton
2025-05-12 23:50 ` Harry Yoo
2025-05-13 1:14 ` Andrew Morton
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