linux-kernel - Re: [PATCH v2 03/11] mm/damon/paddr: support addr_unit for DAMOS

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <7de69c95-bbf7-4dd0-91e9-640da8b8cd5c@huawei.com>
Date: Tue, 26 Aug 2025 11:16:56 +0800
From: Quanmin Yan <yanquanmin1@...wei.com>
To: SeongJae Park <sj@...nel.org>
CC: <akpm@...ux-foundation.org>, <damon@...ts.linux.dev>,
	<linux-kernel@...r.kernel.org>, <linux-mm@...ck.org>,
	<wangkefeng.wang@...wei.com>, <zuoze1@...wei.com>, <kernel-team@...a.com>,
	kernel test robot <lkp@...el.com>
Subject: Re: [PATCH v2 03/11] mm/damon/paddr: support addr_unit for
 DAMOS_PAGEOUT


在 2025/8/25 23:12, SeongJae Park 写道:
> On Fri, 22 Aug 2025 17:34:11 +0800 Quanmin Yan <yanquanmin1@...wei.com> wrote:
>
>> From: SeongJae Park <sj@...nel.org>
>>
>> Add support of addr_unit for DAMOS_PAGEOUT action handling from the
>> DAMOS operation implementation for the physical address space.
> [...]
>> -	return applied * PAGE_SIZE;
>> +	return applied * PAGE_SIZE / addr_unit;
>>   }
> Kernel test robot [1] found this can cause __udivdi3 linking issue.  Andrew,
> could you please add the below attached fixup?
>
> [1] https://lore.kernel.org/oe-kbuild-all/202508241831.EKwdwXZL-lkp@intel.com/
>
>
> Thanks,
> SJ
>
> [...]
>
> ==== Attachment 0 (0001-mm-damon-paddr-use-do_div-on-i386-for-damon_pa_pageo.patch) ====
>  From hackermail Thu Jan  1 00:00:00 1970
> From: SeongJae Park <sj@...nel.org>
> To: Andrew Morton <akpm@...ux-foundation.org>
> Cc: SeongJae Park <sj@...nel.org>
> Cc: damon@...ts.linux.dev
> Cc: kernel-team@...a.com
> Cc: linux-kernel@...r.kernel.org
> Cc: linux-mm@...ck.org
> Date: Mon, 25 Aug 2025 07:41:33 -0700
> Subject: [PATCH 1/3] mm/damon/paddr: use do_div() on i386 for damon_pa_pageout()
>           return value
>
> Otherwise, __udidi3 linking problem happens on certain configs.
>
> Reported-by: kernel test robot <lkp@...el.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202508241831.EKwdwXZL-lkp@intel.com/
> Signed-off-by: SeongJae Park <sj@...nel.org>
> ---
>   mm/damon/paddr.c | 14 +++++++++++++-
>   1 file changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/mm/damon/paddr.c b/mm/damon/paddr.c
> index 5fad2f9a99a0..09c87583af6c 100644
> --- a/mm/damon/paddr.c
> +++ b/mm/damon/paddr.c
> @@ -135,6 +135,18 @@ static bool damon_pa_invalid_damos_folio(struct folio *folio, struct damos *s)
>   	return false;
>   }
>   
> +/* convert physical address to core-layer address */
> +static unsigned long damon_pa_core_addr(phys_addr_t pa,
> +		unsigned long addr_unit)
> +{
> +#ifdef __i386__

Can we use the following condition instead?

#if !defined(CONFIG_64BIT) && defined(CONFIG_PHYS_ADDR_T_64BIT)

Thanks,
Quanmin Yan

> +	do_div(pa, addr_unit);
> +	return pa;
> +#else
> +	return pa / addr_unit;
> +#endif
> +}
> +
>   static unsigned long damon_pa_pageout(struct damon_region *r,
>   		unsigned long addr_unit, struct damos *s,
>   		unsigned long *sz_filter_passed)
> @@ -190,7 +202,7 @@ static unsigned long damon_pa_pageout(struct damon_region *r,
>   	applied = reclaim_pages(&folio_list);
>   	cond_resched();
>   	s->last_applied = folio;
> -	return applied * PAGE_SIZE / addr_unit;
> +	return damon_pa_core_addr(applied * PAGE_SIZE, addr_unit);
>   }
>   
>   static inline unsigned long damon_pa_mark_accessed_or_deactivate(