From: Vijay Balakrishna <vijayb@linux.microsoft.com>
To: Andrew Morton <akpm@linux-foundation.org>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Oleg Nesterov <oleg@redhat.com>, Song Liu <songliubraving@fb.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Pavel Tatashin <pasha.tatashin@soleen.com>,
Michal Hocko <mhocko@suse.com>, Allen Pais <apais@microsoft.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [v3 2/2] mm: khugepaged: avoid overriding min_free_kbytes set by user
Date: Wed, 16 Sep 2020 21:22:06 -0700 [thread overview]
Message-ID: <a9b53080-9dc3-c1ee-8126-eaf8e38ce736@linux.microsoft.com> (raw)
In-Reply-To: <1600305709-2319-3-git-send-email-vijayb@linux.microsoft.com>
Please ignore this patch. I forgot to run scripts/checkpatch.pl and see
CHECK: Alignment should match open parenthesis
#30: FILE: mm/khugepaged.c:2287:
+ if (recommended_min > min_free_kbytes ||
+ recommended_min > user_min_free_kbytes) {
ERROR: do not initialise globals to 0
#43: FILE: mm/page_alloc.c:318:
+int user_min_free_kbytes = 0;
Sorry for trouble, I will send a new version.
Vijay
On 9/16/2020 6:21 PM, Vijay Balakrishna wrote:
> set_recommended_min_free_kbytes need to honor min_free_kbytes set by the
> user. Post start-of-day THP enable or memory hotplug operations can
> lose user specified min_free_kbytes, in particular when it is higher than
> calculated recommended value. user_min_free_kbytes initialized to 0
> to avoid undesired result when comparing with "unsigned long" type.
>
> Signed-off-by: Vijay Balakrishna <vijayb@linux.microsoft.com>
> Cc: stable@vger.kernel.org
> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
> ---
> mm/khugepaged.c | 3 ++-
> mm/page_alloc.c | 2 +-
> 2 files changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> index 4f7107476a6f..3c1147816d12 100644
> --- a/mm/khugepaged.c
> +++ b/mm/khugepaged.c
> @@ -2283,7 +2283,8 @@ static void set_recommended_min_free_kbytes(void)
> (unsigned long) nr_free_buffer_pages() / 20);
> recommended_min <<= (PAGE_SHIFT-10);
>
> - if (recommended_min > min_free_kbytes) {
> + if (recommended_min > min_free_kbytes ||
> + recommended_min > user_min_free_kbytes) {
> if (user_min_free_kbytes >= 0)
> pr_info("raising min_free_kbytes from %d to %lu to help transparent hugepage allocations\n",
> min_free_kbytes, recommended_min);
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index fab5e97dc9ca..7b81fb139034 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -315,7 +315,7 @@ compound_page_dtor * const compound_page_dtors[NR_COMPOUND_DTORS] = {
> };
>
> int min_free_kbytes = 1024;
> -int user_min_free_kbytes = -1;
> +int user_min_free_kbytes = 0;
> #ifdef CONFIG_DISCONTIGMEM
> /*
> * DiscontigMem defines memory ranges as separate pg_data_t even if the ranges
>
next prev parent reply other threads:[~2020-09-17 4:22 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-17 1:21 [v3 0/2] recalculate min_free_kbytes post memory hotplug Vijay Balakrishna
2020-09-17 1:21 ` [v3 1/2] mm: khugepaged: recalculate min_free_kbytes after memory hotplug as expected by khugepaged Vijay Balakrishna
2020-09-21 12:55 ` Sasha Levin
2020-09-23 21:27 ` Vijay Balakrishna
2020-09-25 2:51 ` Andrew Morton
2020-09-25 7:45 ` Michal Hocko
2020-09-25 7:42 ` Michal Hocko
2020-09-25 16:31 ` Vijay Balakrishna
2020-09-17 1:21 ` [v3 2/2] mm: khugepaged: avoid overriding min_free_kbytes set by user Vijay Balakrishna
2020-09-17 4:22 ` Vijay Balakrishna [this message]
2020-09-21 12:54 ` Sasha Levin
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