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Date:   Wed, 31 Aug 2022 15:37:32 +0800
From:   Baoquan He <bhe@redhat.com>
To:     Song Liu <song@kernel.org>
Cc:     linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        songliubraving@fb.com, Uladzislau Rezki <urezki@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH] mm/vmalloc: Extend find_vmap_lowest_match_check with
 extra arguments
Message-ID: <Yw8PvP/SjDCE6DDX@MiWiFi-R3L-srv>
References: <20220831052734.3423079-1-song@kernel.org>
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In-Reply-To: <20220831052734.3423079-1-song@kernel.org>
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On 08/30/22 at 10:27pm, Song Liu wrote:
> find_vmap_lowest_match() is now able to handle different roots. Make
> similar changes to find_vmap_lowest_match_check() and
> find_vmap_lowest_linear_match() to handle different trees.

Good catch. Guess usually nobody eables DEBUG_AUGMENT_LOWEST_MATCH_CHECK
to trigger compilation of the code.

Reviewed-by: Baoquan He <bhe@redhat.com>

> 
> Fixes: f9863be49312 ("mm/vmalloc: extend __alloc_vmap_area() with extra arguments")
> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
> Cc: Baoquan He <bhe@redhat.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Signed-off-by: Song Liu <song@kernel.org>
> ---
>  mm/vmalloc.c | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index dd6cdb201195..088b421601c4 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -1300,12 +1300,12 @@ find_vmap_lowest_match(struct rb_root *root, unsigned long size,
>  #include <linux/random.h>
>  
>  static struct vmap_area *
> -find_vmap_lowest_linear_match(unsigned long size,
> +find_vmap_lowest_linear_match(struct list_head *head, unsigned long size,
>  	unsigned long align, unsigned long vstart)
>  {
>  	struct vmap_area *va;
>  
> -	list_for_each_entry(va, &free_vmap_area_list, list) {
> +	list_for_each_entry(va, head, list) {
>  		if (!is_within_this_va(va, size, align, vstart))
>  			continue;
>  
> @@ -1316,7 +1316,8 @@ find_vmap_lowest_linear_match(unsigned long size,
>  }
>  
>  static void
> -find_vmap_lowest_match_check(unsigned long size, unsigned long align)
> +find_vmap_lowest_match_check(struct rb_root *root, struct list_head *head,
> +			     unsigned long size, unsigned long align)
>  {
>  	struct vmap_area *va_1, *va_2;
>  	unsigned long vstart;
> @@ -1325,8 +1326,8 @@ find_vmap_lowest_match_check(unsigned long size, unsigned long align)
>  	get_random_bytes(&rnd, sizeof(rnd));
>  	vstart = VMALLOC_START + rnd;
>  
> -	va_1 = find_vmap_lowest_match(size, align, vstart, false);
> -	va_2 = find_vmap_lowest_linear_match(size, align, vstart);
> +	va_1 = find_vmap_lowest_match(root, size, align, vstart, false);
> +	va_2 = find_vmap_lowest_linear_match(head, size, align, vstart);
>  
>  	if (va_1 != va_2)
>  		pr_emerg("not lowest: t: 0x%p, l: 0x%p, v: 0x%lx\n",
> @@ -1513,7 +1514,7 @@ __alloc_vmap_area(struct rb_root *root, struct list_head *head,
>  		return vend;
>  
>  #if DEBUG_AUGMENT_LOWEST_MATCH_CHECK
> -	find_vmap_lowest_match_check(size, align);
> +	find_vmap_lowest_match_check(root, head, size, align);
>  #endif
>  
>  	return nva_start_addr;
> -- 
> 2.30.2
>