linux-kernel - RE: [External] Re: [PATCH 1/1] mm/vmalloc: Add preempt point in purge_vmap

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Message-ID: 
 <TYZPR03MB619290520C6552B540870C32B3DA2@TYZPR03MB6192.apcprd03.prod.outlook.com>
Date: Mon, 8 Jul 2024 13:39:57 +0000
From: Adrian Huang12 <ahuang12@...ovo.com>
To: Uladzislau Rezki <urezki@...il.com>,
        Adrian Huang
	<adrianhuang0701@...il.com>
CC: Andrew Morton <akpm@...ux-foundation.org>,
        Christoph Hellwig
	<hch@...radead.org>,
        "linux-mm@...ck.org" <linux-mm@...ck.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Jiwei JW10 Sun
	<sunjw10@...ovo.com>
Subject: RE: [External] Re: [PATCH 1/1] mm/vmalloc: Add preempt point in
 purge_vmap_node() when enabling kasan

Hi,

> Could you please test it:
> 
> <snip>
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 03b82fb8ecd3..6dc204b8495a
> 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -2190,10 +2190,12 @@ static void purge_vmap_node(struct work_struct
> *work)  {
>  	struct vmap_node *vn = container_of(work,
>  		struct vmap_node, purge_work);
> +	unsigned long resched_threshold;
>  	struct vmap_area *va, *n_va;
>  	LIST_HEAD(local_list);
> 
>  	vn->nr_purged = 0;
> +	resched_threshold = lazy_max_pages() << 1;
> 
>  	list_for_each_entry_safe(va, n_va, &vn->purge_list, list) {
>  		unsigned long nr = (va->va_end - va->va_start) >> PAGE_SHIFT; @@
> -2210,6 +2212,9 @@ static void purge_vmap_node(struct work_struct *work)
>  		atomic_long_sub(nr, &vmap_lazy_nr);
>  		vn->nr_purged++;
> 
> +		if (atomic_long_read(&vmap_lazy_nr) < resched_threshold)
> +			cond_resched();
> +
>  		if (is_vn_id_valid(vn_id) && !vn->skip_populate)
>  			if (node_pool_add_va(vn, va))
>  				continue;
> <snip>

This patch can fix the issue. Feel free to add my tested-by.
Tested-by: Adrian Huang <ahuang12@...ovo.com>

-- Adrian