From: Wei Yang <richard.weiyang@gmail.com>
To: "Huang, Ying" <ying.huang@intel.com>
Cc: Wei Yang <richard.weiyang@gmail.com>,
akpm@linux-foundation.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, tim.c.chen@linux.intel.com
Subject: Re: [PATCH 4/4] mm/swapfile.c: move new_cluster to check free_clusters directly
Date: Mon, 20 Apr 2020 21:45:17 +0000 [thread overview]
Message-ID: <20200420214517.vnyc7mzxpyjhqr7b@master> (raw)
In-Reply-To: <87blnnszl4.fsf@yhuang-dev.intel.com>
On Mon, Apr 20, 2020 at 09:41:43AM +0800, Huang, Ying wrote:
>Wei Yang <richard.weiyang@gmail.com> writes:
>
>> Each time it needs jump to new_cluster, it is sure current
>> percpu_cluster is null.
>>
>> Move the new_cluster to check free_clusters directly.
>>
>> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
>> ---
>> mm/swapfile.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/mm/swapfile.c b/mm/swapfile.c
>> index 07b0bc095411..78e92ff14c79 100644
>> --- a/mm/swapfile.c
>> +++ b/mm/swapfile.c
>> @@ -603,9 +603,9 @@ static bool scan_swap_map_try_ssd_cluster(struct swap_info_struct *si,
>> struct swap_cluster_info *ci;
>> unsigned long tmp, max;
>>
>> -new_cluster:
>> cluster = this_cpu_ptr(si->percpu_cluster);
>> if (cluster_is_null(&cluster->index)) {
>> +new_cluster:
>> if (!cluster_list_empty(&si->free_clusters)) {
>> cluster->index = si->free_clusters.head;
>> cluster->next = cluster_next(&cluster->index) *
>
>In swap_do_scheduled_discard(), we will unlock si->lock, so the
>percpu_cluster may be changed after we releasing the lock. Or the
>current thread may be moved to a different CPU.
Thanks, you are right.
>
>Best Regards,
>Huang, Ying
--
Wei Yang
Help you, Help me
next prev parent reply other threads:[~2020-04-20 21:45 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-19 1:39 [PATCH 1/4] mm/swapfile.c: found_free could be represented by (tmp < max) Wei Yang
2020-04-19 1:39 ` [PATCH 2/4] mm/swapfile.c: tmp is always smaller than max Wei Yang
2020-04-19 1:39 ` [PATCH 4/4] mm/swapfile.c: move new_cluster to check free_clusters directly Wei Yang
2020-04-20 1:41 ` Huang, Ying
2020-04-20 21:45 ` Wei Yang [this message]
[not found] ` <20200419013921.14390-3-richard.weiyang@gmail.com>
2020-04-20 1:03 ` [PATCH 3/4] mm/swapfile.c: compare tmp and max after trying to iterate on swap_map Huang, Ying
2020-04-20 21:37 ` Wei Yang
2020-04-20 23:51 ` Huang, Ying
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