From: "Huang\, Ying" <ying.huang@intel.com>
To: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>, <linux-mm@kvack.org>,
<linux-kernel@vger.kernel.org>, Michal Hocko <mhocko@suse.com>,
"Johannes Weiner" <hannes@cmpxchg.org>,
Shaohua Li <shli@kernel.org>, Hugh Dickins <hughd@google.com>,
Minchan Kim <minchan@kernel.org>, Rik van Riel <riel@redhat.com>,
Dan Williams <dan.j.williams@intel.com>,
Dave Hansen <dave.hansen@linux.intel.com>
Subject: Re: [PATCH 3/6] swap: Unify normal/huge code path in swap_page_trans_huge_swapped()
Date: Sat, 14 Jul 2018 20:53:12 +0800 [thread overview]
Message-ID: <87efg6dlmv.fsf@yhuang-dev.intel.com> (raw)
In-Reply-To: <20180713201557.bjt4tj26nisgdmmi@ca-dmjordan1.us.oracle.com> (Daniel Jordan's message of "Fri, 13 Jul 2018 13:15:57 -0700")
Daniel Jordan <daniel.m.jordan@oracle.com> writes:
> On Fri, Jul 13, 2018 at 07:36:33AM +0800, Huang, Ying wrote:
>> diff --git a/mm/swapfile.c b/mm/swapfile.c
>> index 75c84aa763a3..160f78072667 100644
>> --- a/mm/swapfile.c
>> +++ b/mm/swapfile.c
>> @@ -270,7 +270,10 @@ static inline void cluster_set_null(struct swap_cluster_info *info)
>>
>> static inline bool cluster_is_huge(struct swap_cluster_info *info)
>> {
>> - return info->flags & CLUSTER_FLAG_HUGE;
>> + if (IS_ENABLED(CONFIG_THP_SWAP))
>> + return info->flags & CLUSTER_FLAG_HUGE;
>> + else
>> + return false;
>> }
>>
>> static inline void cluster_clear_huge(struct swap_cluster_info *info)
>> @@ -1489,9 +1492,6 @@ static bool swap_page_trans_huge_swapped(struct swap_info_struct *si,
>> int i;
>> bool ret = false;
>>
>> - if (!IS_ENABLED(CONFIG_THP_SWAP))
>> - return swap_swapcount(si, entry) != 0;
>
> This tests the value returned from swap_count,
>
>> -
>> ci = lock_cluster_or_swap_info(si, offset);
>> if (!ci || !cluster_is_huge(ci)) {
>> if (map[roffset] != SWAP_HAS_CACHE)
>
> and now we're testing
>
> map[roffset] != SWAP_HAS_CACHE
>
> instead. The two seem to mean the same thing here, since the swap slot hasn't
> been freed to the global pool and so can't be 0, but it might be better for
> consistency and clarity to use swap_count here, and a few lines down too
>
> for (i = 0; i < SWAPFILE_CLUSTER; i++) {
> if (map[offset + i] != SWAP_HAS_CACHE) {
>
> since swap_count seems to be used everywhere else for this.
Yes. swap_count() looks better here. Will change this.
Best Regards,
Huang, Ying
next prev parent reply other threads:[~2018-07-14 12:53 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-12 23:36 [PATCH 0/6] swap: THP optimizing refactoring Huang, Ying
2018-07-12 23:36 ` [PATCH 1/6] swap: Add comments to lock_cluster_or_swap_info() Huang, Ying
2018-07-13 10:48 ` Dave Hansen
2018-07-14 4:07 ` Huang, Ying
2018-07-12 23:36 ` [PATCH 2/6] mm/swapfile.c: Replace some #ifdef with IS_ENABLED() Huang, Ying
2018-07-13 18:38 ` Daniel Jordan
2018-07-13 18:55 ` Daniel Jordan
2018-07-12 23:36 ` [PATCH 3/6] swap: Unify normal/huge code path in swap_page_trans_huge_swapped() Huang, Ying
2018-07-13 20:15 ` Daniel Jordan
2018-07-14 12:53 ` Huang, Ying [this message]
2018-07-12 23:36 ` [PATCH 4/6] swap: Unify normal/huge code path in put_swap_page() Huang, Ying
2018-07-12 23:36 ` [PATCH 5/6] swap: Add __swap_entry_free_locked() Huang, Ying
2018-07-12 23:36 ` [PATCH 6/6] swap, put_swap_page: Share more between huge/normal code path Huang, Ying
2018-07-13 20:18 ` Daniel Jordan
2018-07-14 12:57 ` Huang, Ying
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