From: Daniel Jordan <daniel.m.jordan@oracle.com>
To: Huang Ying <ying.huang@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Daniel Jordan <daniel.m.jordan@oracle.com>,
Michal Hocko <mhocko@suse.com>, Minchan Kim <minchan@kernel.org>,
Tim Chen <tim.c.chen@linux.intel.com>,
Hugh Dickins <hughd@google.com>
Subject: Re: [PATCH -V2] swap: Reduce lock contention on swap cache from swap slots allocation
Date: Thu, 21 May 2020 09:35:32 -0400 [thread overview]
Message-ID: <20200521133532.psckytr456eevs5j@ca-dmjordan1.us.oracle.com> (raw)
In-Reply-To: <20200520031502.175659-1-ying.huang@intel.com>
On Wed, May 20, 2020 at 11:15:02AM +0800, Huang Ying wrote:
> @@ -2827,6 +2865,11 @@ static struct swap_info_struct *alloc_swap_info(void)
> p = kvzalloc(struct_size(p, avail_lists, nr_node_ids), GFP_KERNEL);
> if (!p)
> return ERR_PTR(-ENOMEM);
> + p->cluster_next_cpu = alloc_percpu(unsigned int);
> + if (!p->cluster_next_cpu) {
> + kvfree(p);
> + return ERR_PTR(-ENOMEM);
> + }
There should be free_percpu()s at two places after this, but I think the
allocation really belongs right...
> @@ -3202,7 +3245,10 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
> * select a random position to start with to help wear leveling
> * SSD
> */
> - p->cluster_next = 1 + prandom_u32_max(p->highest_bit);
...here because then it's only allocated when it's actually used.
> + for_each_possible_cpu(cpu) {
> + per_cpu(*p->cluster_next_cpu, cpu) =
> + 1 + prandom_u32_max(p->highest_bit);
> + }
> nr_cluster = DIV_ROUND_UP(maxpages, SWAPFILE_CLUSTER);
>
> cluster_info = kvcalloc(nr_cluster, sizeof(*cluster_info),
> --
> 2.26.2
>
>
next prev parent reply other threads:[~2020-05-21 13:37 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-20 3:15 [PATCH -V2] swap: Reduce lock contention on swap cache from swap slots allocation Huang Ying
2020-05-21 2:51 ` Andrew Morton
2020-05-21 3:24 ` Huang, Ying
2020-06-24 3:31 ` Huang, Ying
2020-05-21 13:35 ` Daniel Jordan [this message]
2020-05-22 5:58 ` Huang, Ying
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