Linux-Fsdevel Archive on lore.kernel.org
 help / color / Atom feed
From: Jan Kara <jack@suse.cz>
To: Mel Gorman <mgorman@techsingularity.net>
Cc: Linux-MM <linux-mm@kvack.org>,
	Linux-FSDevel <linux-fsdevel@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>, Jan Kara <jack@suse.cz>,
	Andi Kleen <ak@linux.intel.com>,
	Dave Hansen <dave.hansen@intel.com>,
	Dave Chinner <david@fromorbit.com>
Subject: Re: [PATCH 2/8] mm, truncate: Do not check mapping for every page being truncated
Date: Thu, 12 Oct 2017 14:15:27 +0200
Message-ID: <20171012121527.GA29293@quack2.suse.cz> (raw)
In-Reply-To: <20171012093103.13412-3-mgorman@techsingularity.net>

On Thu 12-10-17 10:30:57, Mel Gorman wrote:
> During truncation, the mapping has already been checked for shmem and dax
> so it's known that workingset_update_node is required. This patch avoids
> the checks on mapping for each page being truncated. In all other cases,
> a lookup helper is used to determine if workingset_update_node() needs
> to be called. The one danger is that the API is slightly harder to use as
> calling workingset_update_node directly without checking for dax or shmem
> mappings could lead to surprises. However, the API rarely needs to be used
> and hopefully the comment is enough to give people the hint.
> 
> sparsetruncate (tiny)
>                               4.14.0-rc4             4.14.0-rc4
>                              oneirq-v1r1        pickhelper-v1r1
> Min          Time      141.00 (   0.00%)      140.00 (   0.71%)
> 1st-qrtle    Time      142.00 (   0.00%)      141.00 (   0.70%)
> 2nd-qrtle    Time      142.00 (   0.00%)      142.00 (   0.00%)
> 3rd-qrtle    Time      143.00 (   0.00%)      143.00 (   0.00%)
> Max-90%      Time      144.00 (   0.00%)      144.00 (   0.00%)
> Max-95%      Time      147.00 (   0.00%)      145.00 (   1.36%)
> Max-99%      Time      195.00 (   0.00%)      191.00 (   2.05%)
> Max          Time      230.00 (   0.00%)      205.00 (  10.87%)
> Amean        Time      144.37 (   0.00%)      143.82 (   0.38%)
> Stddev       Time       10.44 (   0.00%)        9.00 (  13.74%)
> Coeff        Time        7.23 (   0.00%)        6.26 (  13.41%)
> Best99%Amean Time      143.72 (   0.00%)      143.34 (   0.26%)
> Best95%Amean Time      142.37 (   0.00%)      142.00 (   0.26%)
> Best90%Amean Time      142.19 (   0.00%)      141.85 (   0.24%)
> Best75%Amean Time      141.92 (   0.00%)      141.58 (   0.24%)
> Best50%Amean Time      141.69 (   0.00%)      141.31 (   0.27%)
> Best25%Amean Time      141.38 (   0.00%)      140.97 (   0.29%)
> 
> As you'd expect, the gain is marginal but it can be detected. The differences
> in bonnie are all within the noise which is not surprising given the impact
> on the microbenchmark.
> 
> Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
...
> diff --git a/mm/workingset.c b/mm/workingset.c
> index 7119cd745ace..a80d52387734 100644
> --- a/mm/workingset.c
> +++ b/mm/workingset.c
> @@ -341,12 +341,6 @@ static struct list_lru shadow_nodes;
>  
>  void workingset_update_node(struct radix_tree_node *node, void *private)
>  {
> -	struct address_space *mapping = private;
> -
> -	/* Only regular page cache has shadow entries */
> -	if (dax_mapping(mapping) || shmem_mapping(mapping))
> -		return;
> -

Hum, we don't need to pass 'mapping' from call sites then? Either pass NULL
or just remove the argument completely since nobody needs it anymore...
Otherwise the patch looks good.

								Honza

-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

  reply index

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-10-12  9:30 [PATCH 0/8] Follow-up for speed up page cache truncation Mel Gorman
2017-10-12  9:30 ` [PATCH 1/8] mm, page_alloc: Enable/disable IRQs once when freeing a list of pages Mel Gorman
2017-10-12  9:30 ` [PATCH 2/8] mm, truncate: Do not check mapping for every page being truncated Mel Gorman
2017-10-12 12:15   ` Jan Kara [this message]
2017-10-12 12:41     ` Mel Gorman
2017-10-12 19:11   ` Johannes Weiner
2017-10-12  9:30 ` [PATCH 3/8] mm, truncate: Remove all exceptional entries from pagevec under one lock Mel Gorman
2017-10-12 13:33   ` Jan Kara
2017-10-12 14:53     ` Mel Gorman
2017-10-12 19:45   ` Johannes Weiner
2017-10-12  9:30 ` [PATCH 4/8] mm: Only drain per-cpu pagevecs once per pagevec usage Mel Gorman
2017-10-12  9:31 ` [PATCH 5/8] mm, pagevec: Remove cold parameter for pagevecs Mel Gorman
2017-10-12  9:31 ` [PATCH 6/8] mm: Remove cold parameter for release_pages Mel Gorman
2017-10-12  9:31 ` [PATCH 7/8] mm, Remove cold parameter from free_hot_cold_page* Mel Gorman
2017-10-12  9:31 ` [PATCH 8/8] mm: Remove __GFP_COLD Mel Gorman
2017-10-18  7:59 [PATCH 0/8] Follow-up for speed up page cache truncation v2 Mel Gorman
2017-10-18  7:59 ` [PATCH 2/8] mm, truncate: Do not check mapping for every page being truncated Mel Gorman
2017-10-19  8:11   ` Jan Kara

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20171012121527.GA29293@quack2.suse.cz \
    --to=jack@suse.cz \
    --cc=ak@linux.intel.com \
    --cc=dave.hansen@intel.com \
    --cc=david@fromorbit.com \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mgorman@techsingularity.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-Fsdevel Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-fsdevel/0 linux-fsdevel/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-fsdevel linux-fsdevel/ https://lore.kernel.org/linux-fsdevel \
		linux-fsdevel@vger.kernel.org
	public-inbox-index linux-fsdevel

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-fsdevel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git