All of lore.kernel.org
 help / color / mirror / Atom feed
From: Andi Kleen <andi@firstfloor.org>
To: Mel Gorman <mgorman@techsingularity.net>
Cc: "Huang\, Ying" <ying.huang@intel.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	tim.c.chen@intel.com, dave.hansen@intel.com,
	andi.kleen@intel.com, aaron.lu@intel.com, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org, Hugh Dickins <hughd@google.com>,
	Shaohua Li <shli@kernel.org>, Minchan Kim <minchan@kernel.org>,
	Rik van Riel <riel@redhat.com>, Tejun Heo <tj@kernel.org>,
	Wu Fengguang <fengguang.wu@intel.com>
Subject: Re: [PATCH -v2] mm: Don't use radix tree writeback tags for pages in swap cache
Date: Wed, 31 Aug 2016 14:35:11 -0700	[thread overview]
Message-ID: <87vaygzkog.fsf@tassilo.jf.intel.com> (raw)
In-Reply-To: <20160831153908.GA8119@techsingularity.net> (Mel Gorman's message of "Wed, 31 Aug 2016 16:39:08 +0100")

Mel Gorman <mgorman@techsingularity.net> writes:
>
> __GFP_BITS_SHIFT + 5 (AS_NO_WRITEBACK_TAGS) = 31
>
> mapping->flags is a combination of AS and GFP flags so increasing
> __GFP_BITS_SHIFT overflows mapping->flags on 32-bit as gfp_t is an
> unsigned int.

Couldn't we just split mapping->flags into two fields?
I'm sure more GFP bits will be needed eventually.

-Andi

WARNING: multiple messages have this Message-ID
From: Andi Kleen <andi@firstfloor.org>
To: Mel Gorman <mgorman@techsingularity.net>
Cc: "Huang, Ying" <ying.huang@intel.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	tim.c.chen@intel.com, dave.hansen@intel.com,
	andi.kleen@intel.com, aaron.lu@intel.com, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org, Hugh Dickins <hughd@google.com>,
	Shaohua Li <shli@kernel.org>, Minchan Kim <minchan@kernel.org>,
	Rik van Riel <riel@redhat.com>, Tejun Heo <tj@kernel.org>,
	Wu Fengguang <fengguang.wu@intel.com>
Subject: Re: [PATCH -v2] mm: Don't use radix tree writeback tags for pages in swap cache
Date: Wed, 31 Aug 2016 14:35:11 -0700	[thread overview]
Message-ID: <87vaygzkog.fsf@tassilo.jf.intel.com> (raw)
In-Reply-To: <20160831153908.GA8119@techsingularity.net> (Mel Gorman's message of "Wed, 31 Aug 2016 16:39:08 +0100")

Mel Gorman <mgorman@techsingularity.net> writes:
>
> __GFP_BITS_SHIFT + 5 (AS_NO_WRITEBACK_TAGS) = 31
>
> mapping->flags is a combination of AS and GFP flags so increasing
> __GFP_BITS_SHIFT overflows mapping->flags on 32-bit as gfp_t is an
> unsigned int.

Couldn't we just split mapping->flags into two fields?
I'm sure more GFP bits will be needed eventually.

-Andi

--
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>

  parent reply	other threads:[~2016-08-31 21:35 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-08-30 17:28 Huang, Ying
2016-08-30 17:28 ` Huang, Ying
2016-08-30 18:29 ` Rik van Riel
2016-08-31  9:14 ` Mel Gorman
2016-08-31  9:14   ` Mel Gorman
2016-08-31 15:17   ` Huang, Ying
2016-08-31 15:17     ` Huang, Ying
2016-08-31 15:39     ` Mel Gorman
2016-08-31 15:39       ` Mel Gorman
2016-08-31 15:44       ` Huang, Ying
2016-08-31 15:44         ` Huang, Ying
2016-08-31 21:35       ` Andi Kleen [this message]
2016-08-31 21:35         ` Andi Kleen
2016-08-31 21:30   ` Andrew Morton
2016-08-31 21:30     ` Andrew Morton
2016-09-01  8:51     ` Mel Gorman
2016-09-01  8:51       ` Mel Gorman
2016-09-01  9:13     ` Michal Hocko
2016-09-01  9:13       ` Michal Hocko
2016-09-12 11:16       ` [PATCH 0/2] do not squash mapping flags and gfp_mask together (was: Re: [PATCH -v2] mm: Don't use radix tree writeback tags for pages in) Michal Hocko
2016-09-12 11:16         ` Michal Hocko
2016-09-12 11:16         ` [PATCH 1/2] fs: use mapping_set_error instead of opencoded set_bit Michal Hocko
2016-09-12 11:16           ` Michal Hocko
2016-09-12 22:11           ` Andrew Morton
2016-09-12 22:11             ` Andrew Morton
2016-09-12 22:18             ` Andrew Morton
2016-09-12 22:18               ` Andrew Morton
2016-09-13  6:53               ` Michal Hocko
2016-09-13  6:53                 ` Michal Hocko
2016-09-13 21:29                 ` Andrew Morton
2016-09-13 21:29                   ` Andrew Morton
2016-09-12 11:16         ` [PATCH 2/2] mm: split gfp_mask and mapping flags into separate fields Michal Hocko
2016-09-12 11:16           ` Michal Hocko
2016-09-12 11:48           ` Michal Hocko
2016-09-12 11:48             ` Michal Hocko

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=87vaygzkog.fsf@tassilo.jf.intel.com \
    --to=andi@firstfloor.org \
    --cc=aaron.lu@intel.com \
    --cc=akpm@linux-foundation.org \
    --cc=andi.kleen@intel.com \
    --cc=dave.hansen@intel.com \
    --cc=fengguang.wu@intel.com \
    --cc=hughd@google.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mgorman@techsingularity.net \
    --cc=minchan@kernel.org \
    --cc=riel@redhat.com \
    --cc=shli@kernel.org \
    --cc=tim.c.chen@intel.com \
    --cc=tj@kernel.org \
    --cc=ying.huang@intel.com \
    --subject='Re: [PATCH -v2] mm: Don'\''t use radix tree writeback tags for pages in swap cache' \
    /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

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.