public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Nick Piggin <nickpiggin@yahoo.com.au>
To: Andrea Arcangeli <andrea@novell.com>
Cc: Rik van Riel <riel@redhat.com>, Andrew Morton <akpm@osdl.org>,
	linux-kernel@vger.kernel.org
Subject: Re: lowmem_reserve (replaces protection)
Date: Wed, 27 Oct 2004 12:56:44 +1000	[thread overview]
Message-ID: <417F0E6C.60104@yahoo.com.au> (raw)
In-Reply-To: <20041027013522.GR14325@dualathlon.random>

Andrea Arcangeli wrote:
> this _incremental_ 2/? patch should fix the longtanding kswapd issue
> vs protection algorithm, now lowmem_reserve (partly hidden by the lack
> of lowmem_reserve/protection or equivalent band-aid enabled in 2.6.9).
> 
> --- 2-kswapd-balance/include/linux/mmzone.h.~1~	2004-10-27 03:17:07.207812600 +0200
> +++ 2-kswapd-balance/include/linux/mmzone.h	2004-10-27 03:26:22.673369000 +0200
> @@ -273,7 +273,7 @@ void __get_zone_counts(unsigned long *ac
>  void get_zone_counts(unsigned long *active, unsigned long *inactive,
>  			unsigned long *free);
>  void build_all_zonelists(void);
> -void wakeup_kswapd(struct zone *zone);
> +void wakeup_kswapd(struct zone *zone, int classzone_idx);
>  
>  /*
>   * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
> --- 2-kswapd-balance/mm/page_alloc.c.~1~	2004-10-27 03:17:07.215811384 +0200
> +++ 2-kswapd-balance/mm/page_alloc.c	2004-10-27 03:24:31.351292528 +0200
> @@ -641,7 +641,7 @@ __alloc_pages(unsigned int gfp_mask, uns
>  	}
>  
>  	for (i = 0; (z = zones[i]) != NULL; i++)
> -		wakeup_kswapd(z);
> +		wakeup_kswapd(z, classzone_idx);
>  
>  	/*
>  	 * Go through the zonelist again. Let __GFP_HIGH and allocations
> --- 2-kswapd-balance/mm/vmscan.c.~1~	2004-10-27 03:14:22.563842288 +0200
> +++ 2-kswapd-balance/mm/vmscan.c	2004-10-27 03:26:57.462080312 +0200
> @@ -1169,11 +1169,11 @@ static int kswapd(void *p)
>  /*
>   * A zone is low on free memory, so wake its kswapd task to service it.
>   */
> -void wakeup_kswapd(struct zone *zone)
> +void wakeup_kswapd(struct zone *zone, int classzone_idx)
>  {
>  	if (zone->present_pages == 0)
>  		return;
> -	if (zone->free_pages > zone->pages_low)
> +	if (zone->free_pages > zone->pages_low + zone->lowmem_reserve[classzone_idx])
>  		return;
>  	if (!waitqueue_active(&zone->zone_pgdat->kswapd_wait))
>  		return;

I don't think this is required, because by the time __alloc_pages
reaches wakeup_kswapd, it would have checked one zone with a
->lowmem_reserve of 0, and found it to be low on pages. Thus
wakeup_kswapd will wake it up.

  parent reply	other threads:[~2004-10-27  2:57 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-10-25 17:01 lowmem_reserve (replaces protection) Andrea Arcangeli
2004-10-26  1:48 ` Rik van Riel
2004-10-26  1:58   ` Andrea Arcangeli
2004-10-26  3:48     ` Nick Piggin
2004-10-26  4:04       ` Andrea Arcangeli
2004-10-26  4:17         ` Nick Piggin
2004-10-27  0:25           ` Andrea Arcangeli
2004-10-27  0:42             ` Andrew Morton
2004-10-27  0:48               ` Andrea Arcangeli
2004-10-27  2:06             ` Nick Piggin
2004-10-28  0:26             ` Andrea Arcangeli
2004-10-27  0:31           ` Rik van Riel
2004-10-27  0:54             ` Andrea Arcangeli
2004-10-27  0:56               ` Andrea Arcangeli
2004-10-27  1:35                 ` Andrea Arcangeli
2004-10-27  2:08                   ` Andrew Morton
2004-10-27  2:31                     ` Andrea Arcangeli
2004-10-27  2:56                   ` Nick Piggin [this message]
2004-10-27  1:00               ` Rik van Riel
2004-10-27  1:10                 ` Andrea Arcangeli
2004-10-27  2:05               ` Nick Piggin
2004-10-27  2:29                 ` Andrea Arcangeli
2004-10-27  3:01                   ` Nick Piggin
2004-10-27  3:23                     ` Andrea Arcangeli
2004-10-27  3:34                       ` Nick Piggin
2004-10-27  3:43                         ` Andrew Morton
2004-10-27  4:44                           ` Andrea Arcangeli
2004-10-27  4:51                             ` Rik van Riel
2004-10-27  5:05                               ` Andrea Arcangeli
2004-10-27  5:50                                 ` Nick Piggin
2004-10-27  5:33                             ` Andrew Morton
2004-10-27  6:11                               ` Andrea Arcangeli

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=417F0E6C.60104@yahoo.com.au \
    --to=nickpiggin@yahoo.com.au \
    --cc=akpm@osdl.org \
    --cc=andrea@novell.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=riel@redhat.com \
    /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
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox