linux-kernel - Re: [PATCH 4/5] Use add_page_to_lru

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20090720143352.747E.A69D9226@jp.fujitsu.com>
Date:	Mon, 20 Jul 2009 14:37:09 +0900 (JST)
From:	KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>
To:	Peter Zijlstra <peterz@...radead.org>
Cc:	kosaki.motohiro@...fujitsu.com,
	LKML <linux-kernel@...r.kernel.org>,
	linux-mm <linux-mm@...ck.org>,
	Andrew Morton <akpm@...ux-foundation.org>
Subject: Re: [PATCH 4/5] Use add_page_to_lru_list() helper function

> > @@ -1241,7 +1241,6 @@ static void move_active_pages_to_lru(str
> >  			spin_lock_irq(&zone->lru_lock);
> >  		}
> >  	}
> > -	__mod_zone_page_state(zone, NR_LRU_BASE + lru, pgmoved);
> >  	if (!is_active_lru(lru))
> >  		__count_vm_events(PGDEACTIVATE, pgmoved);
> >  }
> 
> This is a net loss, you introduce pgmoved calls to __inc_zone_state,
> instead of the one __mod_zone_page_state() call.

max pgmoved is 32. 32 times __inc_zone_state() make 0 or 1 time
atomic operation (not much than two).
I don't think it reduce performance.




--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/