From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from max.phys.uu.nl (max.phys.uu.nl [131.211.32.73]) by kvack.org (8.8.7/8.8.7) with ESMTP id QAA32244 for ; Tue, 22 Dec 1998 16:51:05 -0500 Date: Tue, 22 Dec 1998 21:10:57 +0100 (CET) From: Rik van Riel Reply-To: Rik van Riel Subject: Re: New patch (was Re: [PATCH] swapin readahead v3 + kswapd fixes) In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Andrea Arcangeli Cc: "Eric W. Biederman" , Linus Torvalds , "Stephen C. Tweedie" , Linux MM , Alan Cox List-ID: On Tue, 22 Dec 1998, Andrea Arcangeli wrote: > On 22 Dec 1998, Eric W. Biederman wrote: > > >My suggestion (again) would be to not call shrink_mmap in the swapper > >(unless we are endangering atomic allocations). And to never call > >swap_out in the memory allocator (just wake up kswapd). > > Ah, I just had your _same_ _exactly_ idea yesterday but there' s a > good reason I nor proposed/tried it. The point are Real time > tasks. kswapd is not realtime and a realtime task must be able to > swapout a little by itself in try_to_free_pages() when there's > nothing to free on the cache anymore. - kswapd should make sure that there is enough on the cache (we should keep track of how many 1-count cache pages there are in the system) - realtime tasks shouldn't go around allocating huge amounts of memory -- this totally ruins the realtime aspect anyway > (and this will avoid also tasks other than kswapd to > sleep waiting for slowww SYNC IO). Some tasks (really big memory hogs) are better left sleeping for I/O because they otherwise completely overpower the rest of the system. But that's a slightly different story :) cheers, Rik -- the flu hits, the flu hits, the flu hits -- MORE +-------------------------------------------------------------------+ | Linux memory management tour guide. H.H.vanRiel@phys.uu.nl | | Scouting Vries cubscout leader. http://www.phys.uu.nl/~riel/ | +-------------------------------------------------------------------+ -- This is a majordomo managed list. To unsubscribe, send a message with the body 'unsubscribe linux-mm me@address' to: majordomo@kvack.org