From mboxrd@z Thu Jan 1 00:00:00 1970 From: William Lee Irwin III Date: Sat, 06 Nov 2004 20:05:09 +0000 Subject: Re: removing mm->rss and mm->anon_rss from kernel? Message-Id: <20041106200509.GG2890@holomorphy.com> List-Id: References: <4189EC67.40601@yahoo.com.au> <418AD329.3000609@yahoo.com.au> <418AE0F0.5050908@yahoo.com.au> <418C55A7.9030100@yahoo.com.au> <204290000.1099754257@[10.10.2.4]> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Christoph Lameter Cc: Nick Piggin , Benjamin Herrenschmidt , Hugh Dickins , linux-mm@kvack.org, linux-ia64@vger.kernel.org On Sat, Nov 06, 2004 at 08:19:55AM -0800, Christoph Lameter wrote: > Yes but I think this is preferable because of the generally faster > operations of the vm without having to continually update statistics. And > these statistics seem to be quite difficult to properly generate (why else > introduce anon_rss). Without the counters other optimizations are easier > to do. > Doing a ps is not a frequent event. Of course this may cause > significant load if one does regularly access /proc entities then. Are > there any threads from the past with some numbers of what the impact was > when we calculated rss via proc? It was catastrophic. Failure of monitoring tools to make forward progress, long-lived delays of "victim" processes whose locks were held by /proc/ observers, and the like. On Sat, Nov 06, 2004 at 08:19:55AM -0800, Christoph Lameter wrote: > That has its own complications and would require lots of memory with > systems that already have up to 10k cpus. Split counters are a solved problem, even for the 10K cpus case. -- wli