From mboxrd@z Thu Jan 1 00:00:00 1970 From: James A. Sutherland Subject: Re: suspend processes at load (was Re: a simple OOM ...) Date: Thu, 19 Apr 2001 19:47:12 +0100 Message-ID: References: <11530000.987705299@baldur> In-Reply-To: <11530000.987705299@baldur> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8BIT Sender: owner-linux-mm@kvack.org Return-Path: To: Dave McCracken Cc: linux-mm@kvack.org List-ID: On Thu, 19 Apr 2001 13:34:59 -0500, you wrote: >--On Wednesday, April 18, 2001 23:32:25 +0200 Szabolcs Szakacsits > wrote: > >> Sorry, your comment isn't convincing enough ;) Why do you think >> "arbitrarily" (decided exclusively by the kernel itself) suspending >> processes (that can be done in user space anyway) would help? >> >> Even if you block new process creation and memory allocations (that's >> also not nice since it can be done by resource limits) why you think >> situation will ever get better i.e. processes release memory? >> >> How you want to avoid "deadlocks" when running processes have >> dependencies on suspended processes? > >I think there's a semantic misunderstanding here. If I understand Rik's >proposal right, Well, it was my proposal when I first said it :-) >he's not talking about completely suspending a process ala >SIGSTOP. He's talking about removing it from the run queue for some small >length of time (ie a few seconds, probably) during which all the other >processes can make progress. Rik and I are both proposing that, AFAICS; however it's implemented (SIGSTOP or direct tweaking of the run queue; I prefer the former, since I think it could be done more neatly) you just suspend the process for a couple of seconds, then resume it (and suspend someone else if the thrashing continues). >This kind of suspension won't be noticeable >to users/administrators or permanently block dependent processes. In fact, >it should make the system appear more responsive than one in a thrashing >state. Indeed. It would certainly help with the usual test-case for such things ("make -j 50" or similar): you'll end up with 40 gcc processes being frozen at once, allowing the other 10 to complete first. James. -- 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.eu.org/Linux-MM/