From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f169.google.com (mail-pf0-f169.google.com [209.85.192.169]) by kanga.kvack.org (Postfix) with ESMTP id CBFB66B007E for ; Tue, 22 Mar 2016 22:44:04 -0400 (EDT) Received: by mail-pf0-f169.google.com with SMTP id n5so4678392pfn.2 for ; Tue, 22 Mar 2016 19:44:04 -0700 (PDT) Received: from mga01.intel.com (mga01.intel.com. [192.55.52.88]) by mx.google.com with ESMTP id u86si622275pfa.250.2016.03.22.19.44.03 for ; Tue, 22 Mar 2016 19:44:03 -0700 (PDT) Date: Tue, 22 Mar 2016 19:44:02 -0700 From: Andi Kleen Subject: Re: [RFC] high preempt off latency in vfree path Message-ID: <20160323024402.GA27856@tassilo.jf.intel.com> References: <56F1F4A6.2060400@lab126.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <56F1F4A6.2060400@lab126.com> Sender: owner-linux-mm@kvack.org List-ID: To: Joel Fernandes Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, tj@kernel.org, linux-rt-users@vger.kernel.org, Nick Piggin > (1) > One is we reduce the number of lazy_max_pages (right now its around 32MB per core worth of pages). > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index aa3891e..2720f4f 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -564,7 +564,7 @@ static unsigned long lazy_max_pages(void) > > log = fls(num_online_cpus()); > > - return log * (32UL * 1024 * 1024 / PAGE_SIZE); > + return log * (8UL * 1024 * 1024 / PAGE_SIZE); > } This seems like the right fix to me. Perhaps even make it somewhat smaller. Even on larger systems it's probably fine because they have a lot more cores/threads these days, so it will be still sufficiently large. -Andi -- 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-mm.org/ . Don't email: email@kvack.org