From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EC05DC433EF for ; Wed, 22 Sep 2021 11:28:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CDAD661156 for ; Wed, 22 Sep 2021 11:28:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235696AbhIVLaA (ORCPT ); Wed, 22 Sep 2021 07:30:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42496 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235422AbhIVL36 (ORCPT ); Wed, 22 Sep 2021 07:29:58 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D25D5C061574; Wed, 22 Sep 2021 04:28:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=D7ZSl4YWEnGCJruUgFbe6upY9ZIlVKrfq0rf1wn9qT4=; b=bpBVu4IjgGl0Zdm/lkC2DT5zDD IhqLDeZhP/xM0SbN4iNNX7YYqL9GuSxmrTDAaLhFK27VashqlEnQ2VXBC0Lfp0Wvvl/sXmsnb+ugw hfyQjy61RtFfG2mwcw3i/dWbKC1UkAxey2W/3bolaSXZjkN3F9ND/B0R3rV6TCUDUV62Y4g2HW8jf Ul15D8IR+ZtAwEcVkNEQgKADdTCzvPqIUtyKaJLv1idSFLkeq5yAWbHuG0u/dsKc3qkHDieX7c50o UjFf2lfi2EK8du47kNWIO40f3sGcSmrix9/myZOWr7pqXuTWFlttdRQHMn7gt6+ROw3vY9bP5njv3 YAM+81pA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=worktop.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1mT0QE-004yj0-Li; Wed, 22 Sep 2021 11:28:18 +0000 Received: by worktop.programming.kicks-ass.net (Postfix, from userid 1000) id 493529816EA; Wed, 22 Sep 2021 13:28:17 +0200 (CEST) Date: Wed, 22 Sep 2021 13:28:17 +0200 From: Peter Zijlstra To: Vlastimil Babka Cc: Nicolas Saenz Julienne , akpm@linux-foundation.org, frederic@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, tglx@linutronix.de, cl@linux.com, juri.lelli@redhat.com, mingo@redhat.com, mtosatti@redhat.com, nilal@redhat.com, mgorman@suse.de, ppandit@redhat.com, williams@redhat.com, bigeasy@linutronix.de, anna-maria@linutronix.de, linux-rt-users@vger.kernel.org Subject: Re: [PATCH 0/6] mm: Remote LRU per-cpu pagevec cache/per-cpu page list drain support Message-ID: <20210922112817.GO4323@worktop.programming.kicks-ass.net> References: <20210921161323.607817-1-nsaenzju@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 21, 2021 at 07:59:51PM +0200, Vlastimil Babka wrote: > These days the pcplist protection is done by local_lock, which solved > the RT concerns. Probably a stupid/infeasible idea, but maybe what you > want to achieve could be more generally solved at the local_lock level? > That on NOHZ_FULL CPUs, local_locks could have this mode where they > could synchronize with remote cpus? local_lock and spinlock have different rules, local_lock for example can never cause an irq inversion, unlike a spinlock.