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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 398A0C3DA6B for ; Tue, 30 Aug 2022 19:03:27 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9FA6D8D0002; Tue, 30 Aug 2022 15:03:26 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9A9358D0001; Tue, 30 Aug 2022 15:03:26 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 84B348D0002; Tue, 30 Aug 2022 15:03:26 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 73FF78D0001 for ; Tue, 30 Aug 2022 15:03:26 -0400 (EDT) Received: from smtpin11.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 46BA380492 for ; Tue, 30 Aug 2022 19:03:26 +0000 (UTC) X-FDA: 79857182412.11.FB0287B Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf29.hostedemail.com (Postfix) with ESMTP id D28D7120068 for ; Tue, 30 Aug 2022 19:03:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1661886205; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=EQby0NB5hpgQj+GqJHolGKDs4KWtRxqQy0UgooG1hoY=; b=SnnyF4fjixoT6M+Y5un5a71oJnvBD5+m6E0mo/HPdRR5A4DshpB7X77O77FMJZ3neA0yXG 6SHR7fiSOGJfyqXm0rtdo5CXI4cNo1IQphhbo/d5/thRmwhlKaiwiAd2plUI0iKUrh44Vu cty/2iM7iEezhvB5AzHsZiEY8CdxQWM= Received: from mail-vs1-f69.google.com (mail-vs1-f69.google.com [209.85.217.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-246-bUI1B8TWNRaxo2o-BWYJjw-1; Tue, 30 Aug 2022 15:03:24 -0400 X-MC-Unique: bUI1B8TWNRaxo2o-BWYJjw-1 Received: by mail-vs1-f69.google.com with SMTP id c129-20020a671c87000000b0038ae002e7a6so1662029vsc.14 for ; Tue, 30 Aug 2022 12:03:24 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc; bh=EQby0NB5hpgQj+GqJHolGKDs4KWtRxqQy0UgooG1hoY=; b=fbZy7l163vL8WG96Ww5jGIuR4ORllRHqO48xwG0Oo7/BNCcQo7gxdV48uhpS2UANqj VWKNFxdf79Og3QsdzzbKUqDYwSuGQaDobvh/xkTQ0lZPLIFvThwFV4nkPMRc3w5wc5/0 Z9IDHMqp45caeTwo2K4f5KQZ+YGb9yWDko4g13SDDE3fQLBB8fhgJZCTrnV04iC6c/rq ETh83YP7r13aFJJOeLF1qIow0LrzeCb0UhDSEFqV4B1DNMMoQ8wKZeV3TFdSy6Azzo3U BBXIj+8jAyWscBhLAG35cwVsbdpj6CGLr0woXd7YQ8ZTHk+Lm5VKvvqtGWzmtS5vJ4QD VrjQ== X-Gm-Message-State: ACgBeo0UOb21HMmfEPVqeO6sv70+NEhEmDzlfAlJpBCuC8t9OJvlZJvJ H+0fFrekHy5WRcSIdGMJkTE29uR5gx+B2NVqYRv8/xPTw6vNCK8UMSgoizT9XLRFaqIXfDtF0CE /o0e5RIKuKLERk3cwqR4ahfQQo40= X-Received: by 2002:a67:ec82:0:b0:388:fefa:2467 with SMTP id h2-20020a67ec82000000b00388fefa2467mr5467644vsp.67.1661886202483; Tue, 30 Aug 2022 12:03:22 -0700 (PDT) X-Google-Smtp-Source: AA6agR6RgVEqcXOIimuk8fQ/2gBWAbahxY49CygHusFiJQnbLDynDaEIrKmkIS1JR9YNELmPJHISR6NTZtYKyO9VN0Y= X-Received: by 2002:a67:ec82:0:b0:388:fefa:2467 with SMTP id h2-20020a67ec82000000b00388fefa2467mr5467632vsp.67.1661886202251; Tue, 30 Aug 2022 12:03:22 -0700 (PDT) MIME-Version: 1.0 References: <20220829154805.1205507-1-mlombard@redhat.com> In-Reply-To: From: Maurizio Lombardi Date: Tue, 30 Aug 2022 21:03:11 +0200 Message-ID: Subject: Re: [PATCH RFC] mm: slub: fix flush_cpu_slab()/__free_slab() invocations in task context. To: Sebastian Andrzej Siewior Cc: Vlastimil Babka , linux-mm , David Rientjes , Pekka Enberg , Joonsoo Kim , Andrew Morton , LKML , tglx@linutronix.de X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1661886205; a=rsa-sha256; cv=none; b=it0L3yCM3UiF3B0y/4HaQsUtVd5/1WsrK1ZVUk+4n6KNg0nFcO7q7YiuxNj7jd4MSPXVof MYrN7Ak/QTHZJETHg4ABRThNfx4FCSi8rMks+RUIYe+e3NuaNjqPaQQHnZD4swkkg+1Ley mwLYDbG5tfHAJoRKl6dcKc8SBIBd6ic= ARC-Authentication-Results: i=1; imf29.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=SnnyF4fj; spf=pass (imf29.hostedemail.com: domain of mlombard@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=mlombard@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1661886205; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=EQby0NB5hpgQj+GqJHolGKDs4KWtRxqQy0UgooG1hoY=; b=4u+4PkzZAaMk7IPgowcjkXG9Ifls3NybE5gYi1d7lk+FXE3ja05xncM3CVB6eCfSfUPYeD fZdoZ15vGRUujBweMFYjeKYOORnmVuPE0LNRkupIR03ZCzMO2X9nT4NBzkKRsdsvwk/OOb GETE3ApIwxou1kTP+MC31WR5lwJhoC4= X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: D28D7120068 X-Rspam-User: Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=SnnyF4fj; spf=pass (imf29.hostedemail.com: domain of mlombard@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=mlombard@redhat.com; dmarc=pass (policy=none) header.from=redhat.com X-Stat-Signature: h74aqr3ts4wr73tapagsrphepuj1r1u8 X-HE-Tag: 1661886205-9748 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000183, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: =C3=BAt 30. 8. 2022 v 20:59 odes=C3=ADlatel Sebastian Andrzej Siewior napsal: > > On 2022-08-30 17:48:06 [+0200], Maurizio Lombardi wrote: > > Hmm, this is not good indeed. I guess I should have used for_each_onlin= e_cpu() > > instead of on_each_cpu_cond(). > > But you must not invoked that function cross-CPU since the code expects > to access the per-CPU variables always from the local-CPU. Ok, thanks for the clarification. > > > > > > > Couldn't we instead use a workqueue with that WQ_MEM_RECLAIM bit? It = may > > > reclaim memory after all ;) > > > > That should also fix it, do you think it would be ok to allocate a work= queue in > > in kmem_cache_init() ? > > I guess so. There is probably none that is already available. > Will test it and submit a patch soon. Thanks, Maurizio