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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 95CCDC433EF for ; Thu, 28 Apr 2022 05:25:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242963AbiD1F2O (ORCPT ); Thu, 28 Apr 2022 01:28:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52112 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229627AbiD1F2I (ORCPT ); Thu, 28 Apr 2022 01:28:08 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 8655523178 for ; Wed, 27 Apr 2022 22:24:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1651123494; 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: in-reply-to:in-reply-to:references:references; bh=E2WT+5Dj/uF92md4vRvJ45vZd5NBiJcHUWg+Un6DF70=; b=bAf3BZ6QaqgK//q2caMT5ah594EnZT2Jb2yx0WlQz5kZGIMdilaS/65RHmJzhG5/Noqc4A BgvmKO0KGnOf9qIu9QNPXMYN1kQyHayLWGuqdfBrobKlSkbAFkIqbBfl66V4WCjkMflBwc 1KLO2CQjWFUENHPxY3IEp6XCiF+9TNE= Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-220-k7XNWM5_NSeq4MgQ2Mo-MA-1; Thu, 28 Apr 2022 01:24:52 -0400 X-MC-Unique: k7XNWM5_NSeq4MgQ2Mo-MA-1 Received: by mail-wm1-f71.google.com with SMTP id d13-20020a05600c3acd00b0038ff865c043so3854444wms.3 for ; Wed, 27 Apr 2022 22:24:52 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=E2WT+5Dj/uF92md4vRvJ45vZd5NBiJcHUWg+Un6DF70=; b=Vz5ohx+e6zDNy7rP7qPR54oTSdYwzbzSHj53Vq84syy4437Cxk1Tirec54sUIfLxL0 +0984vguOJmX0XUnmJkcsirOIjeFd7HSuA6TZN8hD87r7ltuK8DNadJZwKEy8pfwAZ+e 7FylZUNH+p5ea0OZPis6k4F/Vgh5chzYYL0z+93VI7iBCa4WqbU/PH6Jyr7b5MPi1owb UlDbeGwXtXHmMeA3h1stPZTHbZTky2Vb5POY272Ev+tKp9Gd/o0QzcYDFM1qYdwZ/gjK VX+fReFFP3t0EbtCJ6ilc7PU+lHJYPeSlFzEo09gWMb1myG2+AxVx29OEXtE1VU2OtgP 3CoQ== X-Gm-Message-State: AOAM532BepJaJh/WOe5lSG3HPuK5HhULvWTxQL6R1bgkM8K9AHt9wAgC 7ktljEi0Yi916c7g+mVrHEwNBKJmedwgWYS0CIDSPle7Lw2Q2Bbu8fei2SExpxWmXT66HZ11h7N hamciLC1/JuykER62O94W2Hj5 X-Received: by 2002:adf:dd0e:0:b0:20a:d00a:fcf0 with SMTP id a14-20020adfdd0e000000b0020ad00afcf0mr20082710wrm.239.1651123491569; Wed, 27 Apr 2022 22:24:51 -0700 (PDT) X-Google-Smtp-Source: ABdhPJy1Dc+Z1n8cfxiweI/O1wRWrqc7b8BNVYC1ZGuXlRWcoYm4SDgXmSVs64meStwS7OhANEavmw== X-Received: by 2002:adf:dd0e:0:b0:20a:d00a:fcf0 with SMTP id a14-20020adfdd0e000000b0020ad00afcf0mr20082687wrm.239.1651123491114; Wed, 27 Apr 2022 22:24:51 -0700 (PDT) Received: from redhat.com ([2.53.18.16]) by smtp.gmail.com with ESMTPSA id c12-20020a05600c0a4c00b00381141f4967sm3674279wmq.35.2022.04.27.22.24.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 27 Apr 2022 22:24:49 -0700 (PDT) Date: Thu, 28 Apr 2022 01:24:43 -0400 From: "Michael S. Tsirkin" To: Jason Wang Cc: Halil Pasic , Cornelia Huck , linux-kernel , virtualization , Stefano Garzarella , eperezma , Cindy Lu , Thomas Gleixner , Peter Zijlstra , "Paul E. McKenney" , Marc Zyngier Subject: Re: [PATCH V3 6/9] virtio-ccw: implement synchronize_cbs() Message-ID: <20220428012156-mutt-send-email-mst@kernel.org> References: <20220425233434-mutt-send-email-mst@kernel.org> <20220425233604-mutt-send-email-mst@kernel.org> <20220425235134-mutt-send-email-mst@kernel.org> <20220425235415-mutt-send-email-mst@kernel.org> <87o80n7soq.fsf@redhat.com> <20220426124243-mutt-send-email-mst@kernel.org> <87ilqu7u6w.fsf@redhat.com> <20220428044315.3945e660.pasic@linux.ibm.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 Thu, Apr 28, 2022 at 11:04:41AM +0800, Jason Wang wrote: > > But my guess is that rwlock + some testing for the legacy indicator case > > just to double check if there is a heavy regression despite of our > > expectations to see none should do the trick. > > I suggest this, rwlock (for not airq) seems better than spinlock, but > at worst case it will cause cache line bouncing. But I wonder if it's > noticeable (anyhow it has been used for airq). > > Thanks Which existing rwlock does airq use right now? Can we take it to sync? -- MST