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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 47697C4360F for ; Tue, 2 Apr 2019 13:56:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1155D20882 for ; Tue, 2 Apr 2019 13:56:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="km5FYIM2" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732178AbfDBN4V (ORCPT ); Tue, 2 Apr 2019 09:56:21 -0400 Received: from mail-io1-f67.google.com ([209.85.166.67]:38575 "EHLO mail-io1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731186AbfDBN4U (ORCPT ); Tue, 2 Apr 2019 09:56:20 -0400 Received: by mail-io1-f67.google.com with SMTP id v4so10964438ioj.5; Tue, 02 Apr 2019 06:56:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=eyIe8u6Gr9VYhYSE410erruSd8jDIrKaP8cUiBOsxSQ=; b=km5FYIM27ScmBGI8oKFEVytngyHRxu4jyDItUvdOhornWRoka5QMu9V8eEaT97vSeI VhSbsmvjbSNd8pRBsc0SC1vADlXEJA03fwnydA+JB1DH9/dkxd8eWy60iCvwjxJh2wZj 56DcVz5ZE2X01/76Zm+DqnfoHONW6hTGkcGjPqvrSGeq0n3KPEfVAF5sMxOYVX8Usuqi 1XKwsJkgmzjFwFuhjz5OIIXvUjTF96x17F6Ey9G8tgANFrUf0SCSsWYqTBLpTpcIVQM8 26nheNiJlG5hj3cA0RN2LJ1xuEzZc4fBM4wd26loHSUxaa7STv7RC9Ea+MrBNIJZt+5s BQeA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=eyIe8u6Gr9VYhYSE410erruSd8jDIrKaP8cUiBOsxSQ=; b=HUnGFxdat3OEoY4zn9y/xBYF0Nf1W2N8kVGeF95eFPTkfmSx4AP+LaiWw456f5hJmS vz4yK4o+b+WfGBsoZBHdDtxdCzQ58+4AKUnQ2llCnV+d84079//alQ8suMFgJKgOPP7J C9DvPn+x8rsTYgPB/o4PuLDn32pzYCCWInoHyLCWxVwgU/acGm4DPleds0OKYleBesdq Ev5pVZeTp6qpGLrKMCpKgNsyAyL/um4SlKPBFJqYW5H5CmHzDtg54rwxtj+Tso0IymJg tTv6GPPNWDUQYuJ4EeOIQptej7zeDiRQGStab9QWOJuRnHwasMwidq5ela8CaCfrLo9M ScpA== X-Gm-Message-State: APjAAAVP8vuhCRWRLvmi3UkLvwKdaaLG+xsIFtLnxkx5i5TfDz9P+BFa LidwSOV3y1z2nBzfKYgpJUmNeaGTe46GVOt0514= X-Google-Smtp-Source: APXvYqy+DqS914UWXRpYWBKcUTv9FxWUFXybOqQw6QZmmMpKDje5XoI4jfNoz7t+dNC7223acJkq1Uhr8dla1yWw4bw= X-Received: by 2002:a6b:8d87:: with SMTP id p129mr48072633iod.10.1554213379755; Tue, 02 Apr 2019 06:56:19 -0700 (PDT) MIME-Version: 1.0 References: <20190402105006.48f93e53@canb.auug.org.au> <20190402112656.GE22763@bombadil.infradead.org> In-Reply-To: <20190402112656.GE22763@bombadil.infradead.org> From: Qiang Yu Date: Tue, 2 Apr 2019 21:56:08 +0800 Message-ID: Subject: Re: linux-next: build failure after merge of the drm-misc tree To: Matthew Wilcox Cc: Stephen Rothwell , Daniel Vetter , Intel Graphics , DRI , Linux Next Mailing List , Linux Kernel Mailing List , Eric Anholt Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 2, 2019 at 7:26 PM Matthew Wilcox wrote: > > On Tue, Apr 02, 2019 at 01:55:03PM +0800, Qiang Yu wrote: > > Thanks, patch is: > > Reviewed-by: Qiang Yu > > This looks like a fairly naive conversion from the old IDR API to the > XArray API. You should be able to remove mgr->lock entirely, relying on > the xa_lock for synchronising free and get. I'm afraid the a little complex free path may involve some might sleep functions so use a mutex lock instead of spinlock. > If you think it's worth it, > you could even use kfree_rcu() to free the ctx and kref_get_unless_zero() > and then your get path would be lock-free. I can take a look this way, thanks.