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=-2.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_MUTT 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 86CB3C4360F for ; Tue, 19 Feb 2019 23:53:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3A6F92087B for ; Tue, 19 Feb 2019 23:53:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca header.b="XhwxZm6J" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729973AbfBSXxx (ORCPT ); Tue, 19 Feb 2019 18:53:53 -0500 Received: from mail-pl1-f176.google.com ([209.85.214.176]:42414 "EHLO mail-pl1-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727476AbfBSXxw (ORCPT ); Tue, 19 Feb 2019 18:53:52 -0500 Received: by mail-pl1-f176.google.com with SMTP id s1so11201350plp.9 for ; Tue, 19 Feb 2019 15:53:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; h=date:from:to:cc:subject:message-id:mime-version:content-disposition :user-agent; bh=RVTkpac01g3cNfe4Xc4xF+D8LtAtD2ekFLf0SwyqwAM=; b=XhwxZm6J8Hl/tfw1PuOFnkOWuv4pOqCleFp0ncPJuBuObZNAPTkXlKNTyQH/IzZdFf zdfwVujZs9TFDjhsi9sZirh7a8aTZmbbHc/TaSJ698au3Y9Fu+RJCM3EE4Rosu0/OXY0 Tjs5xPnvdTGoxVUNQVhkbtyoAa8ZR0wmnHmQ95pIKkgPR6JWrqDDMUY1c90GDo2qUf2u flZFDW6HHHnXgknGRBqvwcvsal0Qi9DNvYIUHVaoB6Sm+p673VmPqDZ9PtC7tiivM/Qv zwYlYYLEPVVhKuDe3YIJiYJ0UlO/gjyboowcHxgqrXunZgzk6h0qS/cXCagGqrGYtgU7 B/FQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:mime-version :content-disposition:user-agent; bh=RVTkpac01g3cNfe4Xc4xF+D8LtAtD2ekFLf0SwyqwAM=; b=lgeA/EN4mUt2jecq6IVPjXRod6CG8MbV4FL3mCJxfNv7JeltS+e6zTHUL+0Mfyw0zi 28kgl2L0r1/CQ+IggF0aysNXlCY2mik6dSJjbcU6/Md6JdLGBdeiSdSv1ZGR3+2ulClS 2UUQYvMaqPa36OxZYkSBoNowOXHakEVv/L0YkZDhneDv3tAwHGwYZo57dqempjvZcBHX S06QCnBfcoCGzQhD2GNKEUN31/fJdywrWfCStaxzOc+x066MoWEkbJI4dNHSflTG+fgY M3THkuA8usV7stL0D2JJ2nwWDoj6b/zgSxdT9pOGn01YZFMSc6HzIxDzAmS9UsEFie13 9oBg== X-Gm-Message-State: AHQUAuYDijHCLKP4ezN6OjjCwIXenJg1i30u2zocrX3LbNKUX8tebU/9 NqwjbdooHpk+gRb5tgcBLD/eoQ== X-Google-Smtp-Source: AHgI3IYRY6d0eUH61qZaCykgm5rbBAhJxTk+g2Av1/9Er8Pn4n0rpVkPCGpzzuToyQ6svK19WT7G7g== X-Received: by 2002:a17:902:2a66:: with SMTP id i93mr33778640plb.128.1550620431769; Tue, 19 Feb 2019 15:53:51 -0800 (PST) Received: from ziepe.ca (S010614cc2056d97f.ed.shawcable.net. [174.3.196.123]) by smtp.gmail.com with ESMTPSA id y5sm29416041pge.49.2019.02.19.15.53.50 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 19 Feb 2019 15:53:51 -0800 (PST) Received: from jgg by mlx.ziepe.ca with local (Exim 4.90_1) (envelope-from ) id 1gwFCv-0004Zb-Rb; Tue, 19 Feb 2019 16:53:49 -0700 Date: Tue, 19 Feb 2019 16:53:49 -0700 From: Jason Gunthorpe To: Matthew Wilcox Cc: linux-kernel@vger.kernel.org Subject: xarray reserve/release? Message-ID: <20190219235349.GA17351@ziepe.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hey Matt, Did you intend that xa_release doesn't work on allocating arrays: xa_init_flags(&xa, XA_FLAGS_ALLOC); xa_reserve(&xa, 0, GFP_KERNEL); WARN_ON(xa_empty(&xa)); xa_release(&xa, 0); WARN_ON(!xa_empty(&xa)); Triggers the second WARN_ON. If FLAGS_ALLOC is removed this passes This creates kind of a confusing / super unexpected situation where xa_for_each (xa, id) xa_erase(xa, id); WARN_ON(!xa_empty(&xa)) Is not safe with XA_FLAGS_ALLOC?? Seems like at least deserves a documentation note.. Or maybe ALLOC xa_empty should do something different? Thanks, Jason