From owner-svn-src-head@freebsd.org Mon Aug 6 09:33:34 2018 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 50FAC10510D9; Mon, 6 Aug 2018 09:33:34 +0000 (UTC) (envelope-from mjguzik@gmail.com) Received: from mail-qk0-x22e.google.com (mail-qk0-x22e.google.com [IPv6:2607:f8b0:400d:c09::22e]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id E2FD870AB4; Mon, 6 Aug 2018 09:33:33 +0000 (UTC) (envelope-from mjguzik@gmail.com) Received: by mail-qk0-x22e.google.com with SMTP id 27-v6so8426628qkv.0; Mon, 06 Aug 2018 02:33:33 -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=yWdsdcZxATzt2n0aqv6kQyY01hfXHhmqOK7mmyk363A=; b=j4Q0KOM7sLep42Gc4IVCCwTPU1t9JuAySrjb1+qveGBZnHeeSZoKbbZe3/nn5/UiUF sayeZYqOlza59lrfDE11M1+vUowtdJo/Z4GRifJWwgibHg2YzKV4LWMr+LWIi7dU97z6 dsSZbPfPd0t0dnf/ifxO5XH65hgTOrjDt81i0fRREavt4VVSrrfPrzuaCmq0rqpKUsfo 6Uxw7F3YrtG9nQ2J4SuIT90d8csvX0K80MEWvebcINyalgk9Ak64NG2Hwntwxe6dbVeI SQgZRUNYYgJyQ66zcXgLO/9WNKMjMnNJjqULBlbFTeH8j0qM/4hMw0ZZHunVESmzER13 /zGA== 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=yWdsdcZxATzt2n0aqv6kQyY01hfXHhmqOK7mmyk363A=; b=t9+PUhyNuLkZx0LRs7XNLih6o64Glf7SPzVuP8TD/T5tPNQDMLc9xZY217iRIDV14c 5l90R+frhznYMLl2vIWfI5QAQSyF6Y+octIDW8F27OAKaC3DTr+fM6Mgl9W3sZ1ZT/ql h7szAsYX2/QfzIDcfN49+qVCgynmoNIR7KMH/EOxmHf3btDVP7i7zqUqRtrM7d/yZ+jm eLuG4pWRTRlULdSPEWV2BgQppg+LxC4+oFIJmldBbxNoREZ8EEiSMfghsN8Fkeq0MEvY MYOJgT4qRtbPPttTEmOuW9/AUr60ZLCm8bqbHIv7nVRnehcSACue9JsMgXjxWYLD6OoJ tKuQ== X-Gm-Message-State: AOUpUlGiKtQp6hlWv6FB+49ABZgzP8L2JRGm465Wa0PM/i+TCUUCmdfS iKHTSIS7/uaxXsZk9oW+DWUhu8NvK/pmz2V8pSmIOWs6 X-Google-Smtp-Source: AAOMgpecVHigZwB6ee+NTz12sk0IeujedE3DNvGFWgtsF/M2cBBv5nzTXjAKHXw+utqrg3YiFlgIJps3B0sNl3NLXO8= X-Received: by 2002:a37:3c84:: with SMTP id j126-v6mr12724077qka.73.1533548013472; Mon, 06 Aug 2018 02:33:33 -0700 (PDT) MIME-Version: 1.0 References: <201808060840.w768e2gl023307@repo.freebsd.org> In-Reply-To: <201808060840.w768e2gl023307@repo.freebsd.org> From: Mateusz Guzik Date: Mon, 6 Aug 2018 11:33:05 +0200 Message-ID: Subject: Re: svn commit: r337374 - head/sys/compat/linuxkpi/common/include/asm To: Hans Petter Selasky Cc: src-committers , svn-src-all@freebsd.org, svn-src-head@freebsd.org Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.27 X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.27 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 06 Aug 2018 09:33:34 -0000 On Mon, Aug 6, 2018 at 10:40 AM Hans Petter Selasky wrote: > Author: hselasky > Date: Mon Aug 6 08:40:02 2018 > New Revision: 337374 > URL: https://svnweb.freebsd.org/changeset/base/337374 > > Log: > Implement atomic_long_cmpxchg() function in the LinuxKPI. > > Submitted by: Johannes Lundberg > MFC after: 1 week > Sponsored by: Mellanox Technologies > > Modified: > head/sys/compat/linuxkpi/common/include/asm/atomic-long.h > > Modified: head/sys/compat/linuxkpi/common/include/asm/atomic-long.h > > ============================================================================== > --- head/sys/compat/linuxkpi/common/include/asm/atomic-long.h Mon Aug 6 > 08:35:16 2018 (r337373) > +++ head/sys/compat/linuxkpi/common/include/asm/atomic-long.h Mon Aug 6 > 08:40:02 2018 (r337374) > @@ -81,6 +81,21 @@ atomic_long_xchg(atomic_long_t *v, long val) > return atomic_swap_long(&v->counter, val); > } > > +static inline long > +atomic_long_cmpxchg(atomic_long_t *v, long old, long new) > +{ > + long ret = old; > + > + for (;;) { > + if (atomic_cmpset_long(&v->counter, old, new)) > + break; > + ret = READ_ONCE(v->counter); > + if (ret != old) > + break; > + } > + return (ret); > +} This code is seriously inferior to atomic_fcmpset_long, which happens to return the found value just like the linux atomic_long_cmpxchg would. The atomic_cmpset_* primitives should not be used if the target value is to be inspected. + > static inline int > atomic_long_add_unless(atomic_long_t *v, long a, long u) > { > > -- Mateusz Guzik