From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CF5FE3AFD15; Tue, 1 Sep 2026 07:17:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788247074; cv=none; b=kRmHRHmTd8DGfiDG65yR5yYVlUnq3a3m8qo/7v4GxlDxRNa6i1WPZOwk53tFKPw0rSJ/Rc+HXKV8nxglIaoLy/DIVbxgxszeCncraL5OP0FIINDm/xHGCdcGQRa+nDOx7c2O+niHe2NxXvAv4d+XXsG4U6CKX/3tfSucRGEHkfI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788247074; c=relaxed/simple; bh=aYsR4jlSpvw+sq28AnmN4VK19KR2u8+yQgAudjkCgwo=; h=From:To:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=mZVoRez4D5terAh3nt32BimhcfcR4a/Zn+SLrKvXevAIjFhYy2I4ZI8sfcerSO66+qZBYByQbNbAqJvWcDDRW/eNxthhhqVnFkGdZphbIy5s5r/c+8VnE/YBNtNawaUNiH43PBpsiF/fkIryx+TL+NHmDA6xYlkLTo0swUHIW50= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=nXIUXcWZ; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=dkxWMDP3; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="nXIUXcWZ"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="dkxWMDP3" From: Nam Cao DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1788247065; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=aYsR4jlSpvw+sq28AnmN4VK19KR2u8+yQgAudjkCgwo=; b=nXIUXcWZjolppAHh1zVBFoGC4q7dKaxM7h0uTDRleQGSkMsfafrcOyjXjJTWxf+duJLn+F 8M3YpGLBV5DzLZC5cCbhCUxy5eM0SopO0HbpQZ54pfPBMeLNn70C3FQnjE5nXq3mUh3e3a tug8lZ9heCOE9ttdhE3dVVBgyY3ZTXIGS1RqEsR1waclzyNz80S5bdey2CKqATseTZgct8 /aTo+tON01enbkNyayXb3cvUF+OP+91NTVnmj7jCVbD/F4nOWe5kVa0WWyAPTZJaZo2ZOf mg2nlmlegYvMNFm05ow6+GmA8Kzg37o6CGKzAuPEkOuNUfOGpt1lmtYTeAho9w== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1788247065; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=aYsR4jlSpvw+sq28AnmN4VK19KR2u8+yQgAudjkCgwo=; b=dkxWMDP39RG56vHjE/4FJvlxmSp/dQgpWXMdl2ECQU462YD9FgCiSDQApwRYCODsdsRJnE oDZlWd+faRK+TgAw== To: Kuniyuki Iwashima , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rt-devel@lists.linux.dev Subject: Re: [PATCH net-next v4 0/1] af_unix: Fix priority inversion issue In-Reply-To: References: Date: Tue, 01 Sep 2026 09:17:44 +0200 Message-ID: <871pbdbftz.fsf@yellow.woof> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Hi, Nam Cao writes: > While auditing AF_UNIX sockets, I noticed that the sendmsg() code paths may > block on the garbage collector running as workqueue. This can cause > priority inversion and latency for real-time users. > > The implementation does kindly avoid blocking "sane users". However, it is > impossible to tell whether the kernel's definition of "sane users" > accurately describes all users out there. > > Digging into history and figuring out the reasons why sendmsg() needs to > wait for garbage collector, it is determined that those reasons no longer > apply. I just looked at patchwork and noticed that this patch is marked as "Changes Requested", but I'm not sure what changes are still expected. Did I miss a question or an issue that still needs to be addressed? Nam