From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 38C873A543F for ; Thu, 30 Jul 2026 18:55:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785437759; cv=none; b=JgT3PLzku+CvvT27QRu3oK8D0TIOeQQfE5SQNpfM885IybHBsZpuvvU0WSxOWzxHQnftdj1G65gcPmyjL7o8OkmPyOBDJ9m7poT8fY5M+91IFokHfN1g8inAGAqAxZenG225d4EubqA0fknKEBsG9Hm3SLrYhhbqVdUhXbL6kMg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785437759; c=relaxed/simple; bh=dl1rKl8N+PfRnV2OM93Q8FD6tKPbkYfGbZqm8os4mK0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=OFAQVUI2woe3SUbQShGF4BoG5PHR3zTKQd9U1uGrHPEdRyteXsb32004Nxu7cNJ8nGk3PT/pIYdWgVvlU2eBDNfCRkwi20Ulh7zjRsdJYKGsr8OV+ihCzz+9qBkury/0P5d+S7tAkr5/0X/q2pAXcRCFSEtYzonIKhe5Tcr4ihs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=ZHJzLPIO; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="ZHJzLPIO" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1785437757; 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=dl1rKl8N+PfRnV2OM93Q8FD6tKPbkYfGbZqm8os4mK0=; b=ZHJzLPIOZhadQ6tp7HsVWjf6bL0qe9A4tQgnTe0DQOAsvsKOsAdgHHDC4NBubAVkUieRva FXsmUdahDvkQ1TpfSbPo5O8vdxaun1OAu7Z7HaAm8jwbWF9gSwfPZT3AOYpLAwN72j8ZYC a7pQSXTRVz28BWAh6zf3teoKQ5ddvbM= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-265-31ZFZ1xBNoaWe5ptHafRVQ-1; Thu, 30 Jul 2026 14:55:51 -0400 X-MC-Unique: 31ZFZ1xBNoaWe5ptHafRVQ-1 X-Mimecast-MFC-AGG-ID: 31ZFZ1xBNoaWe5ptHafRVQ_1785437749 Received: from mx-prod-int-10.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-10.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.95]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 397C2195608E; Thu, 30 Jul 2026 18:55:48 +0000 (UTC) Received: from fedora (unknown [10.44.33.21]) by mx-prod-int-10.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id 60299423; Thu, 30 Jul 2026 18:55:42 +0000 (UTC) Received: by fedora (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Thu, 30 Jul 2026 20:55:47 +0200 (CEST) Date: Thu, 30 Jul 2026 20:55:41 +0200 From: Oleg Nesterov To: Linus Torvalds Cc: Breno Leitao , Christian Brauner , Mateusz Guzik , Jens Axboe , Pavel Begunkov , Alexander Viro , Jan Kara , Alexey Gladkov , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, io-uring@vger.kernel.org Subject: Re: [PATCH v3 0/1] pipe: only enable the extra wake_up(rd_wait) for edge-triggered consumers Message-ID: References: Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 3.6 on 10.30.177.95 On 07/30, Linus Torvalds wrote: > > I like this patch mostly for the renaming, not because I think it > matters. I think "poll usage" was a mistake in naming and doesn't > explain the issue. That said, I'd go even further, and make it clear > that it's not about "poll" itself - which is fine, it's about "epoll", > which has that broken crazy bug where it calls something "edge > triggered" but then actually wants effectively level-triggered > behavior - wakeups when nothing actually changed, which is the > *opposite* of an edge. I am not sure this is a "crazy bug". To me, epoll with EPOLLET works "as documented". Perhaps I am wrong, this predates the git history. I'd say the very idea of EPOLLET was wrong, but this doesn't matter: we have what we have. And this patch (mostly) tries to document what we have. > Pure garbage. > > So the real name should be something like "epoll_pseudo_edgetrigger". > Because "et" isn't really helpful either. I'd agree with "pseudo" simply because I can hardly say how could we define "edgetrigger" in this particular case. But then we should name it "epoll_or_io_uring_pseudo_edgetrigger". See the test-cases, they demonstrate the same pattern. Oleg.