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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 58B7FC64EC4 for ; Fri, 10 Mar 2023 16:59:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231796AbjCJQ73 (ORCPT ); Fri, 10 Mar 2023 11:59:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56600 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231690AbjCJQ7G (ORCPT ); Fri, 10 Mar 2023 11:59:06 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D9A8A1F4B2 for ; Fri, 10 Mar 2023 08:56:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1678467400; 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=MEXbWR4Mui1qGAf1N0KRjooVxPuGH4qpgY7EflKN58I=; b=ecFrTRVXnOPlT49qJra/W9i0tQW4skGcX0FcRBbADkmc826VfCM+fioaZGzBWqbwAD0G9J ow+sM8BU5tTvCa/tHp1UIsj+e/aCXo05eUbT9WUPzczzgtOO2yLTqZur1NKUtAxylRByQ4 g0pCJ2tNmkYKNCypHnVBSwyfNsLWIm8= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-478-fluu-AfhOnGFHF-1KlcnRQ-1; Fri, 10 Mar 2023 11:56:36 -0500 X-MC-Unique: fluu-AfhOnGFHF-1KlcnRQ-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 372F43C0E463; Fri, 10 Mar 2023 16:56:36 +0000 (UTC) Received: from localhost (unknown [10.39.192.17]) by smtp.corp.redhat.com (Postfix) with ESMTP id A1BE2C15BA0; Fri, 10 Mar 2023 16:56:30 +0000 (UTC) Date: Fri, 10 Mar 2023 11:56:28 -0500 From: Stefan Hajnoczi To: Ming Lei Cc: Jens Axboe , io-uring@vger.kernel.org Subject: Re: Resizing io_uring SQ/CQ? Message-ID: <20230310165628.GA491749@fedora> References: <20230309134808.GA374376@fedora> <2f928d56-a2ff-39ef-f7ae-b6cc1da4fc42@kernel.dk> <20230310134400.GB464073@fedora> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="51HGqewKny2lCSCR" Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org --51HGqewKny2lCSCR Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Fri, Mar 10, 2023 at 11:14:04PM +0800, Ming Lei wrote: Hi Ming, Another question about this: Does the io worker thread pool have limits so that eventually work queues up and new work is not able to execute until in-flight work completes? In that case, even if io_uring_enter(2) accepts requests without returning EBUSY/EAGAIN, it seems like there is still a deadlock scenario when work that is executing depends on later work that is unable to execute. Stefan --51HGqewKny2lCSCR Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAmQLYTwACgkQnKSrs4Gr c8gG6AgAu87F3b5QYS13JNKxh8pAPJxLQ3iahYPtWjhN+y73YUqTrqRgFeo3hl0T 0AtKuv6fupkgJ3tVVyU4D4nS9eeHs12D4A77zkWu6lBUcueWOW7iQyN0iRvgqUfp axPfuCKtHmXF5NGajANSJgZr9+YB2+fvKGNkN4nrMDNzrL+QLj75ZgvcXHRTDmW/ awfDpwwmYXHW48oUbAevlZn3qcEfxTJPmf5+r/HFaG3EpyNdcI2ZnR6Shd7Y8Y8u VN4hwGADBfk8f9yUSC4oDJ49qRbv7N9WZjZJKGBZPuVz6MzrL40WR9fY2cKVEDkV fQ2vJMq9UnyHvqfc/r8qUS6cTB+F0A== =7T95 -----END PGP SIGNATURE----- --51HGqewKny2lCSCR--