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 418F8C433EF for ; Sat, 15 Jan 2022 08:28:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231462AbiAOI2j (ORCPT ); Sat, 15 Jan 2022 03:28:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37318 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230260AbiAOI2j (ORCPT ); Sat, 15 Jan 2022 03:28:39 -0500 Received: from mail-pf1-x42d.google.com (mail-pf1-x42d.google.com [IPv6:2607:f8b0:4864:20::42d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E7899C061574; Sat, 15 Jan 2022 00:28:38 -0800 (PST) Received: by mail-pf1-x42d.google.com with SMTP id i17so4923120pfk.11; Sat, 15 Jan 2022 00:28:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=efWehKZqRZyT3jLnEWgoS2SgOYAw1yEu1mXqwwUFMx0=; b=H74tADmE6ZvkeEHIAbwLaQ8zX5/lgfrN7ZV2mHIRWdDkDdxZQwCpjfhz0+AYkDeHYd OZByOV1UkTnHtR+zGkphNvPgwHdQcN12krpLbTpxmCT8djRqULTofnU9GJioE4uoutPP FQal7N2TNujqY7DuWNuTSvOnyNUbd+WILPoGOqC2yvA8Z5Gv2FhHnd+hjC1GJkjRqH7a 5RA+mN87WNBNNYNbwAe6YKSZA40lpnxi6+xNJnTla7V69GRmYC7qTcXG7lYvfT1P6L+o iyQ0Xc1CmzktK0Tvdgk9sX/SLaikAv0PBPQEgYf0t7HwPnrI48ytt1SeA4KXqe8Ket3k TgAw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=efWehKZqRZyT3jLnEWgoS2SgOYAw1yEu1mXqwwUFMx0=; b=DT1kKx7gtO36VzZq0q4s5t8W/Hv8onqLYp8Kko15TYHxT2ws1DAyLWF9iiqD9wfVKr UxIHL+tojLo7xRmLTE1wBXPu70V93vvWCN/Te+O4M/1EufcMRgcb54PqNiono/72RSw5 kfkrlZimK7yo3G+JG6vpPNrcdERWFvvjToiBZGkN4epsc61kVfxmrfZ1j0X6lTA5ttzO wiATIwI+dyAuKRzDZAQ8r49N2ynxw/RXhcyIbcSZtrzS9FEqnHo9eHKS1G0bZoIF83xe eU9dyGkDUralH9wzg92rIH7ya57Go/vYyNjkL9eBrxcmtB3PecC4zct5mlsvm+hj5Pmy 18OQ== X-Gm-Message-State: AOAM533+D26ypv+o4I5ghvZHZL0FFSL9RuC06fevVie46gBnhUuH2SIr khQSVaAe+IcpB2IYGw0tqJs= X-Google-Smtp-Source: ABdhPJzR7Ih/JG4YJEC3irQPMeanjUipcGm7OZiNQoSEEayTkcAcCCV0Tq/6nM6XaAlpwtoj6M8mkQ== X-Received: by 2002:a63:eb07:: with SMTP id t7mr11147967pgh.112.1642235318501; Sat, 15 Jan 2022 00:28:38 -0800 (PST) Received: from archlinux.localdomain ([140.121.198.213]) by smtp.gmail.com with ESMTPSA id i63sm673577pfg.20.2022.01.15.00.28.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 15 Jan 2022 00:28:38 -0800 (PST) From: Huichun Feng To: guro@fb.com Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, mgorman@techsingularity.net, mingo@redhat.com, peterz@infradead.org Subject: Re: [PATCH rfc 0/6] Scheduler BPF Date: Sat, 15 Jan 2022 16:29:24 +0800 Message-Id: <20220115082924.4123401-1-foxhoundsk.tw@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20210916162451.709260-1-guro@fb.com> References: <20210916162451.709260-1-guro@fb.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Hi Roman and the list, I have a naive question regarding BPF hook for sched. Given that BPF can also be attached to tracepoint, why do we add a BPF prog type specific to sched? The reason I can come up with is that sched BPF can have retval to drive the scheduling decision in static branch, whereas tracepoint is not able to do this. Is it mainly because of this or anything else? Thanks Huichun