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 X-Spam-Level: X-Spam-Status: No, score=-0.7 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EA44DC3A5A0 for ; Mon, 19 Aug 2019 15:09:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B98D520651 for ; Mon, 19 Aug 2019 15:09:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=brainfault-org.20150623.gappssmtp.com header.i=@brainfault-org.20150623.gappssmtp.com header.b="TjRfrMeu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727748AbfHSPJR (ORCPT ); Mon, 19 Aug 2019 11:09:17 -0400 Received: from mail-wr1-f65.google.com ([209.85.221.65]:44841 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726343AbfHSPJR (ORCPT ); Mon, 19 Aug 2019 11:09:17 -0400 Received: by mail-wr1-f65.google.com with SMTP id p17so9080063wrf.11 for ; Mon, 19 Aug 2019 08:09:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=brainfault-org.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=cexPhrCLObLWuEp73k9kJmodhWBwZ7DxuWqGj7qCEDA=; b=TjRfrMeuPlMjyuBy47+ksxr6FmfZjGkDNkXRu5/hwIyw1NlgdUHHn6o94/O+Wxoy0P OqwTYfWZU/kaEZ3NBy27JlqV6AOJzjmTIHTMx3qvNywoNOSAR7soXBUJa5uWbx++pmp1 3urb9mti67/zJHeHCkgNfCPslQ33U0Yxz9huifekewmAjgfpkr3F82NhvOL4ZhMGnEup Uo+SMvSwQfu3EbtKP+U2QsI+msI4BgSDPcNE4WSRq6hHfBpaaLjzEiodzpm0sJCxTh9v N8FWjUPivsUUEZh7nB4NhK/aK25uEEhTFjPDjhYukNG2PjXrO3UyR795lTmkZxJe6/gU SqOw== 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=cexPhrCLObLWuEp73k9kJmodhWBwZ7DxuWqGj7qCEDA=; b=m37figKbyFApTFvN6392RmJEdb03j1YyXQ/BYmhAdVl/ME2TSfMl7ULJELalZylvLw DWw1zxN2jCzenKq1EW4EOKeUqwPx6DWjWhZ8aC7w+EAuQRa1/qyS4Vc7y7rdDZ1FODL1 RQ7GA35gC0mDv0sqdl11OcsKPDMJmmJpdmhU1tLhLSWTPWCpZIQ4fACsXBAvreXOkwlm J5BplPyOndYqxAYF4q/IM21jkPCXW01KDXduq2NfTeoeOa/0ABaPTIFeGILvcWr/MIx8 RqL8VZX8d8DKqUL8LpZpj1XwsgakHpjHhf+0/Qx9gBRvIp9zU4SY8VU7arP0p9E9yuy8 0bFw== X-Gm-Message-State: APjAAAX/+fHobu1VUlV7LJg6Myagwn+hPSdgtnQfYii7k3f67akJ52CU Ok8VMQCBlzPw2v/iMxltLO/eOHUM4hJ4/QPkil/zPQ== X-Google-Smtp-Source: APXvYqxV/0uOhnuxnc2R0h3qP1aT0Liq9FhY/9Gz4IWrfKiJ3gPJFTzL/OOJpQPukmL9s4TFqlCHy2g9K4TSCe3fKcE= X-Received: by 2002:a05:6000:104c:: with SMTP id c12mr25030881wrx.328.1566227354761; Mon, 19 Aug 2019 08:09:14 -0700 (PDT) MIME-Version: 1.0 References: <20190810014309.20838-1-atish.patra@wdc.com> <20190812145631.GC26897@infradead.org> <20190813143027.GA31668@infradead.org> <3f55d5878044129a3cbb72b13b712e9a1c218dc7.camel@wdc.com> <20190819144627.GA27061@infradead.org> In-Reply-To: <20190819144627.GA27061@infradead.org> From: Anup Patel Date: Mon, 19 Aug 2019 20:39:02 +0530 Message-ID: Subject: Re: [PATCH] RISC-V: Issue a local tlb flush if possible. To: "hch@infradead.org" Cc: Atish Patra , "aou@eecs.berkeley.edu" , "gregkh@linuxfoundation.org" , Anup Patel , "linux-kernel@vger.kernel.org" , "alexios.zavras@intel.com" , "palmer@sifive.com" , "paul.walmsley@sifive.com" , "linux-riscv@lists.infradead.org" , "allison@lohutok.net" Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 19, 2019 at 8:16 PM hch@infradead.org wrote: > > On Thu, Aug 15, 2019 at 08:37:04PM +0000, Atish Patra wrote: > > We get ton of them. Here is the stack dump. > > Looks like we might not need to flush anything at all here as the > mm_struct was never scheduled to run on any cpu? If we were using ASID then yes we don't need to flush anything but currently we don't use ASID due to lack of HW support and HW can certainly do speculatively page table walks so flushing local TLB when MM mask is empty might help. This just my theory and we need to stress test more. Regards, Anup