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=-2.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 64C0BC43460 for ; Tue, 27 Apr 2021 03:30:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4515E613A9 for ; Tue, 27 Apr 2021 03:30:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234447AbhD0DbG (ORCPT ); Mon, 26 Apr 2021 23:31:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50272 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234371AbhD0Day (ORCPT ); Mon, 26 Apr 2021 23:30:54 -0400 Received: from mail-lf1-x134.google.com (mail-lf1-x134.google.com [IPv6:2a00:1450:4864:20::134]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EF160C06175F for ; Mon, 26 Apr 2021 20:30:10 -0700 (PDT) Received: by mail-lf1-x134.google.com with SMTP id x19so61136985lfa.2 for ; Mon, 26 Apr 2021 20:30:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=1/f4JVixSDUtfY05Md2NUGmbhN57QIb2bgma7dK5cAU=; b=Haegntx8II71fsjo5ukch+sUDr23zEkF/J/qNEpVmmL/ZqvcJAgbctNfGpJt84CeSZ s+F+HfGj+q1ifZqOPXfc+7VWk5hLwGqnU8juAJQQfH+Xn5SKE0vNWjJdFF5F1QR2Q/w1 OyfyMhebqHwHBl5HlBwQEW7CiLECAp9E8DHt1Hzwf0Lo/swVjRdh/XAcGcADCZfF+nsq PIbUmWmumb6wh3R4L9iBUBN63IqsRpM/GOmJWWH/YmHgpdzE9nYmZXpAvI4IEc2ps2UZ 94b2pzL49zWIfq5Mtd9HSyL7gDz9sBK3YyJjVSkvX4lFchmQ3JmTgAHc3iFQnYcWeSE7 6rKg== 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=1/f4JVixSDUtfY05Md2NUGmbhN57QIb2bgma7dK5cAU=; b=ahHU5M+uPotS2DinoYP5NY9bJ5O0OlrPGKox9rMUPpUi+JKiqTpWiDh09GgdAKYbLG C/JzIsmnYQvGQ/xIfcvPrtF81MqDcVmpddmtaKq/X0tvTevvPUGW2Tqn7rt+DJbY26tz bCOLaqh9r+XO/IrHvkVZYNURyQaG4n68EFyJrRwSCYVlcKeo87x4tXbmrKJ/gu93mten M1kOaq5gDtI5k0VbxDx2R0LWaNjegH2hGS3fnZEB3PWpUYCkKtIq4+v2orSvFDqeeOwb l1bTHy4Pn1gVVP+IlGtz30MQuHEXoSUZGhwaVCOyH50EisWpygCfWoZariBX32sFHOwR kCzQ== X-Gm-Message-State: AOAM5331HDOqiSQqPoe62morwKCBTaG+IEOYNJF+XcBb0nz4wpPv/wgo +hPGZE7zPWLLL7VWwiiN9Q9gquQJy4f0Km8YnlKA8SJn24DVMw== X-Google-Smtp-Source: ABdhPJwb20u/69HZE27J3wrxf12je+L3qCbCg+Zfj/Sb+4NGCjbGt7tjCcSB/OyfAvpYJdy0V+aO3Y7OdXWGS7TK7Xo= X-Received: by 2002:a19:f504:: with SMTP id j4mr2105098lfb.307.1619494208480; Mon, 26 Apr 2021 20:30:08 -0700 (PDT) MIME-Version: 1.0 References: <1619491400-1904-1-git-send-email-sxwjean@me.com> <20210427025358.GV235567@casper.infradead.org> In-Reply-To: <20210427025358.GV235567@casper.infradead.org> From: Xiongwei Song Date: Tue, 27 Apr 2021 11:29:32 +0800 Message-ID: Subject: Re: [PATCH] mm: append __GFP_COMP flag for trace_malloc To: Matthew Wilcox Cc: Xiongwei Song , cl@linux.com, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org, vbabka@suse.cz, linux-mm@kvack.org, Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 27, 2021 at 10:54 AM Matthew Wilcox wrote: > > On Tue, Apr 27, 2021 at 10:43:20AM +0800, Xiongwei Song wrote: > > From: Xiongwei Song > > > > When calling kmalloc_order, the flags should include __GFP_COMP here, > > so that trace_malloc can trace the precise flags. > > I suppose that depends on your point of view. Correct. Should we report the > flags used by the caller, or the flags that we used to allocate memory? > And why does it matter? When I capture kmem:kmalloc events on my env with perf: (perf record -p my_pid -e kmem:kmalloc) I got the result below: 0.08% call_site=ffffffff851d0cb0 ptr=0xffff8c04a4ca0000 bytes_req=10176 bytes_alloc=16384 gfp_flags=GFP_ATOMIC|__GFP_NOWARN|__GFP_NOMEMALLOC 0.08% call_site=ffffffff851d0cb0 ptr=0xffff8c04a4ca4000 bytes_req=10176 bytes_alloc=16384 gfp_flags=GFP_ATOMIC|__GFP_NOWARN|__GFP_NOMEMALLOC 0.08% call_site=ffffffff851d0cb0 ptr=0xffff8c04a4ca8000 bytes_req=10176 bytes_alloc=16384 gfp_flags=GFP_ATOMIC|__GFP_NOWARN|__GFP_NOMEMALLOC 0.08% call_site=ffffffff851d0cb0 ptr=0xffff8c04a6f80000 bytes_req=10176 bytes_alloc=16384 gfp_flags=GFP_ATOMIC|__GFP_NOWARN|__GFP_NOMEMALLOC 0.08% call_site=ffffffff851d0cb0 ptr=0xffff8c04a6f84000 bytes_req=10176 bytes_alloc=16384 gfp_flags=GFP_ATOMIC|__GFP_NOWARN|__GFP_NOMEMALLOC 0.08% call_site=ffffffff851d0cb0 ptr=0xffff8c04a6f88000 bytes_req=10176 bytes_alloc=16384 gfp_flags=GFP_ATOMIC|__GFP_NOWARN|__GFP_NOMEMALLOC 0.08% call_site=ffffffff851d0cb0 ptr=0xffff8c04a6f8c000 bytes_req=10176 bytes_alloc=16384 gfp_flags=GFP_ATOMIC|__GFP_NOWARN|__GFP_NOMEMALLOC 0.07% call_site=ffffffff851d0cb0 ptr=0xffff8c04a4c80000 bytes_req=10176 bytes_alloc=16384 gfp_flags=GFP_ATOMIC|__GFP_NOWARN|__GFP_NOMEMALLOC The value of gfp_flags made me confused, I spent some time to find out which trace_malloc is here. So I think we should append __GFP_COMP. Regards