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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 BB0DAC43331 for ; Thu, 26 Mar 2020 14:31:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8E8AB20787 for ; Thu, 26 Mar 2020 14:31:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=cmpxchg-org.20150623.gappssmtp.com header.i=@cmpxchg-org.20150623.gappssmtp.com header.b="qoWgKMmx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727975AbgCZObG (ORCPT ); Thu, 26 Mar 2020 10:31:06 -0400 Received: from mail-qk1-f195.google.com ([209.85.222.195]:37185 "EHLO mail-qk1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727652AbgCZObG (ORCPT ); Thu, 26 Mar 2020 10:31:06 -0400 Received: by mail-qk1-f195.google.com with SMTP id x3so6592191qki.4 for ; Thu, 26 Mar 2020 07:31:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=OG09KzA4HuO3BOZQKOUcZGEc5bHon2VHvRmMFTk+/XA=; b=qoWgKMmxmpHam08hoCe/t+7K2pObYsUEj4WceDC2aYtZWU8vi2g/tN8slLtc3BxjBQ pGuuz/h4e4WdyEA4STkS2V20DKT0odYewLHs/KD6Swj+Hjz0EopvGoPjguT9OiHImxgz JSNQ4UfzFQLnDG8g0kaJ5JiI+DQgHfZDhV/C+QIVkyHBN6j/fCiN8tQFb1Gn0RXjPl/s p1XAl2850NR2WnH+fot1vcN8DkLnIB+aYxYnPX3B9cFQ4/gwFx4nH2GYGeguWFdMTR17 yhUPE6GdTz0DDJly8bhRXzbabDbpiPZ9fctxKFzaD0nWYgvZ8wshtAgHBcC/gFOmLc3k wXPw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=OG09KzA4HuO3BOZQKOUcZGEc5bHon2VHvRmMFTk+/XA=; b=m23IkhaVxxbMKWVac2AOz8qae3MOcXM7UsRT7BF7bkeJJrGGQMjgkGifA+9HBTaoT4 NyoIGMUvhw6kOLfCseI58v1pZ+e/WYhFl0n/M6Kr3NVGWcs/0sXOR4wFJO1recnxAy1d Nb5kX2SVp2DbcUy34+07kEVcyh6s6Z/kZAYnL5nd+2bSDyNPUqzY3C8Lx3rxWcTPEf5m 2EANXesPwHEzjpH+GyPuOkZF78Dr/6WDhTUKW0h8Kkcbgz9oT7hAf4yZfw2C7eZqPljz t85n+g3o/2n198UVq9ICEAp+a0WmMN2ExORW8SXvM5/8JGWu4g+DZViXlKeo4TD2671t c+Lg== X-Gm-Message-State: ANhLgQ2az/tb2uzAfW44xNj8AkVaRaU0JrmN+5IlhXcrA8dy55yjMQVY wRwj4tWoj17NqkeVZMcEeXsXsQOwloM= X-Google-Smtp-Source: ADFU+vvGmFJhahNS012z36bU++nM6aRvUkvuLENBAKAt9FwVnPCjAaq50NPPkVV/ZfywFdTOJpV6LA== X-Received: by 2002:a05:620a:529:: with SMTP id h9mr8463342qkh.142.1585233065063; Thu, 26 Mar 2020 07:31:05 -0700 (PDT) Received: from localhost ([2620:10d:c091:480::1:a9a9]) by smtp.gmail.com with ESMTPSA id l60sm1700051qtd.35.2020.03.26.07.31.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 26 Mar 2020 07:31:04 -0700 (PDT) Date: Thu, 26 Mar 2020 10:31:02 -0400 From: Johannes Weiner To: Yafang Shao Cc: peterz@infradead.org, akpm@linux-foundation.org, mhocko@kernel.org, axboe@kernel.dk, mgorman@suse.de, rostedt@goodmis.org, mingo@redhat.com, linux-mm@kvack.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/2] psi: enhance psi with the help of ebpf Message-ID: <20200326143102.GB342070@cmpxchg.org> References: <1585221127-11458-1-git-send-email-laoar.shao@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1585221127-11458-1-git-send-email-laoar.shao@gmail.com> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Thu, Mar 26, 2020 at 07:12:05AM -0400, Yafang Shao wrote: > PSI gives us a powerful way to anaylze memory pressure issue, but we can > make it more powerful with the help of tracepoint, kprobe, ebpf and etc. > Especially with ebpf we can flexiblely get more details of the memory > pressure. > > In orderc to achieve this goal, a new parameter is added into > psi_memstall_{enter, leave}, which indicates the specific type of a > memstall. There're totally ten memstalls by now, > MEMSTALL_KSWAPD > MEMSTALL_RECLAIM_DIRECT > MEMSTALL_RECLAIM_MEMCG > MEMSTALL_RECLAIM_HIGH > MEMSTALL_KCOMPACTD > MEMSTALL_COMPACT > MEMSTALL_WORKINGSET_REFAULT > MEMSTALL_WORKINGSET_THRASHING > MEMSTALL_MEMDELAY > MEMSTALL_SWAPIO What does this provide over the events tracked in /proc/vmstats? Can you elaborate a bit how you are using this information? It's not quite clear to me from the example in patch #2.