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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 52A83C021B8 for ; Tue, 4 Mar 2025 15:39:19 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id DC2D26B0085; Tue, 4 Mar 2025 10:39:18 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id D72496B0089; Tue, 4 Mar 2025 10:39:18 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C616A6B008A; Tue, 4 Mar 2025 10:39:18 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id A8F3A6B0085 for ; Tue, 4 Mar 2025 10:39:18 -0500 (EST) Received: from smtpin10.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 3B1E3120254 for ; Tue, 4 Mar 2025 15:39:18 +0000 (UTC) X-FDA: 83184277596.10.52C98BF Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf26.hostedemail.com (Postfix) with ESMTP id 2D084140010 for ; Tue, 4 Mar 2025 15:39:05 +0000 (UTC) Authentication-Results: imf26.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf26.hostedemail.com: domain of "SRS0=XP9Z=VX=goodmis.org=rostedt@kernel.org" designates 139.178.84.217 as permitted sender) smtp.mailfrom="SRS0=XP9Z=VX=goodmis.org=rostedt@kernel.org" ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1741102745; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=IE/KA7tEe2K+Nzsj5q2/MnbWLcvDlsRGtHx8bCKwOkU=; b=1VY6RzrMG6NnyyNAB6XwPdaMwQY68t7eHX0B7ulBrr9BOCbAK+keE9vv3NiyX4NjkOql4c QpM+sNWPotHqpxpzArP3fCBzLrl/2l6RJDx9vOjTzutT2s0PjffxEGr4Fyl2mZgXL1FBfU Qqo4BI6KrPXnySuFb91D2fV2dN4TK1U= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1741102745; a=rsa-sha256; cv=none; b=AJOUbjXuZM3OkTUsSu1uWLXxC5tp09iFTmiAoVAMDGxwDXNh47B04vqd8uvMkYdeEIYei7 1QMZ6+ihtvYfO4yEFSJBFoU6nbb9g1c/o1ZDICAmMpY/kJeYJVKGfwtWpsrTgYEX5jC4k2 +62jSlbgH0suwAhzR+96D2VQpXJRMdQ= ARC-Authentication-Results: i=1; imf26.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf26.hostedemail.com: domain of "SRS0=XP9Z=VX=goodmis.org=rostedt@kernel.org" designates 139.178.84.217 as permitted sender) smtp.mailfrom="SRS0=XP9Z=VX=goodmis.org=rostedt@kernel.org" Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 6CD8E5C4823; Tue, 4 Mar 2025 15:36:47 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B0796C4CEE7; Tue, 4 Mar 2025 15:39:02 +0000 (UTC) Date: Tue, 4 Mar 2025 10:39:57 -0500 From: Steven Rostedt To: Tang Yizhou Cc: tj@kernel.org, jack@suse.cz, brauner@kernel.org, willy@infradead.org, akpm@linux-foundation.org, mhiramat@kernel.org, ast@kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/3] writeback: Let trace_balance_dirty_pages() take struct dtc as parameter Message-ID: <20250304103957.08c79da0@gandalf.local.home> In-Reply-To: <20250304110318.159567-2-yizhou.tang@shopee.com> References: <20250304110318.159567-1-yizhou.tang@shopee.com> <20250304110318.159567-2-yizhou.tang@shopee.com> X-Mailer: Claws Mail 3.20.0git84 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam02 X-Stat-Signature: 3tsgyg7z7g8aao13cppwkkdt75kj3tfz X-Rspamd-Queue-Id: 2D084140010 X-Rspam-User: X-HE-Tag: 1741102745-775700 X-HE-Meta: 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 2rQs/Grg GczNx036vTNEUYGZzJy789iANAawumw19V/OPYhiqqE6M5ZCnt/HyaRp817mLjAizGo8bSoZs4ZkHJfbehuthE3Szu4L6kdFthbKGdy5gWlRYkyd3d21ACv96M/L3cxDy6B3ZsMmzOTVpmxG7EkCTKJWfuAxdNwY7ejNBLD+8P2FVVCLCWmWpsN2BA2meDlXKhbiRAhz2Rnxy+bP1S7AvbI2StbhMeKjfyHLY6Kv0XIGNELh4tIgJprhfu+EHnFNfEWxvyKKZLKMj6eKMwsjhYgtw3sT8DwlR+JhKf9CgLrzCBonYtn68qweTObZADouVicRtdJJMAqxBxFWZUsZPRxZHNt+F9utOAbUs X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, 4 Mar 2025 19:03:16 +0800 Tang Yizhou wrote: > @@ -664,16 +660,16 @@ TRACE_EVENT(balance_dirty_pages, > ), > > TP_fast_assign( > - unsigned long freerun = (thresh + bg_thresh) / 2; > + unsigned long freerun = (dtc->thresh + dtc->bg_thresh) / 2; > strscpy_pad(__entry->bdi, bdi_dev_name(wb->bdi), 32); > > __entry->limit = global_wb_domain.dirty_limit; > __entry->setpoint = (global_wb_domain.dirty_limit + > freerun) / 2; > - __entry->dirty = dirty; > + __entry->dirty = dtc->dirty; > __entry->bdi_setpoint = __entry->setpoint * > - bdi_thresh / (thresh + 1); > - __entry->bdi_dirty = bdi_dirty; > + dtc->wb_thresh / (dtc->thresh + 1); > + __entry->bdi_dirty = dtc->wb_dirty; > __entry->dirty_ratelimit = KBps(dirty_ratelimit); > __entry->task_ratelimit = KBps(task_ratelimit); > __entry->dirtied = dirtied; I don't know how much of a fast path these tracepoints are in, but instead of doing the divisions above, why not just save the values in the ring buffer, and do the divisions in the TP_printk() section, which is done when the user reads it and not when the code is executing? -- Steve