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 D78F9C47258 for ; Fri, 26 Jan 2024 03:12:46 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0ADED6B0074; Thu, 25 Jan 2024 22:12:46 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 0365D6B0075; Thu, 25 Jan 2024 22:12:45 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E68606B0078; Thu, 25 Jan 2024 22:12:45 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id D62C36B0074 for ; Thu, 25 Jan 2024 22:12:45 -0500 (EST) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id B5F99A250B for ; Fri, 26 Jan 2024 03:12:45 +0000 (UTC) X-FDA: 81719989890.08.D8C5334 Received: from mail-pf1-f180.google.com (mail-pf1-f180.google.com [209.85.210.180]) by imf17.hostedemail.com (Postfix) with ESMTP id DE0D740009 for ; Fri, 26 Jan 2024 03:12:43 +0000 (UTC) Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=chromium.org header.s=google header.b=n222AtNN; spf=pass (imf17.hostedemail.com: domain of senozhatsky@chromium.org designates 209.85.210.180 as permitted sender) smtp.mailfrom=senozhatsky@chromium.org; dmarc=pass (policy=none) header.from=chromium.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1706238764; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=lBA+mhnxqJOP4m7joWy+QwgY4c+lF7vio24SpkEJ2hc=; b=3E+rUvJcNZJgodHvDcWEgHw5eVu1cJ8Ht2HQnktCU/eF/xKIZI0M4KNyweS0CXH9mCLGZC AYg6IzF7ijliOCZGaeccRd3EVw4jrjT4jOM9fyrm1+JzwXbpuiA7bZLcn3FlPSXpwYlPAP zqr9TTddsNXUaOE8T3Z9RnVgmXpnfIA= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1706238764; a=rsa-sha256; cv=none; b=f4LJqIysafb+iegRJEtPr69olUyWQvjFyDkdQVrtO0UHCYOchA9N86wJaVceWpvlub1Xzg riyP3KCNCiPD/TMhryWoVksWECObLp53DQBxkeiUNcIr4pEQXwkN3nzOU1zHa1RtReXDrP GUxZf6LwGYUVbpz7a/8J1RByHz3Ndqo= ARC-Authentication-Results: i=1; imf17.hostedemail.com; dkim=pass header.d=chromium.org header.s=google header.b=n222AtNN; spf=pass (imf17.hostedemail.com: domain of senozhatsky@chromium.org designates 209.85.210.180 as permitted sender) smtp.mailfrom=senozhatsky@chromium.org; dmarc=pass (policy=none) header.from=chromium.org Received: by mail-pf1-f180.google.com with SMTP id d2e1a72fcca58-6da4a923b1bso5441696b3a.2 for ; Thu, 25 Jan 2024 19:12:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1706238762; x=1706843562; darn=kvack.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=lBA+mhnxqJOP4m7joWy+QwgY4c+lF7vio24SpkEJ2hc=; b=n222AtNNWT7XbeBlbyiGUrjhEvAD863w26mGOKMXerq0Cp2C+qLWMbE5oXQ+QZrzMr ztnoBl9wGm2gas0mECNVgfVuC2eVaRzIqoabUVqC5PVKy7dlTPK1/NeDn8Jh3HxFaz/I lw8gcnf1poUaxATHMDU4YnAcE9WOZowcDFchs= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1706238762; x=1706843562; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=lBA+mhnxqJOP4m7joWy+QwgY4c+lF7vio24SpkEJ2hc=; b=qUkPIr0pxpsuNrBQPDwvuYbDPiFnTXBwc/yF8Vs/lKrYBEsUHesEKqUMu0Clnx0R/l kal0gEFhjSp0oxHFN0/Sf9hmg/jAqfO+EIwtTEKYiBtEdnRQCjChNgbIIq8LSpMi6mfp AqvMRY5th87+nZN7WDDR+EUwTQ2GjsHWFM4jOw9McE9agvu8OLUX1LYJ7siZNOdwAcXM jxCaRQURbwn4N6bnKKtCX5rQ8lvwsWjnPFVM4+MxSrn3o9QkjGivnxe431I0XPiQFcKG keuDnLCbaMtyNYOPiRtnR0/SBVt9VNFP5Qq5ososIeIOqzl23vghKkRpzoHLzhhbDtN4 TGBQ== X-Gm-Message-State: AOJu0YygrKZ1+xaDyzU27vxoOqjFqXaK0EcfQWFbXQfHfIwY13yg7Bx4 KZu1kZ8bSt8nzYTuAIIsHoSTil3qxUwK/ALEgsouKZadi7nLa/NiM8e+jcIX0k5k4IYOqHOINgY = X-Google-Smtp-Source: AGHT+IF7R5606JWlYyzGGYDw0xQhCwb6MA5uJ4SwQAz4AExlZePc90aPQ/D4Yri9Mba2zBHAiX77ow== X-Received: by 2002:a05:6a20:918f:b0:19c:841b:35d2 with SMTP id v15-20020a056a20918f00b0019c841b35d2mr355738pzd.38.1706238762648; Thu, 25 Jan 2024 19:12:42 -0800 (PST) Received: from google.com ([2401:fa00:8f:203:c4a9:6453:1d67:60e8]) by smtp.gmail.com with ESMTPSA id jx14-20020a170903138e00b001d749017955sm199151plb.267.2024.01.25.19.12.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 25 Jan 2024 19:12:42 -0800 (PST) Date: Fri, 26 Jan 2024 12:12:38 +0900 From: Sergey Senozhatsky To: Andrew Morton , Jiexun Wang Cc: brauner@kernel.org, falcon@tinylab.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, tangjinyu@tinylab.org Subject: Re: [PATCH v2 1/1] mm/madvise: add cond_resched() in madvise_cold_or_pageout_pte_range() Message-ID: <20240126031238.GA329333@google.com> References: <85363861af65fac66c7a98c251906afc0d9c8098.1695291046.git.wangjiexun@tinylab.org> <20230921174101.8e6271422a857af5414ce0a0@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230921174101.8e6271422a857af5414ce0a0@linux-foundation.org> X-Stat-Signature: 9dqjdq94bon9r4jm9ho4y6o9xki1pgk4 X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: DE0D740009 X-Rspam-User: X-HE-Tag: 1706238763-75101 X-HE-Meta: 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 7yqTLrwQ bx8j5NMHn1gh7g006V1NBYFgN8Xdt5qfVbFtJcukct9lmCqspBHIm71IPuLnY60ZvZwmi8LkAU8rPNEo7wcsPT54/1t4Q3JdKKsHy3RHUps7KJMNK4W5MsCW6h5hN2QZLqVkPHFNEpsEwiERAR9byZeTYO6WsaKUpcsefcyvNIemtPFhAXxDJ5QaR+dphfkMk7WOGyI690rmncXPoiUxqLQF3pr/wXp3dithPHh268+s73O1TedjuGXHnXYTHRKicz79NaCIVNTj6x0Up419+xYjXZkDZsvqS2wErkLFp75CP3Ga6xMyu6cwDWk5jR/IOQkgB+6AyqWknk9QeoQ8tepKs0ICu9k7rRSm/2iCvcXCgPZZTYpXOUWf1+w== 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 (23/09/21 17:41), Andrew Morton wrote: > > Currently the madvise_cold_or_pageout_pte_range() function exhibits > > significant latency under memory pressure, which can be effectively > > reduced by adding cond_resched() within the loop. > > > > When the batch_count reaches SWAP_CLUSTER_MAX, we reschedule > > the task to ensure fairness and avoid long lock holding times. > > > > ... > > > > --- a/mm/madvise.c > > +++ b/mm/madvise.c > > @@ -354,6 +354,7 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, > > struct folio *folio = NULL; > > LIST_HEAD(folio_list); > > bool pageout_anon_only_filter; > > + unsigned int batch_count = 0; > > > > if (fatal_signal_pending(current)) > > return -EINTR; > > @@ -433,6 +434,7 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, > > regular_folio: > > #endif > > tlb_change_page_size(tlb, PAGE_SIZE); > > +restart: > > start_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); > > The handling of start_pte looks OK. > > > if (!start_pte) > > return 0; > > @@ -441,6 +443,15 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, > > for (; addr < end; pte++, addr += PAGE_SIZE) { > > ptent = ptep_get(pte); > > > > + if (++batch_count == SWAP_CLUSTER_MAX) { > > + batch_count = 0; > > + if (need_resched()) { > > + pte_unmap_unlock(start_pte, ptl); Shouldn't it leave lazy MMU mode here? --- diff --git a/mm/madvise.c b/mm/madvise.c index 0f222d464254..127f0c7b69ac 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -451,6 +451,7 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, if (++batch_count == SWAP_CLUSTER_MAX) { batch_count = 0; if (need_resched()) { + arch_leave_lazy_mmu_mode(); pte_unmap_unlock(start_pte, ptl); cond_resched(); goto restart;