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 D84F1C4332F for ; Thu, 6 Jan 2022 18:14:22 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4831A6B0071; Thu, 6 Jan 2022 13:14:22 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 433B16B0072; Thu, 6 Jan 2022 13:14:22 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2D3486B0074; Thu, 6 Jan 2022 13:14:22 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0020.hostedemail.com [216.40.44.20]) by kanga.kvack.org (Postfix) with ESMTP id 1FE756B0071 for ; Thu, 6 Jan 2022 13:14:22 -0500 (EST) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id D48BC1817903E for ; Thu, 6 Jan 2022 18:14:21 +0000 (UTC) X-FDA: 79000661922.12.27949AE Received: from mail-pj1-f41.google.com (mail-pj1-f41.google.com [209.85.216.41]) by imf22.hostedemail.com (Postfix) with ESMTP id 3273DC000F for ; Thu, 6 Jan 2022 18:14:20 +0000 (UTC) Received: by mail-pj1-f41.google.com with SMTP id n30-20020a17090a5aa100b001b2b6509685so4005374pji.3 for ; Thu, 06 Jan 2022 10:14:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=GoH2UN/8qkqabVyCewCEHBZi5Bqh3qhRr5ggOkTJFF4=; b=aQxvqSJhcL4KnFJO2E6onDSXG/6X25osguzKHpo2otgIlcDIu7jxz8hG4q7woDNfc3 ohTukTjB82nmeIRDqvrrOTmeaa0mILoVUemZ8wK/FjPJ1pzXBej44p5GNDLJQwVjc4Bb 2lYlh5Q4lIkvYynjiPb48LG7zS0HTbAyJb038jyJQC64PI4PiaWzNxpFRD/nIJxCN1ST So8uX/VfsET5sQymJzbQ6gki1PDxvdfLl5ltlriMOe+C1LfsSSl7t3C4vXTOVGPo3EOy NEb6djaIB22chEKBFUQUoE6AoYRGwXLeaR1T41NzfdDr9xa3XNGYktwSuCzUKHNyomrZ 7n9w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=GoH2UN/8qkqabVyCewCEHBZi5Bqh3qhRr5ggOkTJFF4=; b=gxVWRa8K56tFmXI9BzE4/LymwjhcvJADvPHI/G+bsOpyt46L0zGsbBOsL2g/53qhs+ HWZFmAq2ojLIZ0tiDg10dNrBWr4/SwH6a8lGh5Y1TGguXBHHIRCQWAikki1mlD5Mt5Ko 4wzaf7xwmD2LdBUe6sdyWGa8NCt/6pc4mKF82ha1pUsm106T4FMU8438avaYq6s9qAGQ rWPJjzekErkKK0A4+M0VGun4ehvO3zgmsC1hlIxHvsnYw5pEERQLXfQ0uMTLb8yqwUGK a0DLG8ZnA/jMuSAglfdqhwJrgsV0VXT5ya3YvOzRZmdBKGCwBJ5x04NVM1yefguDDDW4 6kHg== X-Gm-Message-State: AOAM532dQkKgeBLr2MZykEjKVvOhpFWIJA1yOasSrfGReOv/ZObLFBb0 Dn3KoSyP1UkLNs2xQcf5pZg= X-Google-Smtp-Source: ABdhPJzWO9L/JV+JRJxU8f2mZoQwRPPTOlhPOIY/mp+2/vFRiWi5b7QYr/uMrLmIH8AlJDVCRRpWtw== X-Received: by 2002:a17:90b:688:: with SMTP id m8mr5421498pjz.62.1641492860292; Thu, 06 Jan 2022 10:14:20 -0800 (PST) Received: from google.com ([2620:15c:211:201:e32:b92d:27fe:aa55]) by smtp.gmail.com with ESMTPSA id mw8sm2992238pjb.42.2022.01.06.10.14.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 06 Jan 2022 10:14:19 -0800 (PST) Date: Thu, 6 Jan 2022 10:14:17 -0800 From: Minchan Kim To: Andrew Morton Cc: Michal Hocko , David Hildenbrand , linux-mm , LKML , Suren Baghdasaryan , John Dias Subject: Re: [RESEND][PATCH v2] mm: don't call lru draining in the nested lru_cache_disable Message-ID: References: <20211230193627.495145-1-minchan@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211230193627.495145-1-minchan@kernel.org> X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 3273DC000F X-Stat-Signature: 4hwugqmn41na5nrzyqjpupz5toqyf7ex Authentication-Results: imf22.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=aQxvqSJh; spf=pass (imf22.hostedemail.com: domain of minchan.kim@gmail.com designates 209.85.216.41 as permitted sender) smtp.mailfrom=minchan.kim@gmail.com; dmarc=fail reason="SPF not aligned (relaxed), DKIM not aligned (relaxed)" header.from=kernel.org (policy=none) X-HE-Tag: 1641492860-311554 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: On Thu, Dec 30, 2021 at 11:36:27AM -0800, Minchan Kim wrote: > lru_cache_disable involves IPIs to drain pagevec of each core, > which sometimes takes quite long time to complete depending > on cpu's business, which makes allocation too slow up to > sveral hundredth milliseconds. Furthermore, the repeated draining > in the alloc_contig_range makes thing worse considering caller > of alloc_contig_range usually tries multiple times in the loop. > > This patch makes the lru_cache_disable aware of the fact the > pagevec was already disabled. With that, user of alloc_contig_range > can disable the lru cache in advance in their context during the > repeated trial so they can avoid the multiple costly draining > in cma allocation. Hi Folks, Any comment to proceed the work? > > Signed-off-by: Minchan Kim > --- > * from v1 - https://lore.kernel.org/lkml/20211206221006.946661-1-minchan@kernel.org/ > * fix lru_cache_disable race - akpm > > include/linux/swap.h | 14 ++------------ > mm/cma.c | 5 +++++ > mm/swap.c | 30 ++++++++++++++++++++++++++++-- > 3 files changed, 35 insertions(+), 14 deletions(-) > > diff --git a/include/linux/swap.h b/include/linux/swap.h > index ba52f3a3478e..fe18e86a4f13 100644 > --- a/include/linux/swap.h > +++ b/include/linux/swap.h > @@ -348,19 +348,9 @@ extern void lru_note_cost_page(struct page *); > extern void lru_cache_add(struct page *); > extern void mark_page_accessed(struct page *); > > -extern atomic_t lru_disable_count; > - > -static inline bool lru_cache_disabled(void) > -{ > - return atomic_read(&lru_disable_count); > -} > - > -static inline void lru_cache_enable(void) > -{ > - atomic_dec(&lru_disable_count); > -} > - > +extern bool lru_cache_disabled(void); > extern void lru_cache_disable(void); > +extern void lru_cache_enable(void); > extern void lru_add_drain(void); > extern void lru_add_drain_cpu(int cpu); > extern void lru_add_drain_cpu_zone(struct zone *zone); > diff --git a/mm/cma.c b/mm/cma.c > index 995e15480937..60be555c5b95 100644 > --- a/mm/cma.c > +++ b/mm/cma.c > @@ -30,6 +30,7 @@ > #include > #include > #include > +#include > #include > #include > > @@ -453,6 +454,8 @@ struct page *cma_alloc(struct cma *cma, unsigned long count, > if (bitmap_count > bitmap_maxno) > goto out; > > + lru_cache_disable(); > + > for (;;) { > spin_lock_irq(&cma->lock); > bitmap_no = bitmap_find_next_zero_area_off(cma->bitmap, > @@ -492,6 +495,8 @@ struct page *cma_alloc(struct cma *cma, unsigned long count, > start = bitmap_no + mask + 1; > } > > + lru_cache_enable(); > + > trace_cma_alloc_finish(cma->name, pfn, page, count, align); > > /* > diff --git a/mm/swap.c b/mm/swap.c > index af3cad4e5378..5f89d7c9a54e 100644 > --- a/mm/swap.c > +++ b/mm/swap.c > @@ -847,7 +847,17 @@ void lru_add_drain_all(void) > } > #endif /* CONFIG_SMP */ > > -atomic_t lru_disable_count = ATOMIC_INIT(0); > +static atomic_t lru_disable_count = ATOMIC_INIT(0); > + > +bool lru_cache_disabled(void) > +{ > + return atomic_read(&lru_disable_count) != 0; > +} > + > +void lru_cache_enable(void) > +{ > + atomic_dec(&lru_disable_count); > +} > > /* > * lru_cache_disable() needs to be called before we start compiling > @@ -859,7 +869,21 @@ atomic_t lru_disable_count = ATOMIC_INIT(0); > */ > void lru_cache_disable(void) > { > - atomic_inc(&lru_disable_count); > + static DEFINE_MUTEX(lock); > + > + /* > + * The lock gaurantees lru_cache is drained when the function > + * returned. > + */ > + mutex_lock(&lock); > + /* > + * If someone is already disabled lru_cache, just return with > + * increasing the lru_disable_count. > + */ > + if (atomic_inc_not_zero(&lru_disable_count)) { > + mutex_unlock(&lock); > + return; > + } > #ifdef CONFIG_SMP > /* > * lru_add_drain_all in the force mode will schedule draining on > @@ -873,6 +897,8 @@ void lru_cache_disable(void) > #else > lru_add_and_bh_lrus_drain(); > #endif > + atomic_inc(&lru_disable_count); > + mutex_unlock(&lock); > } > > /** > -- > 2.34.1.448.ga2b2bfdf31-goog >