From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1593918FC99; Tue, 10 Sep 2024 10:36:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725964567; cv=none; b=fr6CBVeM6ei+Kt4e4+G2pxrnp3cm2ITr5yCPLJWDLIf0IltBX7Vn1Pg0kN0dAYnSY0qVWixdK6I1imF3PcpXeEgPsETE5cW2Zd0OzQEwxRHjdRth8VAx0M9C21LA/e6cvEXtpBFNcXzrGsTR8z6I2nYLtFGrzWaE3+cEoP/zsC8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725964567; c=relaxed/simple; bh=BM4l4qvvzDPiqXAwXIMONFiQn8/+FSdbdExrqL7Dvp0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=FAJWE7xf7L9Uf/Q3zkHBspCQyvFX45ThJP07vvpftxGb2k0kXIAQpEhFBGe2v6hjv23NVMhUmFHKjT6eF0pcaUTdEmTerYpRgobfOjQONYfILIlu/rHIaqabfu4LUP/vjlpJeFLbKaZDaNMA66y1wBLPZUtOjFMKqnyk8kz2rdA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=a9B4S3Qg; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="a9B4S3Qg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 61E5CC4CEC3; Tue, 10 Sep 2024 10:36:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1725964567; bh=BM4l4qvvzDPiqXAwXIMONFiQn8/+FSdbdExrqL7Dvp0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=a9B4S3QggF/J+7IcfUgJe+YYoXsHm839gvJoqlLeUdKvVcK8R+6yoKxWhP3XJBA7c HrU9O9hJMSNGrp75BY1mUeAcVY/ZvHmhyu8+LWQ2g4ncmAHNGhMH4V2S4czS2X7bnq 4Y5a8j8B9QKSmKlK8mPqjmiwy0jcyKJgaXyQxMrs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Usama Arif , Johannes Weiner , Bharata B Rao , Breno Leitao , David Hildenbrand , Matthew Wilcox , Rik van Riel , Vlastimil Babka , Yu Zhao , Zhaoyang Huang , Zhaoyang Huang , Andrew Morton , Sasha Levin Subject: [PATCH 6.6 226/269] Revert "mm: skip CMA pages when they are not available" Date: Tue, 10 Sep 2024 11:33:33 +0200 Message-ID: <20240910092615.999695999@linuxfoundation.org> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240910092608.225137854@linuxfoundation.org> References: <20240910092608.225137854@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Usama Arif [ Upstream commit bfe0857c20c663fcc1592fa4e3a61ca12b07dac9 ] This reverts commit 5da226dbfce3 ("mm: skip CMA pages when they are not available") and b7108d66318a ("Multi-gen LRU: skip CMA pages when they are not eligible"). lruvec->lru_lock is highly contended and is held when calling isolate_lru_folios. If the lru has a large number of CMA folios consecutively, while the allocation type requested is not MIGRATE_MOVABLE, isolate_lru_folios can hold the lock for a very long time while it skips those. For FIO workload, ~150million order=0 folios were skipped to isolate a few ZONE_DMA folios [1]. This can cause lockups [1] and high memory pressure for extended periods of time [2]. Remove skipping CMA for MGLRU as well, as it was introduced in sort_folio for the same resaon as 5da226dbfce3a2f44978c2c7cf88166e69a6788b. [1] https://lore.kernel.org/all/CAOUHufbkhMZYz20aM_3rHZ3OcK4m2puji2FGpUpn_-DevGk3Kg@mail.gmail.com/ [2] https://lore.kernel.org/all/ZrssOrcJIDy8hacI@gmail.com/ [usamaarif642@gmail.com: also revert b7108d66318a, per Johannes] Link: https://lkml.kernel.org/r/9060a32d-b2d7-48c0-8626-1db535653c54@gmail.com Link: https://lkml.kernel.org/r/357ac325-4c61-497a-92a3-bdbd230d5ec9@gmail.com Link: https://lkml.kernel.org/r/9060a32d-b2d7-48c0-8626-1db535653c54@gmail.com Fixes: 5da226dbfce3 ("mm: skip CMA pages when they are not available") Signed-off-by: Usama Arif Acked-by: Johannes Weiner Cc: Bharata B Rao Cc: Breno Leitao Cc: David Hildenbrand Cc: Matthew Wilcox Cc: Rik van Riel Cc: Vlastimil Babka Cc: Yu Zhao Cc: Zhaoyang Huang Cc: Zhaoyang Huang Cc: Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin --- mm/vmscan.c | 24 ++---------------------- 1 file changed, 2 insertions(+), 22 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 7175ff9b97d9..81533bed0b46 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2261,25 +2261,6 @@ static __always_inline void update_lru_sizes(struct lruvec *lruvec, } -#ifdef CONFIG_CMA -/* - * It is waste of effort to scan and reclaim CMA pages if it is not available - * for current allocation context. Kswapd can not be enrolled as it can not - * distinguish this scenario by using sc->gfp_mask = GFP_KERNEL - */ -static bool skip_cma(struct folio *folio, struct scan_control *sc) -{ - return !current_is_kswapd() && - gfp_migratetype(sc->gfp_mask) != MIGRATE_MOVABLE && - folio_migratetype(folio) == MIGRATE_CMA; -} -#else -static bool skip_cma(struct folio *folio, struct scan_control *sc) -{ - return false; -} -#endif - /* * Isolating page from the lruvec to fill in @dst list by nr_to_scan times. * @@ -2326,8 +2307,7 @@ static unsigned long isolate_lru_folios(unsigned long nr_to_scan, nr_pages = folio_nr_pages(folio); total_scan += nr_pages; - if (folio_zonenum(folio) > sc->reclaim_idx || - skip_cma(folio, sc)) { + if (folio_zonenum(folio) > sc->reclaim_idx) { nr_skipped[folio_zonenum(folio)] += nr_pages; move_to = &folios_skipped; goto move; @@ -4971,7 +4951,7 @@ static bool sort_folio(struct lruvec *lruvec, struct folio *folio, struct scan_c } /* ineligible */ - if (zone > sc->reclaim_idx || skip_cma(folio, sc)) { + if (zone > sc->reclaim_idx) { gen = folio_inc_gen(lruvec, folio, false); list_move_tail(&folio->lru, &lrugen->folios[gen][type][zone]); return true; -- 2.43.0