From nobody Thu Apr 9 09:33:04 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C4F2AC433FE for ; Mon, 10 Oct 2022 11:02:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231987AbiJJLCL (ORCPT ); Mon, 10 Oct 2022 07:02:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40512 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231961AbiJJLCD (ORCPT ); Mon, 10 Oct 2022 07:02:03 -0400 Received: from SHSQR01.spreadtrum.com (mx1.unisoc.com [222.66.158.135]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0581C6D9FC; Mon, 10 Oct 2022 04:01:57 -0700 (PDT) Received: from SHSend.spreadtrum.com (bjmbx01.spreadtrum.com [10.0.64.7]) by SHSQR01.spreadtrum.com with ESMTPS id 29AB0i36074609 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NO); Mon, 10 Oct 2022 19:00:45 +0800 (CST) (envelope-from zhaoyang.huang@unisoc.com) Received: from bj03382pcu.spreadtrum.com (10.0.74.65) by BJMBX01.spreadtrum.com (10.0.64.7) with Microsoft SMTP Server (TLS) id 15.0.1497.23; Mon, 10 Oct 2022 19:00:44 +0800 From: "zhaoyang.huang" To: Andrew Morton , Matthew Wilcox , Vlastimil Babka , Zhaoyang Huang , , , , , Subject: [RFC PATCH] mm: skip GFP_IO if swap is zram only Date: Mon, 10 Oct 2022 19:00:22 +0800 Message-ID: <1665399622-20236-1-git-send-email-zhaoyang.huang@unisoc.com> X-Mailer: git-send-email 1.9.1 MIME-Version: 1.0 X-Originating-IP: [10.0.74.65] X-ClientProxiedBy: SHCAS03.spreadtrum.com (10.0.1.207) To BJMBX01.spreadtrum.com (10.0.64.7) X-MAIL: SHSQR01.spreadtrum.com 29AB0i36074609 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Zhaoyang Huang __GFP_IO is believed to prevent the allocation being suspended due to acces= sing physical block devices when reclaiming dirty pages. Zram is not considered = as such kind of device from kernel perspective of view. Do swap things if the = system is zram only. Signed-off-by: Zhaoyang Huang --- include/linux/swap.h | 1 + include/linux/swapfile.h | 1 - mm/swapfile.c | 7 +++++++ mm/vmscan.c | 3 ++- 4 files changed, 10 insertions(+), 2 deletions(-) diff --git a/include/linux/swap.h b/include/linux/swap.h index 43150b9..c160b2e 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -505,6 +505,7 @@ static inline long get_nr_swap_pages(void) extern int init_swap_address_space(unsigned int type, unsigned long nr_pag= es); extern void exit_swap_address_space(unsigned int type); extern struct swap_info_struct *get_swap_device(swp_entry_t entry); +extern bool if_swap_zram_only(void); sector_t swap_page_sector(struct page *page); =20 static inline void put_swap_device(struct swap_info_struct *si) diff --git a/include/linux/swapfile.h b/include/linux/swapfile.h index 5407854..e229c36 100644 --- a/include/linux/swapfile.h +++ b/include/linux/swapfile.h @@ -9,5 +9,4 @@ extern struct swap_info_struct *swap_info[]; extern unsigned long generic_max_swapfile_size(void); extern unsigned long max_swapfile_size(void); - #endif /* _LINUX_SWAPFILE_H */ diff --git a/mm/swapfile.c b/mm/swapfile.c index 1fdccd2..e1b2969 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -3663,6 +3663,13 @@ void __cgroup_throttle_swaprate(struct page *page, g= fp_t gfp_mask) } #endif =20 +bool if_swap_zram_only(void) +{ + return ((nr_swapfiles =3D=3D 1) + && !strncmp(swap_info[0]->bdev->bd_disk->disk_name, "zram", 4)); +} +EXPORT_SYMBOL_GPL(if_swap_zram_only); + static int __init swapfile_init(void) { int nid; diff --git a/mm/vmscan.c b/mm/vmscan.c index b2b1431..37500b5 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1770,7 +1770,8 @@ static unsigned int shrink_page_list(struct list_head= *page_list, */ if (folio_test_anon(folio) && folio_test_swapbacked(folio)) { if (!folio_test_swapcache(folio)) { - if (!(sc->gfp_mask & __GFP_IO)) + if (!(sc->gfp_mask & __GFP_IO) + && !if_swap_zram_only()) goto keep_locked; if (folio_maybe_dma_pinned(folio)) goto keep_locked; --=20 1.9.1