From patchwork Fri Mar 7 12:01:03 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qun-Wei Lin X-Patchwork-Id: 14006405 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 48960C19F32 for ; Fri, 7 Mar 2025 12:07:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type: Content-Transfer-Encoding:MIME-Version:References:In-Reply-To:Message-ID:Date :Subject:CC:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Oi/1yul7QoqCYVR3VHpPFv7fpZcX0xh49zK0QqiiehU=; b=uZqrC7T+FY8dNic0mA7imjOLu0 KoAANUEpZcC/t4AKR5/n3cIKCOLSzUwe46jKBTfbLhGF9E+s/2MPxqoESMXM+erRnVhQzgMiYBnnT HRsYnC7awGkmavtftWJ+lsvlQmUQ9dusqqAvDCar5iKqxyCugNGaT8MnpqsPUhZMGQEcQLQxe/vRR EcxBMx9wzza+6nsPNm/VSq2LUogwW5UhsWmNeNldUUdi4vFBozj9SgMtszUZjkWIaRo9+0vWOjvWa FZKBR+dqXu6rbrMTaTAP8pWfhmUclm4SdStZUkfxaC2iEUcecxF9o+enYaLzpL7xht5RcPxKUHz51 puYetgQw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tqWTb-0000000E8Z3-0en0; Fri, 07 Mar 2025 12:06:51 +0000 Received: from mailgw02.mediatek.com ([216.200.240.185]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tqWP4-0000000E7tM-4B4m; Fri, 07 Mar 2025 12:02:12 +0000 X-UUID: fcd0101cfb4b11efa1e849db4cc18d44-20250307 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mediatek.com; s=dk; h=Content-Type:Content-Transfer-Encoding:MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:CC:To:From; bh=Oi/1yul7QoqCYVR3VHpPFv7fpZcX0xh49zK0QqiiehU=; b=AEnGWX8xovgnGX01Gl48h0NnNYIMQZOLuMuEqdBX5eSvwetxP1BaxFubxbsK1nD47uupnsTVsXaijDSS6B9Yc5m9uE0z9+0cuF4iXyXdN8tx37LC/LnxR1YOBLCyud9iB95itFII2xl2AFl/pB+5L0xTd3bOTW7mqxHyw4vLyA8=; X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.2.1,REQID:8b03097a-411f-4017-bc34-7af2f44f399d,IP:0,UR L:0,TC:0,Content:-5,EDM:-25,RT:0,SF:0,FILE:0,BULK:0,RULE:Release_Ham,ACTIO N:release,TS:-30 X-CID-META: VersionHash:0ef645f,CLOUDID:460a168c-f5b8-47d5-8cf3-b68fe7530c9a,B ulkID:nil,BulkQuantity:0,Recheck:0,SF:81|82|102,TC:nil,Content:0|50,EDM:1, IP:nil,URL:0,File:nil,RT:nil,Bulk:nil,QS:nil,BEC:nil,COL:0,OSI:0,OSA:0,AV: 0,LES:1,SPR:NO,DKR:0,DKP:0,BRR:0,BRE:0,ARC:0 X-CID-BVR: 0 X-CID-BAS: 0,_,0,_ X-CID-FACTOR: TF_CID_SPAM_SNR X-UUID: fcd0101cfb4b11efa1e849db4cc18d44-20250307 Received: from mtkmbs11n1.mediatek.inc [(172.21.101.185)] by mailgw02.mediatek.com (envelope-from ) (musrelay.mediatek.com ESMTP with TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384 256/256) with ESMTP id 249684098; Fri, 07 Mar 2025 05:02:05 -0700 Received: from mtkmbs11n1.mediatek.inc (172.21.101.185) by mtkmbs13n2.mediatek.inc (172.21.101.108) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.28; Fri, 7 Mar 2025 20:02:01 +0800 Received: from mtksitap99.mediatek.inc (10.233.130.16) by mtkmbs11n1.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.2.1258.28 via Frontend Transport; Fri, 7 Mar 2025 20:02:01 +0800 From: Qun-Wei Lin To: Jens Axboe , Minchan Kim , Sergey Senozhatsky , Vishal Verma , Dan Williams , Dave Jiang , Ira Weiny , Andrew Morton , Matthias Brugger , AngeloGioacchino Del Regno , Chris Li , Ryan Roberts , "Huang, Ying" , Kairui Song , Dan Schatzberg , Barry Song , Al Viro CC: , , , , , , Casper Li , Chinwen Chang , Andrew Yang , James Hsu , Qun-Wei Lin Subject: [PATCH 1/2] mm: Split BLK_FEAT_SYNCHRONOUS and SWP_SYNCHRONOUS_IO into separate read and write flags Date: Fri, 7 Mar 2025 20:01:03 +0800 Message-ID: <20250307120141.1566673-2-qun-wei.lin@mediatek.com> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20250307120141.1566673-1-qun-wei.lin@mediatek.com> References: <20250307120141.1566673-1-qun-wei.lin@mediatek.com> MIME-Version: 1.0 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250307_040211_054544_F98444E1 X-CRM114-Status: GOOD ( 22.15 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org This patch splits the BLK_FEAT_SYNCHRONOUS feature flag into two separate flags: BLK_FEAT_READ_SYNCHRONOUS and BLK_FEAT_WRITE_SYNCHRONOUS. Similarly, the SWP_SYNCHRONOUS_IO flag is split into SWP_READ_SYNCHRONOUS_IO and SWP_WRITE_SYNCHRONOUS_IO. These changes are motivated by the need to better accommodate certain swap devices that support synchronous read operations but asynchronous write operations. The existing BLK_FEAT_SYNCHRONOUS and SWP_SYNCHRONOUS_IO flags are not sufficient for these devices, as they enforce synchronous behavior for both read and write operations. Signed-off-by: Qun-Wei Lin --- drivers/block/brd.c | 3 ++- drivers/block/zram/zram_drv.c | 5 +++-- drivers/nvdimm/btt.c | 3 ++- drivers/nvdimm/pmem.c | 5 +++-- include/linux/blkdev.h | 24 ++++++++++++++++-------- include/linux/swap.h | 31 ++++++++++++++++--------------- mm/memory.c | 4 ++-- mm/page_io.c | 6 +++--- mm/swapfile.c | 7 +++++-- 9 files changed, 52 insertions(+), 36 deletions(-) diff --git a/drivers/block/brd.c b/drivers/block/brd.c index 292f127cae0a..66920b9d4701 100644 --- a/drivers/block/brd.c +++ b/drivers/block/brd.c @@ -370,7 +370,8 @@ static int brd_alloc(int i) .max_hw_discard_sectors = UINT_MAX, .max_discard_segments = 1, .discard_granularity = PAGE_SIZE, - .features = BLK_FEAT_SYNCHRONOUS | + .features = BLK_FEAT_READ_SYNCHRONOUS | + BLK_FEAT_WRITE_SYNCHRONOUS | BLK_FEAT_NOWAIT, }; diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 3dee026988dc..2e1a70f2f4bd 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -2535,8 +2535,9 @@ static int zram_add(void) #if ZRAM_LOGICAL_BLOCK_SIZE == PAGE_SIZE .max_write_zeroes_sectors = UINT_MAX, #endif - .features = BLK_FEAT_STABLE_WRITES | - BLK_FEAT_SYNCHRONOUS, + .features = BLK_FEAT_STABLE_WRITES | + BLK_FEAT_READ_SYNCHRONOUS | + BLK_FEAT_WRITE_SYNCHRONOUS, }; struct zram *zram; int ret, device_id; diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c index 423dcd190906..1665d98f51af 100644 --- a/drivers/nvdimm/btt.c +++ b/drivers/nvdimm/btt.c @@ -1501,7 +1501,8 @@ static int btt_blk_init(struct btt *btt) .logical_block_size = btt->sector_size, .max_hw_sectors = UINT_MAX, .max_integrity_segments = 1, - .features = BLK_FEAT_SYNCHRONOUS, + .features = BLK_FEAT_READ_SYNCHRONOUS | + BLK_FEAT_WRITE_SYNCHRONOUS, }; int rc; diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index d81faa9d89c9..81a57d7ca746 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -455,8 +455,9 @@ static int pmem_attach_disk(struct device *dev, .logical_block_size = pmem_sector_size(ndns), .physical_block_size = PAGE_SIZE, .max_hw_sectors = UINT_MAX, - .features = BLK_FEAT_WRITE_CACHE | - BLK_FEAT_SYNCHRONOUS, + .features = BLK_FEAT_WRITE_CACHE | + BLK_FEAT_READ_SYNCHRONOUS | + BLK_FEAT_WRITE_SYNCHRONOUS, }; int nid = dev_to_node(dev), fua; struct resource *res = &nsio->res; diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 08a727b40816..3070f2e9d862 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -305,20 +305,23 @@ typedef unsigned int __bitwise blk_features_t; /* don't modify data until writeback is done */ #define BLK_FEAT_STABLE_WRITES ((__force blk_features_t)(1u << 5)) -/* always completes in submit context */ -#define BLK_FEAT_SYNCHRONOUS ((__force blk_features_t)(1u << 6)) +/* read operations always completes in submit context */ +#define BLK_FEAT_READ_SYNCHRONOUS ((__force blk_features_t)(1u << 6)) + +/* write operations always completes in submit context */ +#define BLK_FEAT_WRITE_SYNCHRONOUS ((__force blk_features_t)(1u << 7)) /* supports REQ_NOWAIT */ -#define BLK_FEAT_NOWAIT ((__force blk_features_t)(1u << 7)) +#define BLK_FEAT_NOWAIT ((__force blk_features_t)(1u << 8)) /* supports DAX */ -#define BLK_FEAT_DAX ((__force blk_features_t)(1u << 8)) +#define BLK_FEAT_DAX ((__force blk_features_t)(1u << 9)) /* supports I/O polling */ -#define BLK_FEAT_POLL ((__force blk_features_t)(1u << 9)) +#define BLK_FEAT_POLL ((__force blk_features_t)(1u << 10)) /* is a zoned device */ -#define BLK_FEAT_ZONED ((__force blk_features_t)(1u << 10)) +#define BLK_FEAT_ZONED ((__force blk_features_t)(1u << 11)) /* supports PCI(e) p2p requests */ #define BLK_FEAT_PCI_P2PDMA ((__force blk_features_t)(1u << 12)) @@ -1321,9 +1324,14 @@ static inline bool bdev_nonrot(struct block_device *bdev) return blk_queue_nonrot(bdev_get_queue(bdev)); } -static inline bool bdev_synchronous(struct block_device *bdev) +static inline bool bdev_read_synchronous(struct block_device *bdev) +{ + return bdev->bd_disk->queue->limits.features & BLK_FEAT_READ_SYNCHRONOUS; +} + +static inline bool bdev_write_synchronous(struct block_device *bdev) { - return bdev->bd_disk->queue->limits.features & BLK_FEAT_SYNCHRONOUS; + return bdev->bd_disk->queue->limits.features & BLK_FEAT_WRITE_SYNCHRONOUS; } static inline bool bdev_stable_writes(struct block_device *bdev) diff --git a/include/linux/swap.h b/include/linux/swap.h index f3e0ac20c2e8..2068b6973648 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -205,21 +205,22 @@ struct swap_extent { offsetof(union swap_header, info.badpages)) / sizeof(int)) enum { - SWP_USED = (1 << 0), /* is slot in swap_info[] used? */ - SWP_WRITEOK = (1 << 1), /* ok to write to this swap? */ - SWP_DISCARDABLE = (1 << 2), /* blkdev support discard */ - SWP_DISCARDING = (1 << 3), /* now discarding a free cluster */ - SWP_SOLIDSTATE = (1 << 4), /* blkdev seeks are cheap */ - SWP_CONTINUED = (1 << 5), /* swap_map has count continuation */ - SWP_BLKDEV = (1 << 6), /* its a block device */ - SWP_ACTIVATED = (1 << 7), /* set after swap_activate success */ - SWP_FS_OPS = (1 << 8), /* swapfile operations go through fs */ - SWP_AREA_DISCARD = (1 << 9), /* single-time swap area discards */ - SWP_PAGE_DISCARD = (1 << 10), /* freed swap page-cluster discards */ - SWP_STABLE_WRITES = (1 << 11), /* no overwrite PG_writeback pages */ - SWP_SYNCHRONOUS_IO = (1 << 12), /* synchronous IO is efficient */ - /* add others here before... */ - SWP_SCANNING = (1 << 14), /* refcount in scan_swap_map */ + SWP_USED = (1 << 0), /* is slot in swap_info[] used? */ + SWP_WRITEOK = (1 << 1), /* ok to write to this swap? */ + SWP_DISCARDABLE = (1 << 2), /* blkdev support discard */ + SWP_DISCARDING = (1 << 3), /* now discarding a free cluster */ + SWP_SOLIDSTATE = (1 << 4), /* blkdev seeks are cheap */ + SWP_CONTINUED = (1 << 5), /* swap_map has count continuation */ + SWP_BLKDEV = (1 << 6), /* its a block device */ + SWP_ACTIVATED = (1 << 7), /* set after swap_activate success */ + SWP_FS_OPS = (1 << 8), /* swapfile operations go through fs */ + SWP_AREA_DISCARD = (1 << 9), /* single-time swap area discards */ + SWP_PAGE_DISCARD = (1 << 10), /* freed swap page-cluster discards */ + SWP_STABLE_WRITES = (1 << 11), /* no overwrite PG_writeback pages */ + SWP_READ_SYNCHRONOUS_IO = (1 << 12), /* synchronous read IO is efficient */ + SWP_WRITE_SYNCHRONOUS_IO = (1 << 13), /* synchronous write IO is efficient */ + SWP_SCANNING = (1 << 14), /* refcount in scan_swap_map */ + /* add others here before... */ }; #define SWAP_CLUSTER_MAX 32UL diff --git a/mm/memory.c b/mm/memory.c index 75c2dfd04f72..56c864d5d787 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -4293,7 +4293,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) swapcache = folio; if (!folio) { - if (data_race(si->flags & SWP_SYNCHRONOUS_IO) && + if (data_race(si->flags & SWP_READ_SYNCHRONOUS_IO) && __swap_count(entry) == 1) { /* skip swapcache */ folio = alloc_swap_folio(vmf); @@ -4430,7 +4430,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) goto out_nomap; } - /* allocated large folios for SWP_SYNCHRONOUS_IO */ + /* allocated large folios for SWP_READ_SYNCHRONOUS_IO */ if (folio_test_large(folio) && !folio_test_swapcache(folio)) { unsigned long nr = folio_nr_pages(folio); unsigned long folio_start = ALIGN_DOWN(vmf->address, nr * PAGE_SIZE); diff --git a/mm/page_io.c b/mm/page_io.c index 4b4ea8e49cf6..d692eafdd90c 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -465,10 +465,10 @@ void __swap_writepage(struct folio *folio, struct writeback_control *wbc) swap_writepage_fs(folio, wbc); /* * ->flags can be updated non-atomicially (scan_swap_map_slots), - * but that will never affect SWP_SYNCHRONOUS_IO, so the data_race + * but that will never affect SWP_WRITE_SYNCHRONOUS_IO, so the data_race * is safe. */ - else if (data_race(sis->flags & SWP_SYNCHRONOUS_IO)) + else if (data_race(sis->flags & SWP_WRITE_SYNCHRONOUS_IO)) swap_writepage_bdev_sync(folio, wbc, sis); else swap_writepage_bdev_async(folio, wbc, sis); @@ -616,7 +616,7 @@ static void swap_read_folio_bdev_async(struct folio *folio, void swap_read_folio(struct folio *folio, struct swap_iocb **plug) { struct swap_info_struct *sis = swp_swap_info(folio->swap); - bool synchronous = sis->flags & SWP_SYNCHRONOUS_IO; + bool synchronous = sis->flags & SWP_READ_SYNCHRONOUS_IO; bool workingset = folio_test_workingset(folio); unsigned long pflags; bool in_thrashing; diff --git a/mm/swapfile.c b/mm/swapfile.c index b0a9071cfe1d..902e5698af44 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -3488,8 +3488,11 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) if (si->bdev && bdev_stable_writes(si->bdev)) si->flags |= SWP_STABLE_WRITES; - if (si->bdev && bdev_synchronous(si->bdev)) - si->flags |= SWP_SYNCHRONOUS_IO; + if (si->bdev && bdev_read_synchronous(si->bdev)) + si->flags |= SWP_READ_SYNCHRONOUS_IO; + + if (si->bdev && bdev_write_synchronous(si->bdev)) + si->flags |= SWP_WRITE_SYNCHRONOUS_IO; if (si->bdev && bdev_nonrot(si->bdev)) { si->flags |= SWP_SOLIDSTATE;