From patchwork Wed Oct 25 14:45:43 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ryan Roberts X-Patchwork-Id: 13436306 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 09812C07545 for ; Wed, 25 Oct 2023 14:46:02 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 96A4A6B0329; Wed, 25 Oct 2023 10:46:01 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8EE136B032B; Wed, 25 Oct 2023 10:46:01 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 767EA6B032C; Wed, 25 Oct 2023 10:46:01 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 68C1A6B0329 for ; Wed, 25 Oct 2023 10:46:01 -0400 (EDT) Received: from smtpin26.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 21FEB140584 for ; Wed, 25 Oct 2023 14:46:01 +0000 (UTC) X-FDA: 81384258522.26.1AC7518 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf05.hostedemail.com (Postfix) with ESMTP id 6ED46100022 for ; Wed, 25 Oct 2023 14:45:59 +0000 (UTC) Authentication-Results: imf05.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf05.hostedemail.com: domain of ryan.roberts@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=ryan.roberts@arm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1698245159; 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-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=VVek/o5yzsqrP73thiBmSPOq8G6wi+ra9xSsWuMFlN8=; b=sLnp9lOFqxK1Vcj0tmpa9Fc9OspD+2hV6pee8VwUp+XQ02BmmrbO8CfV52j7VvFOJQQQMO LBQUvT/ksZVS8wIMrH5hAlxJSgi9mCF1StiORKEWTdxOsJzuCGpHAjtIy9VojUVgxe+vHH VRAq5HEhKrdJoLby6UDbBwXDvC2UBmM= ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf05.hostedemail.com: domain of ryan.roberts@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=ryan.roberts@arm.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1698245159; a=rsa-sha256; cv=none; b=xSvd22wPA3ZGHv1JITJZ6zCiszGLzmbIyrJE7/YAqXepL3HycEit4WOB83OoBtoBk5OCzP 8t/v6Prks8ZoweiZ9tWNUyHfRJ2rE2jKljueT0TnGkwL8L8Y+qzcw7tJheCVQ4HQQu5DKG fktO6UFBwMbB7vKhCMenHRuZBR9umy0= Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id BB8E1C15; Wed, 25 Oct 2023 07:46:39 -0700 (PDT) Received: from e125769.cambridge.arm.com (e125769.cambridge.arm.com [10.1.196.26]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 4EB863F64C; Wed, 25 Oct 2023 07:45:56 -0700 (PDT) From: Ryan Roberts To: Andrew Morton , David Hildenbrand , Matthew Wilcox , Huang Ying , Gao Xiang , Yu Zhao , Yang Shi , Michal Hocko , Kefeng Wang Cc: Ryan Roberts , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v3 1/4] mm: swap: Remove CLUSTER_FLAG_HUGE from swap_cluster_info:flags Date: Wed, 25 Oct 2023 15:45:43 +0100 Message-Id: <20231025144546.577640-2-ryan.roberts@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20231025144546.577640-1-ryan.roberts@arm.com> References: <20231025144546.577640-1-ryan.roberts@arm.com> MIME-Version: 1.0 X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 6ED46100022 X-Stat-Signature: 8mhqi1b7repjmusrin75ocwpb6yhdswe X-HE-Tag: 1698245159-102288 X-HE-Meta: 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 zRbskEWK S/5t2omOqWPeHE16huS0J574INuDxJq5TddNWBWtsq+EhwiunfbusbdnQVlxyzk5WG738ZD2kY+4OKPRjA+GwhTu3rVHqIQq+HEF+BnZSPdYkthMTlq/SrSR4a7YCzQJmClN0sxV9/utDvIU/VrB2WGFSRztBVmJYOuKKuwK2OL8Zo7TDxVd5+KvepZmfLzHm720eFSda/ICE38Y= 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: As preparation for supporting small-sized THP in the swap-out path, without first needing to split to order-0, Remove the CLUSTER_FLAG_HUGE, which, when present, always implies PMD-sized THP, which is the same as the cluster size. The only use of the flag was to determine whether a swap entry refers to a single page or a PMD-sized THP in swap_page_trans_huge_swapped(). Instead of relying on the flag, we now pass in nr_pages, which originates from the folio's number of pages. This allows the logic to work for folios of any order. The one snag is that one of the swap_page_trans_huge_swapped() call sites does not have the folio. But it was only being called there to avoid bothering to call __try_to_reclaim_swap() in some cases. __try_to_reclaim_swap() gets the folio and (via some other functions) calls swap_page_trans_huge_swapped(). So I've removed the problematic call site and believe the new logic should be equivalent. Removing CLUSTER_FLAG_HUGE also means we can remove split_swap_cluster() which used to be called during folio splitting, since split_swap_cluster()'s only job was to remove the flag. Signed-off-by: Ryan Roberts --- include/linux/swap.h | 10 ---------- mm/huge_memory.c | 3 --- mm/swapfile.c | 47 ++++++++------------------------------------ 3 files changed, 8 insertions(+), 52 deletions(-) diff --git a/include/linux/swap.h b/include/linux/swap.h index 19f30a29e1f1..a073366a227c 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -259,7 +259,6 @@ struct swap_cluster_info { }; #define CLUSTER_FLAG_FREE 1 /* This cluster is free */ #define CLUSTER_FLAG_NEXT_NULL 2 /* This cluster has no next cluster */ -#define CLUSTER_FLAG_HUGE 4 /* This cluster is backing a transparent huge page */ /* * We assign a cluster to each CPU, so each CPU can allocate swap entry from @@ -595,15 +594,6 @@ static inline int add_swap_extent(struct swap_info_struct *sis, } #endif /* CONFIG_SWAP */ -#ifdef CONFIG_THP_SWAP -extern int split_swap_cluster(swp_entry_t entry); -#else -static inline int split_swap_cluster(swp_entry_t entry) -{ - return 0; -} -#endif - #ifdef CONFIG_MEMCG static inline int mem_cgroup_swappiness(struct mem_cgroup *memcg) { diff --git a/mm/huge_memory.c b/mm/huge_memory.c index f31f02472396..b411dd4f1612 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2598,9 +2598,6 @@ static void __split_huge_page(struct page *page, struct list_head *list, shmem_uncharge(head->mapping->host, nr_dropped); remap_page(folio, nr); - if (folio_test_swapcache(folio)) - split_swap_cluster(folio->swap); - for (i = 0; i < nr; i++) { struct page *subpage = head + i; if (subpage == page) diff --git a/mm/swapfile.c b/mm/swapfile.c index e52f486834eb..b83ad77e04c0 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -342,18 +342,6 @@ static inline void cluster_set_null(struct swap_cluster_info *info) info->data = 0; } -static inline bool cluster_is_huge(struct swap_cluster_info *info) -{ - if (IS_ENABLED(CONFIG_THP_SWAP)) - return info->flags & CLUSTER_FLAG_HUGE; - return false; -} - -static inline void cluster_clear_huge(struct swap_cluster_info *info) -{ - info->flags &= ~CLUSTER_FLAG_HUGE; -} - static inline struct swap_cluster_info *lock_cluster(struct swap_info_struct *si, unsigned long offset) { @@ -1021,7 +1009,7 @@ static int swap_alloc_cluster(struct swap_info_struct *si, swp_entry_t *slot) offset = idx * SWAPFILE_CLUSTER; ci = lock_cluster(si, offset); alloc_cluster(si, idx); - cluster_set_count_flag(ci, SWAPFILE_CLUSTER, CLUSTER_FLAG_HUGE); + cluster_set_count(ci, SWAPFILE_CLUSTER); memset(si->swap_map + offset, SWAP_HAS_CACHE, SWAPFILE_CLUSTER); unlock_cluster(ci); @@ -1354,7 +1342,6 @@ void put_swap_folio(struct folio *folio, swp_entry_t entry) ci = lock_cluster_or_swap_info(si, offset); if (size == SWAPFILE_CLUSTER) { - VM_BUG_ON(!cluster_is_huge(ci)); map = si->swap_map + offset; for (i = 0; i < SWAPFILE_CLUSTER; i++) { val = map[i]; @@ -1362,7 +1349,6 @@ void put_swap_folio(struct folio *folio, swp_entry_t entry) if (val == SWAP_HAS_CACHE) free_entries++; } - cluster_clear_huge(ci); if (free_entries == SWAPFILE_CLUSTER) { unlock_cluster_or_swap_info(si, ci); spin_lock(&si->lock); @@ -1384,23 +1370,6 @@ void put_swap_folio(struct folio *folio, swp_entry_t entry) unlock_cluster_or_swap_info(si, ci); } -#ifdef CONFIG_THP_SWAP -int split_swap_cluster(swp_entry_t entry) -{ - struct swap_info_struct *si; - struct swap_cluster_info *ci; - unsigned long offset = swp_offset(entry); - - si = _swap_info_get(entry); - if (!si) - return -EBUSY; - ci = lock_cluster(si, offset); - cluster_clear_huge(ci); - unlock_cluster(ci); - return 0; -} -#endif - static int swp_entry_cmp(const void *ent1, const void *ent2) { const swp_entry_t *e1 = ent1, *e2 = ent2; @@ -1508,22 +1477,23 @@ int swp_swapcount(swp_entry_t entry) } static bool swap_page_trans_huge_swapped(struct swap_info_struct *si, - swp_entry_t entry) + swp_entry_t entry, + unsigned int nr_pages) { struct swap_cluster_info *ci; unsigned char *map = si->swap_map; unsigned long roffset = swp_offset(entry); - unsigned long offset = round_down(roffset, SWAPFILE_CLUSTER); + unsigned long offset = round_down(roffset, nr_pages); int i; bool ret = false; ci = lock_cluster_or_swap_info(si, offset); - if (!ci || !cluster_is_huge(ci)) { + if (!ci || nr_pages == 1) { if (swap_count(map[roffset])) ret = true; goto unlock_out; } - for (i = 0; i < SWAPFILE_CLUSTER; i++) { + for (i = 0; i < nr_pages; i++) { if (swap_count(map[offset + i])) { ret = true; break; @@ -1545,7 +1515,7 @@ static bool folio_swapped(struct folio *folio) if (!IS_ENABLED(CONFIG_THP_SWAP) || likely(!folio_test_large(folio))) return swap_swapcount(si, entry) != 0; - return swap_page_trans_huge_swapped(si, entry); + return swap_page_trans_huge_swapped(si, entry, folio_nr_pages(folio)); } /** @@ -1606,8 +1576,7 @@ int free_swap_and_cache(swp_entry_t entry) p = _swap_info_get(entry); if (p) { count = __swap_entry_free(p, entry); - if (count == SWAP_HAS_CACHE && - !swap_page_trans_huge_swapped(p, entry)) + if (count == SWAP_HAS_CACHE) __try_to_reclaim_swap(p, swp_offset(entry), TTRS_UNMAPPED | TTRS_FULL); }