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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E9794C7EE2F for ; Mon, 12 Jun 2023 20:57:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238233AbjFLU5g (ORCPT ); Mon, 12 Jun 2023 16:57:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47842 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238232AbjFLU5Z (ORCPT ); Mon, 12 Jun 2023 16:57:25 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B4B549DE for ; Mon, 12 Jun 2023 13:53:09 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 643FC62D3A for ; Mon, 12 Jun 2023 20:51:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BA1A9C433EF; Mon, 12 Jun 2023 20:51:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1686603095; bh=OZ0suHeKr8bmBdyxXwqxJ+J1wM7964fFgZJN4Glp3XY=; h=Date:To:From:Subject:From; b=AuNkmiSaT3fFnVOhX98IZUCVaumQC1IrSNcY4X6ZGP5Esb6EpwUetu8wGX0chtsj4 rs9aqz+rZD3bK98r9bi2sSivVK3FQ0h8l0y+f41lt2wWcgOYC1vkaKzJOj6oGNvGMA 9MZd1lL3xdEkuuHqq2bNrgqHd25qnQbOZgLzk1fU= Date: Mon, 12 Jun 2023 13:51:35 -0700 To: mm-commits@vger.kernel.org, yosryahmed@google.com, vitaly.wool@konsulko.com, sjenning@redhat.com, senozhatsky@chromium.org, nphamcs@gmail.com, minchan@kernel.org, hannes@cmpxchg.org, ddstreet@ieee.org, cerasuolodomenico@gmail.com, akpm@linux-foundation.org From: Andrew Morton Subject: + mm-zswap-simplify-writeback-function.patch added to mm-unstable branch Message-Id: <20230612205135.BA1A9C433EF@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: mm: zswap: simplify writeback function has been added to the -mm mm-unstable branch. Its filename is mm-zswap-simplify-writeback-function.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-zswap-simplify-writeback-function.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Domenico Cerasuolo Subject: mm: zswap: simplify writeback function Date: Mon, 12 Jun 2023 11:38:14 +0200 zswap_writeback_entry() used to be a callback for the backends, which don't know about struct zswap_entry. Now that the only user is the generic zswap LRU reclaimer, it can be simplified: pass the pinned zswap_entry directly, and consolidate the refcount management in the shrink function. Link: https://lkml.kernel.org/r/20230612093815.133504-7-cerasuolodomenico@gmail.com Signed-off-by: Domenico Cerasuolo Tested-by: Yosry Ahmed Acked-by: Johannes Weiner Cc: Dan Streetman Cc: Minchan Kim Cc: Nhat Pham Cc: Sergey Senozhatsky Cc: Seth Jennings Cc: Vitaly Wool Signed-off-by: Andrew Morton --- mm/zswap.c | 70 +++++++++++++-------------------------------------- 1 file changed, 19 insertions(+), 51 deletions(-) --- a/mm/zswap.c~mm-zswap-simplify-writeback-function +++ a/mm/zswap.c @@ -254,7 +254,8 @@ static bool zswap_has_pool; pr_debug("%s pool %s/%s\n", msg, (p)->tfm_name, \ zpool_get_type((p)->zpool)) -static int zswap_writeback_entry(struct zpool *pool, unsigned long handle); +static int zswap_writeback_entry(struct zswap_entry *entry, struct zswap_header *zhdr, + struct zswap_tree *tree); static int zswap_pool_get(struct zswap_pool *pool); static void zswap_pool_put(struct zswap_pool *pool); @@ -635,7 +636,7 @@ static int zswap_reclaim_entry(struct zs zswap_entry_get(entry); spin_unlock(&tree->lock); - ret = zswap_writeback_entry(pool->zpool, entry->handle); + ret = zswap_writeback_entry(entry, zhdr, tree); spin_lock(&tree->lock); if (ret) { @@ -643,8 +644,17 @@ static int zswap_reclaim_entry(struct zs spin_lock(&pool->lru_lock); list_move(&entry->lru, &pool->lru); spin_unlock(&pool->lru_lock); + goto put_unlock; } + /* Check for invalidate() race */ + if (entry != zswap_rb_search(&tree->rbroot, swpoffset)) + goto put_unlock; + + /* Drop base reference */ + zswap_entry_put(tree, entry); + +put_unlock: /* Drop local reference */ zswap_entry_put(tree, entry); unlock: @@ -1045,16 +1055,14 @@ static int zswap_get_swap_cache_page(swp * the swap cache, the compressed version stored by zswap can be * freed. */ -static int zswap_writeback_entry(struct zpool *pool, unsigned long handle) +static int zswap_writeback_entry(struct zswap_entry *entry, struct zswap_header *zhdr, + struct zswap_tree *tree) { - struct zswap_header *zhdr; - swp_entry_t swpentry; - struct zswap_tree *tree; - pgoff_t offset; - struct zswap_entry *entry; + swp_entry_t swpentry = zhdr->swpentry; struct page *page; struct scatterlist input, output; struct crypto_acomp_ctx *acomp_ctx; + struct zpool *pool = entry->pool->zpool; u8 *src, *tmp = NULL; unsigned int dlen; @@ -1069,25 +1077,6 @@ static int zswap_writeback_entry(struct return -ENOMEM; } - /* extract swpentry from data */ - zhdr = zpool_map_handle(pool, handle, ZPOOL_MM_RO); - swpentry = zhdr->swpentry; /* here */ - tree = zswap_trees[swp_type(swpentry)]; - offset = swp_offset(swpentry); - zpool_unmap_handle(pool, handle); - - /* find and ref zswap entry */ - spin_lock(&tree->lock); - entry = zswap_entry_find_get(&tree->rbroot, offset); - if (!entry) { - /* entry was invalidated */ - spin_unlock(&tree->lock); - kfree(tmp); - return 0; - } - spin_unlock(&tree->lock); - BUG_ON(offset != entry->offset); - /* try to allocate swap cache page */ switch (zswap_get_swap_cache_page(swpentry, &page)) { case ZSWAP_SWAPCACHE_FAIL: /* no memory or invalidate happened */ @@ -1121,12 +1110,12 @@ static int zswap_writeback_entry(struct acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); dlen = PAGE_SIZE; - zhdr = zpool_map_handle(pool, handle, ZPOOL_MM_RO); + zhdr = zpool_map_handle(pool, entry->handle, ZPOOL_MM_RO); src = (u8 *)zhdr + sizeof(struct zswap_header); if (!zpool_can_sleep_mapped(pool)) { memcpy(tmp, src, entry->length); src = tmp; - zpool_unmap_handle(pool, handle); + zpool_unmap_handle(pool, entry->handle); } mutex_lock(acomp_ctx->mutex); @@ -1141,7 +1130,7 @@ static int zswap_writeback_entry(struct if (!zpool_can_sleep_mapped(pool)) kfree(tmp); else - zpool_unmap_handle(pool, handle); + zpool_unmap_handle(pool, entry->handle); BUG_ON(ret); BUG_ON(dlen != PAGE_SIZE); @@ -1158,23 +1147,7 @@ static int zswap_writeback_entry(struct put_page(page); zswap_written_back_pages++; - spin_lock(&tree->lock); - /* drop local reference */ - zswap_entry_put(tree, entry); - - /* - * There are two possible situations for entry here: - * (1) refcount is 1(normal case), entry is valid and on the tree - * (2) refcount is 0, entry is freed and not on the tree - * because invalidate happened during writeback - * search the tree and free the entry if find entry - */ - if (entry == zswap_rb_search(&tree->rbroot, offset)) - zswap_entry_put(tree, entry); - spin_unlock(&tree->lock); - return ret; - fail: if (!zpool_can_sleep_mapped(pool)) kfree(tmp); @@ -1183,13 +1156,8 @@ fail: * if we get here due to ZSWAP_SWAPCACHE_EXIST * a load may be happening concurrently. * it is safe and okay to not free the entry. - * if we free the entry in the following put * it is also okay to return !0 */ - spin_lock(&tree->lock); - zswap_entry_put(tree, entry); - spin_unlock(&tree->lock); - return ret; } _ Patches currently in -mm which might be from cerasuolodomenico@gmail.com are mm-zswap-add-pool-shrinking-mechanism.patch mm-zswap-remove-page-reclaim-logic-from-zbud.patch mm-zswap-remove-page-reclaim-logic-from-z3fold.patch mm-zswap-remove-page-reclaim-logic-from-zsmalloc.patch mm-zswap-remove-shrink-from-zpool-interface.patch mm-zswap-simplify-writeback-function.patch mm-zswap-remove-zswap_header.patch