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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 707B3C982DA for ; Sun, 20 Sep 2026 14:25:48 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8F6046B0098; Sun, 20 Sep 2026 10:25:47 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8CCE76B0099; Sun, 20 Sep 2026 10:25:47 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 809CF6B009B; Sun, 20 Sep 2026 10:25:47 -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 59C106B0098 for ; Sun, 20 Sep 2026 10:25:47 -0400 (EDT) Received: from smtpin09.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay04.hostedemail.com (Postfix) with ESMTP id D54491A0484 for ; Sun, 20 Sep 2026 14:25:46 +0000 (UTC) X-FDA: 85234364292.09.BBA88B1 Received: from outbound.st.icloud.com (st-2005d-snip4-5.eps.apple.com [57.103.79.58]) by imf12.hostedemail.com (Postfix) with ESMTP id D127F4000C for ; Sun, 20 Sep 2026 14:25:44 +0000 (UTC) Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=icloud.com header.s=1a1hai header.b=WQgQc6Sf; spf=pass (imf12.hostedemail.com: domain of zippermonkey@icloud.com designates 57.103.79.58 as permitted sender) smtp.mailfrom=zippermonkey@icloud.com; dmarc=pass (policy=quarantine) header.from=icloud.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1789914344; 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-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=5pw+tpdHx2j/84yt3i8Fgf/shxRk6ErVktUyAKNdLp4=; b=rZAonvfq92DM0iVv1ZPZWjznCzhSrpuJ2fdSqG4NWLLCLpHfJeWOz26PM9YgijwSkK22Uc wGx8RgVtbnuUhrrVOcr5rrZJQLZo/5dny8YKU/qzv5jMWcT/focEA1bD5NYeiD301K4oYW xYXuHcZR6kWpm0LojbNxfaTH0x0bOvo= ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1789914344; b=PJOjYuJk79PFeUOWkN1WDuRq3UVJ02vDZ0t0BoqaPYis6hyX+aJeRVeoU8OQ2lilENK0HD 4D4wUMSbF9jR9TxB3V2yCJD/yY/tmJIGLN2FTMrdlSRhWHLcQjEfcdlWCYTxf423u8eT3E g3Ik6XJJhYpVp2DyVJArktD+i7m/Ovk= ARC-Authentication-Results: i=1; imf12.hostedemail.com; dkim=pass header.d=icloud.com header.s=1a1hai header.b=WQgQc6Sf; spf=pass (imf12.hostedemail.com: domain of zippermonkey@icloud.com designates 57.103.79.58 as permitted sender) smtp.mailfrom=zippermonkey@icloud.com; dmarc=pass (policy=quarantine) header.from=icloud.com Received: from outbound.st.icloud.com (unknown [127.0.0.2]) by p00-icloudmta-asmtp-us-east-1a-60-percent-7 (Postfix) with ESMTPS id 99F261800297; Sun, 20 Sep 2026 14:25:41 +0000 (UTC) X-ICL-RepId: 01a0bf35-60c5-75c9-8b47-8dffd66b0e93 X-ICL-Out-Info: HUtFAUMEWwJACUgATUQeDx5WFlZNRAJCTQhKB0MGWQReCEsEQwFbEhVdRUkERxtXAlQXXQZSEnIZWhRcGFNFUR9UWFUJCgJRHFYNV0NUBF9QSxsOXABLWhVVFw4CQh9QH0wWV0NEHxwZWhRcGFNFUR9UWEMZRVZpQQtPHV0ZWxxCZFhXCQoCURxWDVdDVARfUFQRV1ALWQJCD0gKXwdGRB1KG1IDGhlXFlgbRwJFRkRBFEseCFRbBhQOSVAPAF0DME0dXQ5SBUZeWhdeUxcfSwBcRVoOWwRHFA== Dkim-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=icloud.com; s=1a1hai; t=1789914344; x=1792506344; bh=5pw+tpdHx2j/84yt3i8Fgf/shxRk6ErVktUyAKNdLp4=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:x-icloud-hme; b=WQgQc6SfBU1UTStyIAAHOgOXwoYXMfQzpHOvzXm9IHBmMIbz2YcQnssNwdomRlhZcSVIYKLlZxSnrXYTLFwwYetyubsGxM+RHTByhTnUhkwhvNMSc9dHGXPQnoxFzytkIhJCNTEHt6SRtzMrEJu+g9Z3+hIs/YbXtvLo4SnvtbTr4Du6Z1Qmhcs7KXoYPNRoHWg1imQrC2O8pIerTGswULO1lREstEw8yKLP+Bk+4OqKiuoVDp3AStlipTBS088F5LAvqiCV58ft1B4K1977IwJWs2e5nlNveYsmljdUpX/9vrSrVZHRgcI7htP3LMT3SByMwd/NkjNYTOdfGTQ92g== Received: from [127.0.0.1] (unknown [17.156.216.30]) by p00-icloudmta-asmtp-us-east-1a-60-percent-7 (Postfix) with ESMTPSA id C7131180028A; Sun, 20 Sep 2026 14:25:33 +0000 (UTC) From: Zhang Peng Date: Sun, 20 Sep 2026 22:24:16 +0800 Subject: [PATCH 3/4] mm/vmscan: extract folio pageout from shrink_folio_list() MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260920-vmscan-refactor-v1-3-ec04d71cb761@tencent.com> References: <20260920-vmscan-refactor-v1-0-ec04d71cb761@tencent.com> In-Reply-To: <20260920-vmscan-refactor-v1-0-ec04d71cb761@tencent.com> To: Andrew Morton , Kairui Song , Qi Zheng , Shakeel Butt , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Baoquan He , Baolin Wang , Johannes Weiner , David Hildenbrand , Michal Hocko , Lorenzo Stoakes Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Zhang Peng X-Mailer: b4 0.16.0 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwOTIwMDIxMCBTYWx0ZWRfXwXrX+1CQ9OqP qilit9DWHNxX4siHZVf6yDfELsJncHnl1Wz2qrUCrtD5BkDyowPT93npjQEtO59kiJTf456CAAr ZZIRJwAnM2UT0chAQ5i0V+F+hmeKfJl+3SHm7h86FYoZpU/mKff54IZZuFTGl/jHVHPPg8JULDO CZYJRkqZGE/TrJhrTaFgxKa8GiVzgt0SVbhzvYwB6bKOHELfdZAVC/86BfaOpZtHlHqGIGbWhnO hR9crLe0LUsT0rjYdR5TaXASz9rhqdM4lhbCTEHPUTPK3oy5E4+e4FFyIRw85fWHJ/sidiVtBMQ NgQVIsiSuVTbqIAQkIu9xLQxkcwBU3aE81FQQf7HdKKhxLILE2vENci9/Ifsbg= X-Proofpoint-GUID: XofwOTYfrX-FMP0KpQDBM3g2zGkwMuyn X-Authority-Info-Out: v=2.4 cv=R/8O2NRX c=1 sm=1 tr=0 ts=6aafece6 cx=c_apl:c_pps:t_out a=oyWFxbOnq+dmhQrAPgaJYA==:117 a=oyWFxbOnq+dmhQrAPgaJYA==:17 a=IkcTkHD0fZMA:10 a=VdqzKS8jKosA:10 a=x7bEGLp0ZPQA:10 a=YE32fvk_ji8A:10 a=VkNPw1HP01LnGYTKEx00:22 a=GvQkQWPkAAAA:8 a=qi0cjtEbl7ftujh0onEA:9 a=QEXdDO2ut3YA:10 a=J82S1U87d15UFHHUFZS8:22 a=J6hPbylVjWXjVQVODqME:22 X-Proofpoint-ORIG-GUID: XofwOTYfrX-FMP0KpQDBM3g2zGkwMuyn X-JNJ: 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 X-Stat-Signature: gry6jcphhzz8t5f5rrdkcike7fbkq6kb X-Rspam-User: X-Rspamd-Queue-Id: D127F4000C X-Rspamd-Server: rspam03 X-HE-Tag: 1789914344-619311 X-HE-Meta: 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 hvVAYkmc 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Zhang Peng shrink_folio_list() contains a self-contained pageout() dispatch state machine. Extract it into folio_try_pageout() so it can be reused by the batched pageout path. Return an explicit pageout result instead of a boolean. This keeps the important distinction between activating and merely keeping a folio visible to the caller, and also records whether a kept folio remains locked after pageout(). The clean and synchronous-write cases return FOLIO_PAGEOUT_FREE: the folio is still locked there, and shrink_folio_list() then runs its single folio_try_reclaim_free() call, so the reclaim-free step keeps exactly one caller. The PAGE_ACTIVATE arm no longer normalises nr_pages to 1 after a split: folio_activate_locked() derives the count from folio_nr_pages() itself, which is equal by construction once the folio is order-0. Note this makes the patch depend on patch 1; applying it alone would over-account nr_activate for a split shmem folio. No functional change. --- mm/vmscan.c | 100 ++++++++++++++++++++++++++++++++++++------------------------ 1 file changed, 61 insertions(+), 39 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 120085dfa2fe..3bce7ff89293 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1266,8 +1266,60 @@ static enum folio_reclaim_result folio_try_reclaim_free(struct folio *folio, return FOLIO_RECLAIM_SUCCESS; } +enum folio_pageout_result { + FOLIO_PAGEOUT_KEEP_LOCKED, + FOLIO_PAGEOUT_KEEP_UNLOCKED, + FOLIO_PAGEOUT_ACTIVATE, + FOLIO_PAGEOUT_FREE, /* folio is locked, hand it to folio_try_reclaim_free() */ +}; + +static enum folio_pageout_result folio_try_pageout(struct folio *folio, + struct scan_control *sc, struct swap_io_ctx *ctx, + struct list_head *folio_list) +{ + struct address_space *mapping = folio_mapping(folio); + unsigned int nr_pages = folio_nr_pages(folio); + + switch (pageout(ctx, mapping, folio, folio_list)) { + case PAGE_ACTIVATE: + /* + * If shmem folio is split when writeback to swap, the + * tail pages will make their own pass through this + * function and be accounted then. There is no need to + * clamp nr_pages here: folio_activate_locked() derives + * the count from folio_nr_pages() itself. + */ + if (nr_pages > 1 && !folio_test_large(folio)) + sc->nr_scanned -= (nr_pages - 1); + return FOLIO_PAGEOUT_ACTIVATE; + case PAGE_KEEP: + return FOLIO_PAGEOUT_KEEP_LOCKED; + case PAGE_SUCCESS: + if (nr_pages > 1 && !folio_test_large(folio)) + sc->nr_scanned -= (nr_pages - 1); + + if (folio_test_writeback(folio)) + return FOLIO_PAGEOUT_KEEP_UNLOCKED; + if (folio_test_dirty(folio)) + return FOLIO_PAGEOUT_KEEP_UNLOCKED; + + /* + * A synchronous write - probably a ramdisk. Go ahead + * and try to reclaim the folio. + */ + if (!folio_trylock(folio)) + return FOLIO_PAGEOUT_KEEP_UNLOCKED; + if (folio_test_dirty(folio) || folio_test_writeback(folio)) + return FOLIO_PAGEOUT_KEEP_LOCKED; + fallthrough; + case PAGE_CLEAN: + return FOLIO_PAGEOUT_FREE; + } + unreachable(); +} + /* - * shrink_folio_list() returns the number of reclaimed pages + * Reclaimed folios are counted in the return value. */ static unsigned int shrink_folio_list(struct list_head *folio_list, struct pglist_data *pgdat, struct scan_control *sc, @@ -1585,7 +1637,6 @@ static unsigned int shrink_folio_list(struct list_head *folio_list, if (folio_maybe_dma_pinned(folio)) goto activate_locked; - mapping = folio_mapping(folio); if (folio_test_dirty(folio)) { if (folio_is_file_lru(folio)) { /* @@ -1606,50 +1657,21 @@ static unsigned int shrink_folio_list(struct list_head *folio_list, goto keep_locked; if (!sc->may_writepage) goto keep_locked; - /* * Folio is dirty. Flush the TLB if a writable entry * potentially exists to avoid CPU writes after I/O * starts and then write it out here. */ try_to_unmap_flush_dirty(); - switch (pageout(&ctx, mapping, folio, folio_list)) { - case PAGE_KEEP: - goto keep_locked; - case PAGE_ACTIVATE: - /* - * If shmem folio is split when writeback to swap, - * the tail pages will make their own pass through - * this function and be accounted then. - */ - if (nr_pages > 1 && !folio_test_large(folio)) { - sc->nr_scanned -= (nr_pages - 1); - nr_pages = 1; - } + switch (folio_try_pageout(folio, sc, &ctx, folio_list)) { + case FOLIO_PAGEOUT_ACTIVATE: goto activate_locked; - case PAGE_SUCCESS: - if (nr_pages > 1 && !folio_test_large(folio)) { - sc->nr_scanned -= (nr_pages - 1); - nr_pages = 1; - } - if (folio_test_writeback(folio)) - goto keep; - if (folio_test_dirty(folio)) - goto keep; - - /* - * A synchronous write - probably a ramdisk. Go - * ahead and try to reclaim the folio. - */ - if (!folio_trylock(folio)) - goto keep; - if (folio_test_dirty(folio) || - folio_test_writeback(folio)) - goto keep_locked; - mapping = folio_mapping(folio); - fallthrough; - case PAGE_CLEAN: - ; /* try to free the folio below */ + case FOLIO_PAGEOUT_KEEP_LOCKED: + goto keep_locked; + case FOLIO_PAGEOUT_KEEP_UNLOCKED: + goto keep; + case FOLIO_PAGEOUT_FREE: + break; /* folio is locked; try to free it below */ } } -- 2.55.0