From nobody Mon Apr 6 15:52:22 2026 Received: from mailgw.kylinos.cn (mailgw.kylinos.cn [124.126.103.232]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CF5CE270552 for ; Thu, 19 Mar 2026 01:29:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=124.126.103.232 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773883746; cv=none; b=u+NMB0R9YC0j+u7alO//jm929vFjF53VitTs/u4ZtYB343uxiU4a0jppjaobFVeY32R25zmk98uTBmqxg0N7Cq8yivxdCbtS5hc2KfyijDyOaA7BstwwAcNUOecKdsYfZIbE5uc6xc4UREAfpzV/G/wcyJNwPx/UXSK683FXUnw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773883746; c=relaxed/simple; bh=+uCvF6KPBMO6w5285ovu2pSmpxnqmYGzsR0GjNb1zms=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=PgoTVyNBmLdrt5cjGMlvxJy2v9gylG4HYU7O5afCnIEIbqICslXF9bDIwEuObZyeXfwQYKECJP+FGrCb4fSlMY32R72pG5qiKFTYiD34BW21G0r3hYf4Ld8kjfFI0EMg1H0+MioSqRejxl56GUUHR4qGkU3JxeOnx0zdAn+c8KI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn; spf=pass smtp.mailfrom=kylinos.cn; arc=none smtp.client-ip=124.126.103.232 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kylinos.cn X-UUID: fd09db3e233211f1a21c59e7364eecb8-20260319 X-CTIC-Tags: HR_CC_COUNT, HR_CC_DOMAIN_COUNT, HR_CC_NO_NAME, HR_CTE_8B, HR_CTT_MISS HR_DATE_H, HR_DATE_WKD, HR_DATE_ZONE, HR_FROM_NAME, HR_SJ_DIGIT_LEN HR_SJ_LANG, HR_SJ_LEN, HR_SJ_LETTER, HR_SJ_NOR_SYM, HR_SJ_PHRASE HR_SJ_PHRASE_LEN, HR_SJ_WS, HR_TO_COUNT, HR_TO_DOMAIN_COUNT, HR_TO_NO_NAME IP_TRUSTED, SRC_TRUSTED, DN_TRUSTED, SA_EXISTED, SN_EXISTED SPF_NOPASS, DKIM_NOPASS, DMARC_NOPASS, CIE_GOOD, CIE_GOOD_SPF GTI_FG_BS, GTI_RG_INFO, GTI_C_BU, AMN_GOOD, ABX_MISS_RDNS X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.3.11,REQID:3fe70b73-3617-40ab-8f12-bfbdd59bc9a7,IP:10, URL:0,TC:0,Content:-5,EDM:0,RT:0,SF:-5,FILE:0,BULK:0,RULE:Release_Ham,ACTI ON:release,TS:0 X-CID-INFO: VERSION:1.3.11,REQID:3fe70b73-3617-40ab-8f12-bfbdd59bc9a7,IP:10,UR L:0,TC:0,Content:-5,EDM:0,RT:0,SF:-5,FILE:0,BULK:0,RULE:Release_Ham,ACTION :release,TS:0 X-CID-META: VersionHash:89c9d04,CLOUDID:8e9051a4baa071bd9e6ba1e2fd41ff08,BulkI D:260319092854E2BZI7TH,BulkQuantity:0,Recheck:0,SF:17|19|38|66|78|81|82|10 2|127|850|898,TC:nil,Content:0|15|50,EDM:-3,IP:-2,URL:0,File:nil,RT:nil,Bu lk: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: 2,SSN|SDN X-CID-BAS: 2,SSN|SDN,0,_ X-CID-FACTOR: TF_CID_SPAM_SNR,TF_CID_SPAM_FAS,TF_CID_SPAM_FSD X-CID-RHF: D41D8CD98F00B204E9800998ECF8427E X-UUID: fd09db3e233211f1a21c59e7364eecb8-20260319 X-User: duanchenghao@kylinos.cn Received: from localhost.localdomain [(183.242.174.22)] by mailgw.kylinos.cn (envelope-from ) (Generic MTA) with ESMTP id 407130314; Thu, 19 Mar 2026 09:28:52 +0800 From: Chenghao Duan To: pasha.tatashin@soleen.com, rppt@kernel.org, pratyush@kernel.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: duanchenghao@kylinos.cn, jianghaoran@kylinos.cn Subject: [PATCH v1 1/3] mm/memfd_luo: optimize shmem_recalc_inode calls in retrieve path Date: Thu, 19 Mar 2026 09:28:43 +0800 Message-Id: <20260319012845.29570-2-duanchenghao@kylinos.cn> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20260319012845.29570-1-duanchenghao@kylinos.cn> References: <20260319012845.29570-1-duanchenghao@kylinos.cn> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Move shmem_recalc_inode() out of the loop in memfd_luo_retrieve_folios() to improve performance when restoring large memfds. Currently, shmem_recalc_inode() is called for each folio during restore, which is O(n) expensive operations. This patch collects the number of successfully added folios and calls shmem_recalc_inode() once after the loop completes, reducing complexity to O(1). Additionally, fix the error path to also call shmem_recalc_inode() for the folios that were successfully added before the error occurred. Signed-off-by: Chenghao Duan Reviewed-by: Pasha Tatashin --- mm/memfd_luo.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/mm/memfd_luo.c b/mm/memfd_luo.c index b8edb9f981d7..5ddd3657d8be 100644 --- a/mm/memfd_luo.c +++ b/mm/memfd_luo.c @@ -397,6 +397,7 @@ static int memfd_luo_retrieve_folios(struct file *file, struct folio *folio; int err =3D -EIO; long i; + u64 nr_added =3D 0; =20 for (i =3D 0; i < nr_folios; i++) { const struct memfd_luo_folio_ser *pfolio =3D &folios_ser[i]; @@ -448,12 +449,15 @@ static int memfd_luo_retrieve_folios(struct file *fil= e, goto unlock_folio; } =20 - shmem_recalc_inode(inode, 1, 0); + nr_added++; folio_add_lru(folio); folio_unlock(folio); folio_put(folio); } =20 + if (nr_added) + shmem_recalc_inode(inode, nr_added, 0); + return 0; =20 unlock_folio: @@ -472,6 +476,9 @@ static int memfd_luo_retrieve_folios(struct file *file, folio_put(folio); } =20 + if (nr_added) + shmem_recalc_inode(inode, nr_added, 0); + return err; } =20 --=20 2.25.1 From nobody Mon Apr 6 15:52:22 2026 Received: from mailgw.kylinos.cn (mailgw.kylinos.cn [124.126.103.232]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D7A1D280309 for ; 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Thu, 19 Mar 2026 09:28:53 +0800 From: Chenghao Duan To: pasha.tatashin@soleen.com, rppt@kernel.org, pratyush@kernel.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: duanchenghao@kylinos.cn, jianghaoran@kylinos.cn Subject: [PATCH v1 2/3] mm/memfd_luo: remove unnecessary memset in zero-size memfd path Date: Thu, 19 Mar 2026 09:28:44 +0800 Message-Id: <20260319012845.29570-3-duanchenghao@kylinos.cn> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20260319012845.29570-1-duanchenghao@kylinos.cn> References: <20260319012845.29570-1-duanchenghao@kylinos.cn> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The memset(kho_vmalloc, 0, sizeof(*kho_vmalloc)) call in the zero-size file handling path is unnecessary because the allocation of the ser structure already uses the __GFP_ZERO flag, ensuring the memory is already zero-initialized. Signed-off-by: Chenghao Duan Reviewed-by: Mike Rapoport (Microsoft) Reviewed-by: Pasha Tatashin Reviewed-by: Pratyush Yadav --- mm/memfd_luo.c | 1 - 1 file changed, 1 deletion(-) diff --git a/mm/memfd_luo.c b/mm/memfd_luo.c index 5ddd3657d8be..413df8c75c1d 100644 --- a/mm/memfd_luo.c +++ b/mm/memfd_luo.c @@ -103,7 +103,6 @@ static int memfd_luo_preserve_folios(struct file *file, if (!size) { *nr_foliosp =3D 0; *out_folios_ser =3D NULL; - memset(kho_vmalloc, 0, sizeof(*kho_vmalloc)); return 0; } =20 --=20 2.25.1 From nobody Mon Apr 6 15:52:22 2026 Received: from mailgw.kylinos.cn (mailgw.kylinos.cn [124.126.103.232]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3C04527E04C for ; Thu, 19 Mar 2026 01:29:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=124.126.103.232 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773883747; cv=none; b=HsEM0cZG5Xrt7OMErY/zWZBzFTxu+/+05JzIbIdeXcjY1A5fZj9Qr5CA0XUqFVGA425gByCC8Le/hhM+k1Un21Sdpx38FmwDkwymJVwX0vn6K0YqRExi/eWepmr3UIUHjrE8BHsezbmC3FCM3giA/rK3m+X4X8kVnuVwJotNaCU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773883747; c=relaxed/simple; bh=2Qra5vI+fsl4kHgFmxrqNHOA/FegjBghM87mUlpnYKM=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=qMF2sLISi48Q3vRTJhpTeQC24c5sNFchzC5tjwdhgAlHTXmz9denagafmwg/JHu+OHVwsi19qNsR+N+VgAGfviNaVXVBe2wvlzu21Hp3MVeoBOTK7H0/l3LM83RX/X7JjMLem5O1h3jt67qyLcmMWQZ0AHWtNA24A2AOcrgXOvo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn; spf=pass smtp.mailfrom=kylinos.cn; arc=none smtp.client-ip=124.126.103.232 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kylinos.cn X-UUID: fe2642e6233211f1a21c59e7364eecb8-20260319 X-CTIC-Tags: HR_CC_COUNT, HR_CC_DOMAIN_COUNT, HR_CC_NO_NAME, HR_CTE_8B, HR_CTT_MISS HR_DATE_H, HR_DATE_WKD, HR_DATE_ZONE, HR_FROM_NAME, HR_SJ_DIGIT_LEN HR_SJ_LANG, HR_SJ_LEN, HR_SJ_LETTER, HR_SJ_NOR_SYM, HR_SJ_PHRASE HR_SJ_PHRASE_LEN, HR_SJ_WS, HR_TO_COUNT, HR_TO_DOMAIN_COUNT, HR_TO_NO_NAME IP_TRUSTED, SRC_TRUSTED, DN_TRUSTED, SA_EXISTED, SN_EXISTED SPF_NOPASS, DKIM_NOPASS, DMARC_NOPASS, CIE_GOOD, CIE_GOOD_SPF GTI_FG_BS, GTI_RG_INFO, GTI_C_BU, AMN_GOOD, ABX_MISS_RDNS X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.3.11,REQID:caf5b2b3-d0e6-40c8-b11e-a43a30cf23c2,IP:10, URL:0,TC:0,Content:0,EDM:0,RT:0,SF:-5,FILE:0,BULK:0,RULE:Release_Ham,ACTIO N:release,TS:5 X-CID-INFO: VERSION:1.3.11,REQID:caf5b2b3-d0e6-40c8-b11e-a43a30cf23c2,IP:10,UR L:0,TC:0,Content:0,EDM:0,RT:0,SF:-5,FILE:0,BULK:0,RULE:Release_Ham,ACTION: release,TS:5 X-CID-META: VersionHash:89c9d04,CLOUDID:0ffdf6325e8b88ba6818234b35eb601e,BulkI D:260319092857GKQUZZA9,BulkQuantity:0,Recheck:0,SF:17|19|38|66|78|81|82|10 2|127|850|898,TC:nil,Content:0|15|50,EDM:-3,IP:-2,URL:0,File:nil,RT:nil,Bu lk: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: 2,SSN|SDN X-CID-BAS: 2,SSN|SDN,0,_ X-CID-FACTOR: TF_CID_SPAM_SNR,TF_CID_SPAM_FAS,TF_CID_SPAM_FSD X-CID-RHF: D41D8CD98F00B204E9800998ECF8427E X-UUID: fe2642e6233211f1a21c59e7364eecb8-20260319 X-User: duanchenghao@kylinos.cn Received: from localhost.localdomain [(183.242.174.22)] by mailgw.kylinos.cn (envelope-from ) (Generic MTA) with ESMTP id 178793136; Thu, 19 Mar 2026 09:28:54 +0800 From: Chenghao Duan To: pasha.tatashin@soleen.com, rppt@kernel.org, pratyush@kernel.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: duanchenghao@kylinos.cn, jianghaoran@kylinos.cn Subject: [PATCH v1 3/3] mm/memfd_luo: use i_size_write() to set inode size during retrieve Date: Thu, 19 Mar 2026 09:28:45 +0800 Message-Id: <20260319012845.29570-4-duanchenghao@kylinos.cn> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20260319012845.29570-1-duanchenghao@kylinos.cn> References: <20260319012845.29570-1-duanchenghao@kylinos.cn> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Use i_size_write() instead of directly assigning to inode->i_size when restoring the memfd size in memfd_luo_retrieve(). No functional change intended. Signed-off-by: Chenghao Duan Reviewed-by: Pasha Tatashin --- mm/memfd_luo.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/memfd_luo.c b/mm/memfd_luo.c index 413df8c75c1d..5e5971f25c68 100644 --- a/mm/memfd_luo.c +++ b/mm/memfd_luo.c @@ -500,7 +500,7 @@ static int memfd_luo_retrieve(struct liveupdate_file_op= _args *args) } =20 vfs_setpos(file, ser->pos, MAX_LFS_FILESIZE); - file->f_inode->i_size =3D ser->size; + i_size_write(file_inode(file), ser->size); =20 if (ser->nr_folios) { folios_ser =3D kho_restore_vmalloc(&ser->folios); --=20 2.25.1