From nobody Wed Dec 17 14:39:10 2025 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) (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 96B731CF5EA for ; Thu, 10 Oct 2024 17:52:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.180.131 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728582751; cv=none; b=i/8FWf9gcvLEbI3LFiGCt4iNdEiwjzPyIe9ByyoXop1xUM7yd58ePVj0A+d29CG+D3qb7PfNjuUViuXWXFcHr4Pi/rQFo6b3WSvamVdUvIrwegEqzsMxnvQ/mjCkjm4DbzqCqh7yWius2w99SP1h4hEp6MpZzOrS7/vMe+xL7q4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728582751; c=relaxed/simple; bh=wIJkzro5qJWOdr2gzKdknWXZ5j3M5dSu0NXfBW2TRxM=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=aF4Lsvwhct5O8oSY2TXosheVgP8IJps/l70CaF5Z7kZIP7rR/WMyvhO5C//zNr5jZt8XhSfLWw4w76UYZggFzjd/0Rif9r89Gl9M8K9lodPkn4y3MNOJ1D/ykBL1Mq/UOounce/9qrP2fn3vX812feGxOHBhZy/RwyvIYchVsSQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=quicinc.com; spf=pass smtp.mailfrom=quicinc.com; dkim=pass (2048-bit key) header.d=quicinc.com header.i=@quicinc.com header.b=jMBof341; arc=none smtp.client-ip=205.220.180.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=quicinc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=quicinc.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=quicinc.com header.i=@quicinc.com header.b="jMBof341" Received: from pps.filterd (m0279872.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 49AD8kOC027035; Thu, 10 Oct 2024 17:52:12 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h= cc:content-type:date:from:message-id:mime-version:subject:to; s= qcppdkim1; bh=oNl8qbJwfIXDG/UAwjT6ZFo0a8CuYyPXXz44Avl05qc=; b=jM Bof341BFv4s5/sMJr0NfS9JQv/gHer+u90f8QNg4JVFo/cge/lvIvcgaWzTaNVxs uPrc2evx8QN8p2t1r05luUrt2Fu2ikLWqTW9oKKIIVYtv1WL4wLagsdzHyaiTpNM si5q1IxkDOxQE9SbfGh8hKaWsentIVfbsvRjf8xNsieK2WA6HiV1FCNXArQdaju1 qrlqeor9Iu7cu5Bpji1sb3NwUl58fuKPSI9hCTpK5vTVcrmS2gArFLO8ieec7WYy Xgub/n6MGl6RwvktekzxHVHxHi9QZNVDagGhkOXnOyyPRH2rOglwO+l9l1TKBGvh j0xSRwC3yCCKJN8xqrEg== Received: from nasanppmta02.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 426fj6rqyc-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 10 Oct 2024 17:52:12 +0000 (GMT) Received: from nasanex01a.na.qualcomm.com (nasanex01a.na.qualcomm.com [10.52.223.231]) by NASANPPMTA02.qualcomm.com (8.18.1.2/8.18.1.2) with ESMTPS id 49AHqBcx011580 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 10 Oct 2024 17:52:11 GMT Received: from hu-pintu-blr.qualcomm.com (10.80.80.8) by nasanex01a.na.qualcomm.com (10.52.223.231) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.9; Thu, 10 Oct 2024 10:52:07 -0700 From: Pintu Kumar To: , , , , , CC: , , , Pintu Kumar Subject: [PATCH] mm/zsmalloc: Use memcpy_from/to_page whereever possible Date: Thu, 10 Oct 2024 23:21:43 +0530 Message-ID: <20241010175143.27262-1-quic_pintu@quicinc.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: nasanex01b.na.qualcomm.com (10.46.141.250) To nasanex01a.na.qualcomm.com (10.52.223.231) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-GUID: fqU7cb6IRHNjToMAf-LH-u0MmQNgoe0x X-Proofpoint-ORIG-GUID: fqU7cb6IRHNjToMAf-LH-u0MmQNgoe0x X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1039,Hydra:6.0.680,FMLib:17.12.60.29 definitions=2024-09-06_09,2024-09-06_01,2024-09-02_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 bulkscore=0 mlxlogscore=796 lowpriorityscore=0 spamscore=0 malwarescore=0 adultscore=0 suspectscore=0 clxscore=1011 mlxscore=0 impostorscore=0 priorityscore=1501 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2409260000 definitions=main-2410100118 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" As part of [1] we have replaced kmap/kunmap_atomic() with kmap_local_page()/kunmap_local(). But later it was found that some of the code could be replaced with already available apis in highmem.h, such as memcpy_from_page()/memcpy_to_page(). Also, update the comments with correct api naming. [1] https://lkml.kernel.org/r/20241001175358.12970-1-quic_pintu@quicinc.com Signed-off-by: Pintu Kumar Suggested-by: Matthew Wilcox Suggested-by: Sergey Senozhatsky --- mm/zsmalloc.c | 36 +++++++++++++----------------------- 1 file changed, 13 insertions(+), 23 deletions(-) diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index d3ff10160a5f..64b66a4d3e6e 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -263,7 +263,7 @@ struct zspage { struct mapping_area { local_lock_t lock; char *vm_buf; /* copy buffer for objects that span pages */ - char *vm_addr; /* address of kmap_atomic()'ed pages */ + char *vm_addr; /* address of kmap_local_page()'ed pages */ enum zs_mapmode vm_mm; /* mapping mode */ }; =20 @@ -1046,11 +1046,10 @@ static inline void __zs_cpu_down(struct mapping_are= a *area) static void *__zs_map_object(struct mapping_area *area, struct page *pages[2], int off, int size) { - int sizes[2]; - void *addr; + size_t sizes[2]; char *buf =3D area->vm_buf; =20 - /* disable page faults to match kmap_atomic() return conditions */ + /* disable page faults to match kmap_local_page() return conditions */ pagefault_disable(); =20 /* no read fastpath */ @@ -1061,12 +1060,8 @@ static void *__zs_map_object(struct mapping_area *ar= ea, sizes[1] =3D size - sizes[0]; =20 /* copy object to per-cpu buffer */ - addr =3D kmap_local_page(pages[0]); - memcpy(buf, addr + off, sizes[0]); - kunmap_local(addr); - addr =3D kmap_local_page(pages[1]); - memcpy(buf + sizes[0], addr, sizes[1]); - kunmap_local(addr); + memcpy_from_page(buf, pages[0], off, sizes[0]); + memcpy_from_page(buf + sizes[0], pages[1], 0, sizes[1]); out: return area->vm_buf; } @@ -1074,8 +1069,7 @@ static void *__zs_map_object(struct mapping_area *are= a, static void __zs_unmap_object(struct mapping_area *area, struct page *pages[2], int off, int size) { - int sizes[2]; - void *addr; + size_t sizes[2]; char *buf; =20 /* no write fastpath */ @@ -1091,15 +1085,11 @@ static void __zs_unmap_object(struct mapping_area *= area, sizes[1] =3D size - sizes[0]; =20 /* copy per-cpu buffer to object */ - addr =3D kmap_local_page(pages[0]); - memcpy(addr + off, buf, sizes[0]); - kunmap_local(addr); - addr =3D kmap_local_page(pages[1]); - memcpy(addr, buf + sizes[0], sizes[1]); - kunmap_local(addr); + memcpy_to_page(pages[0], off, buf, sizes[0]); + memcpy_to_page(pages[1], 0, buf + sizes[0], sizes[1]); =20 out: - /* enable page faults to match kunmap_atomic() return conditions */ + /* enable page faults to match kunmap_local() return conditions */ pagefault_enable(); } =20 @@ -1511,10 +1501,10 @@ static void zs_object_copy(struct size_class *class= , unsigned long dst, d_size -=3D size; =20 /* - * Calling kunmap_atomic(d_addr) is necessary. kunmap_atomic() - * calls must occurs in reverse order of calls to kmap_atomic(). - * So, to call kunmap_atomic(s_addr) we should first call - * kunmap_atomic(d_addr). For more details see + * Calling kunmap_local(d_addr) is necessary. kunmap_local() + * calls must occurs in reverse order of calls to kmap_local_page(). + * So, to call kunmap_local(s_addr) we should first call + * kunmap_local(d_addr). For more details see * Documentation/mm/highmem.rst. */ if (s_off >=3D PAGE_SIZE) { --=20 2.17.1