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]) by smtp.lore.kernel.org (Postfix) with ESMTP id 497A2C4167B for ; Wed, 13 Dec 2023 02:41:30 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9F6686B02F5; Tue, 12 Dec 2023 21:41:29 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 9A4D96B02F8; Tue, 12 Dec 2023 21:41:29 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 845DE6B02F9; Tue, 12 Dec 2023 21:41:29 -0500 (EST) 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 723076B02F5 for ; Tue, 12 Dec 2023 21:41:29 -0500 (EST) Received: from smtpin12.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 5042AA20BD for ; Wed, 13 Dec 2023 02:41:29 +0000 (UTC) X-FDA: 81560243898.12.27A4EC8 Received: from mail-oi1-f177.google.com (mail-oi1-f177.google.com [209.85.167.177]) by imf25.hostedemail.com (Postfix) with ESMTP id 8D491A001C for ; Wed, 13 Dec 2023 02:41:26 +0000 (UTC) Authentication-Results: imf25.hostedemail.com; dkim=pass header.d=bytedance.com header.s=google header.b=j1fOvIDL; spf=pass (imf25.hostedemail.com: domain of zhouchengming@bytedance.com designates 209.85.167.177 as permitted sender) smtp.mailfrom=zhouchengming@bytedance.com; dmarc=pass (policy=quarantine) header.from=bytedance.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1702435287; 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=Kx2ExU5Npip51Gk3K6Ffy4XYyqkPOYjVdErJoRrO4Uk=; b=yrWswEomkh1EsKGqghJO/4Mpja7xUncKG47WlOHphuV3sSJKxPNrE7cSxMmuY56oCexKDG JkuFNDPww7rb0sIuFU0BnwdiZUbxMZxidswfkv7aEjdrAMuwSK71rjKPoDCF7ncwkpKkUX r8RRFRbUwJF3jvfJQOw9cKeGuiMugeY= ARC-Authentication-Results: i=1; imf25.hostedemail.com; dkim=pass header.d=bytedance.com header.s=google header.b=j1fOvIDL; spf=pass (imf25.hostedemail.com: domain of zhouchengming@bytedance.com designates 209.85.167.177 as permitted sender) smtp.mailfrom=zhouchengming@bytedance.com; dmarc=pass (policy=quarantine) header.from=bytedance.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1702435287; a=rsa-sha256; cv=none; b=7Vm2G8ZzoXL98MurGHMdGrCzImpH1biNll2RuCl3Gg2EgjGJxVYkFpyIQmgQKYta4LB6QE C/Zkgjlmw/v7/PbhMCE5PH7g/vPcRCf0DWbK8HOm3es98tq8JlacS/auIN71JxY/DwbmnP 37kMGc2O5roVRqWStQ+AX3aQnQgXAqI= Received: by mail-oi1-f177.google.com with SMTP id 5614622812f47-3b9e2d50e61so4374105b6e.2 for ; Tue, 12 Dec 2023 18:41:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1702435285; x=1703040085; darn=kvack.org; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=Kx2ExU5Npip51Gk3K6Ffy4XYyqkPOYjVdErJoRrO4Uk=; b=j1fOvIDLHeftPvwJ3rXhNzzTvmn260C3anQRU2KWEAmWTNeSthKmQXYf5dDK9QZVVh 8yW0LEQyodaoFsstybdNMxckJpXpd4Z3jhWlCEy/fAlIFCeWgJxjEidx3UTZuanGAmUx uXeKljDuO1jzcwOEb4DcUEUgVDyu0LPQAp7rl1ndpsP/zMzk0xc3hPMmsK3WXRSQ9N3q lR0t3EE1KybnbC2U+iSFUgjkZ5FN1gIBfiYvVv8cKFKhVCz2sGFmRffVnNN3C83soLNk FNPgKd74qUVU4BIMm2hssbeJTMJmwtdqiGpOhF570AHPUNX+9Hi32W2vl74UzTqD/MYo L0QQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1702435285; x=1703040085; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=Kx2ExU5Npip51Gk3K6Ffy4XYyqkPOYjVdErJoRrO4Uk=; b=GELA8cRnvQPb/ca1OJrDhThrtMfPOkcP+6BrkeSWgBNZoVJAqRmEOKcRB8Dc2lPddx jMLSfMrptw443N2y9hPjF0MnvhlN2YtRXRiXSvqrSsgnBygJI2hYohX9frSLPLovjJg8 o41LzbIfF3OhkJIDhkmJ8IbiplIG/Q6i02IYNjuyV+P1qyMmALgr7WtVr8kdINJsRnsq zYEiFIPaEyG+XqvHaElF41A+tZr011EHd4Yi9y9VFSB9UC7ZVoHSjAKPvD/5WGQWKx2a XUIGgehEEa50A/gXFT/6QX5eM6bkFjERF6CFeiLbJwLch1kFM45CuftAx9HRxx4Xihun JS+g== X-Gm-Message-State: AOJu0YyG+Q8rFmWi4XCJD0HcFBZriagLnHAB4/roVRCJh+3gVU7LXgan Czum41DLqO/RPwSrfUNab0NUpQ== X-Google-Smtp-Source: AGHT+IE82iNT0eJz99u/vjA2FkaMkn7zxxDxr+jOWgF4pxSouIuDKu0rh+Fl/00w7zhtmqBshCauGA== X-Received: by 2002:a05:6808:201e:b0:3b9:ec87:849 with SMTP id q30-20020a056808201e00b003b9ec870849mr9041478oiw.74.1702435285282; Tue, 12 Dec 2023 18:41:25 -0800 (PST) Received: from [10.254.248.243] ([139.177.225.230]) by smtp.gmail.com with ESMTPSA id s16-20020a056a00195000b006cb574445efsm8890435pfk.88.2023.12.12.18.41.21 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 12 Dec 2023 18:41:24 -0800 (PST) Message-ID: <73c126cd-5a49-4040-96e2-d416da616158@bytedance.com> Date: Wed, 13 Dec 2023 10:41:17 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 3/7] mm/zswap: reuse dstmem when decompress Content-Language: en-US To: Nhat Pham Cc: Vitaly Wool , Johannes Weiner , Michal Hocko , Seth Jennings , Dan Streetman , Andrew Morton , Yosry Ahmed , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20231206-zswap-lock-optimize-v1-0-e25b059f9c3a@bytedance.com> <20231206-zswap-lock-optimize-v1-3-e25b059f9c3a@bytedance.com> From: Chengming Zhou In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 8D491A001C X-Rspam-User: X-Stat-Signature: 617d3y9kqt8ce59p146q566uyommi5im X-Rspamd-Server: rspam01 X-HE-Tag: 1702435286-671406 X-HE-Meta: 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 gWxv+TZG AdC906Cc7DiwBgpM12k+HDPEulThzIiIe9FneqaVwyrPc3XmSR7+vvzk20RydyNCXSocjvHh3QqqLygUFnvGI9RagUXXR5dHvcAJfUieslGa20d+qp5i8Gbcy7292Z1tBIqlb8PxW66ZtJDrZqvTsrIpBvTmXd8LxcvoQBOnzJNgfyFpnnFOsLHPTSgAU1zyTnWbHqMn+0jsoKRmJBz9a8sO2DcF4cEGmW0VrbX2zB4J7Q4gQ7OxnGtMBhVdAxsba+F4S3TfMY8xy6nn/dqD4jv8IKHvztwefl+2eOHa9X84oIQnQneDb2Zn+ZSk3zQ/sWm+QUAVuEx54hC5pvjdmGoJXOG1SPuiqbl2cvV03jgoAvB0oUzt+cqO4OwzqYNd6t/f8rhrPtPJUvX02NmHwLuse7tMzojv2O/OIJ4q3HvYEFVKP9jj4OXQUZXr6UQS5YzG4O7X1Zv0gJBTfva8AvsL1i5U7mnlvmo0O6HDNIW9Es6I= 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: On 2023/12/13 06:58, Nhat Pham wrote: > On Wed, Dec 6, 2023 at 1:46 AM Chengming Zhou > wrote: >> >> In the !zpool_can_sleep_mapped() case such as zsmalloc, we need to first >> copy the entry->handle memory to a temporary memory, which is allocated >> using kmalloc. >> >> Obviously we can reuse the per-compressor dstmem to avoid allocating >> every time, since it's percpu-compressor and protected in mutex. > > Ah this sounds like a good idea. We have to grab that mutex anyway - > might as well use the memory slot that is protected by that mutex. > >> >> Signed-off-by: Chengming Zhou >> --- >> mm/zswap.c | 29 +++++++++-------------------- >> 1 file changed, 9 insertions(+), 20 deletions(-) >> >> diff --git a/mm/zswap.c b/mm/zswap.c >> index a6b4859a0164..d93a7b58b5af 100644 >> --- a/mm/zswap.c >> +++ b/mm/zswap.c >> @@ -1758,9 +1758,9 @@ bool zswap_load(struct folio *folio) >> struct zswap_entry *entry; >> struct scatterlist input, output; >> struct crypto_acomp_ctx *acomp_ctx; >> - u8 *src, *dst, *tmp; >> + unsigned int dlen = PAGE_SIZE; >> + u8 *src, *dst; >> struct zpool *zpool; >> - unsigned int dlen; >> bool ret; >> >> VM_WARN_ON_ONCE(!folio_test_locked(folio)); >> @@ -1782,27 +1782,18 @@ bool zswap_load(struct folio *folio) >> goto stats; >> } >> >> - zpool = zswap_find_zpool(entry); >> - if (!zpool_can_sleep_mapped(zpool)) { >> - tmp = kmalloc(entry->length, GFP_KERNEL); >> - if (!tmp) { >> - ret = false; >> - goto freeentry; >> - } >> - } >> - >> /* decompress */ >> - dlen = PAGE_SIZE; >> - src = zpool_map_handle(zpool, entry->handle, ZPOOL_MM_RO); >> + acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); >> + mutex_lock(acomp_ctx->mutex); >> >> + zpool = zswap_find_zpool(entry); >> + src = zpool_map_handle(zpool, entry->handle, ZPOOL_MM_RO); >> if (!zpool_can_sleep_mapped(zpool)) { >> - memcpy(tmp, src, entry->length); >> - src = tmp; >> + memcpy(acomp_ctx->dstmem, src, entry->length); >> + src = acomp_ctx->dstmem; > > We're moving handle (un)mapping and the memory copying inside the > critical section protected by the mutex. Seems fine to me - > zswap_store() already did this IIUC. > >> zpool_unmap_handle(zpool, entry->handle); >> } >> >> - acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); >> - mutex_lock(acomp_ctx->mutex); >> sg_init_one(&input, src, entry->length); >> sg_init_table(&output, 1); >> sg_set_page(&output, page, PAGE_SIZE, 0); >> @@ -1813,15 +1804,13 @@ bool zswap_load(struct folio *folio) >> >> if (zpool_can_sleep_mapped(zpool)) >> zpool_unmap_handle(zpool, entry->handle); >> - else >> - kfree(tmp); >> >> ret = true; >> stats: >> count_vm_event(ZSWPIN); >> if (entry->objcg) >> count_objcg_event(entry->objcg, ZSWPIN); >> -freeentry: > > So it reduces the chance of zswap_load() failure due to unable to > memory allocation failure? Nice! > Yes, no need to allocate temporary memory anymore :) >> + >> spin_lock(&tree->lock); >> if (ret && zswap_exclusive_loads_enabled) { >> zswap_invalidate_entry(tree, entry); >> >> -- >> b4 0.10.1 > > Reviewed-by: Nhat Pham Thanks for review!