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 X-Spam-Level: X-Spam-Status: No, score=-13.5 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 36D81C43462 for ; Fri, 9 Apr 2021 07:17:32 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 93C1D61177 for ; Fri, 9 Apr 2021 07:17:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 93C1D61177 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 185146B006E; Fri, 9 Apr 2021 03:17:31 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 10C286B0070; Fri, 9 Apr 2021 03:17:31 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D92C36B0071; Fri, 9 Apr 2021 03:17:30 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0162.hostedemail.com [216.40.44.162]) by kanga.kvack.org (Postfix) with ESMTP id B75156B006E for ; Fri, 9 Apr 2021 03:17:30 -0400 (EDT) Received: from smtpin09.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 7CED71830EE7D for ; Fri, 9 Apr 2021 07:17:30 +0000 (UTC) X-FDA: 78011973060.09.7D6BC3F Received: from mail-ej1-f52.google.com (mail-ej1-f52.google.com [209.85.218.52]) by imf23.hostedemail.com (Postfix) with ESMTP id CBB17A0003A0 for ; Fri, 9 Apr 2021 07:17:28 +0000 (UTC) Received: by mail-ej1-f52.google.com with SMTP id u17so7065005ejk.2 for ; Fri, 09 Apr 2021 00:17:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=MAgKFkUbajfTwkiBbjHCwLbY8LqpQ8PBmh7VA/cwU0E=; b=igEspD4oLTpM4o2jCwSGcYwjzgvaFDiBYrZde/yigoCOzASZ6Q36kFdOLTPk9+sEKA At9Rg6okYKLJenOHCVlutmLzuLAhyDZfgGBYJ66Oj8C6MPsS8wita034AoWkMFIgC25Z 7hsoj7iGl8V5wzeL/wT3tqHTfrZTHkZwk5UBViKyHTywBmZFq0frm8mI3J2xlddZBmoE s8q8GSI2WepiZ10MAzwDGwDMtYCoPpkyTnDhEtIa1GyGDEw6k37Rs+HJ9yff6WL6sw1O 4WqcJX+pPtmQilHkwSI8hffyk+1BcLWllcyd2nRmfoTOw/Abay7/0UE6y0hP+L+s4Qlb YxuQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=MAgKFkUbajfTwkiBbjHCwLbY8LqpQ8PBmh7VA/cwU0E=; b=AArSiaZ9geZ0P7m9kkRJNNw1gGNjbEGbAP6EDXtoiGRcCuymWOSCcAOe0cGknmgvpH xTyrq78R9V4js1Jg3g07iyAyf9TJC0fknsDIuWlaHUSdXW8g/IYPF8aAEhoygGPhBynn 3wkgNaeF1PlpD7FjYjvyFc0BaLh5nralz1uB5rHPIh77Mzz3lB7trz8Sb9ih79AmeGZA Nmq9LeXkGAi2L9eAXJMiBDeyzyQiL3YUSRCgRVBmzSoUxWhNtRsIsQLSGuyCV9P7bt5o FDC9fhqYprazNUpHMKKm/N8etW6xMHxl73TuUY+W+XlYu3Bx3wOlBz84ZfzP6VMUOUIm FKow== X-Gm-Message-State: AOAM532RsZaR9tTRvB/Dk/xJQXlB2Fw5BVborsmmr5JNqtYJJKrWlPyj 3jmxSsgnmpWBpiBU1m8AGew= X-Google-Smtp-Source: ABdhPJzQ2tCFOmAsi20Gal6ccZzgbiWTy3xs28H9Fe7zY+J/NCEjtr1WZzzVEoA6J7yNPFrn15rtkw== X-Received: by 2002:a17:906:5618:: with SMTP id f24mr15226911ejq.414.1617952646960; Fri, 09 Apr 2021 00:17:26 -0700 (PDT) Received: from abel.fritz.box ([2a02:908:1252:fb60:216f:9340:7a2b:4f98]) by smtp.gmail.com with ESMTPSA id w1sm905369edt.89.2021.04.09.00.17.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 09 Apr 2021 00:17:26 -0700 (PDT) From: "=?UTF-8?q?Christian=20K=C3=B6nig?=" X-Google-Original-From: =?UTF-8?q?Christian=20K=C3=B6nig?= To: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: ray.huang@amd.com, daniel@ffwll.ch, akpm@linux-foundation.org Subject: [PATCH 1/2] mm/vmscan: add sync_shrinkers function Date: Fri, 9 Apr 2021 09:17:24 +0200 Message-Id: <20210409071725.1532-1-christian.koenig@amd.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-Stat-Signature: nbrd87m734d5o8gqz45sm45s3tzwcj5r X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: CBB17A0003A0 Received-SPF: none (gmail.com>: No applicable sender policy available) receiver=imf23; identity=mailfrom; envelope-from=""; helo=mail-ej1-f52.google.com; client-ip=209.85.218.52 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1617952648-268764 Content-Transfer-Encoding: quoted-printable 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: To be able to switch to a spinlock and reduce lock contention in the TTM shrinker we don't want to hold a mutex while unmapping and freeing pages from the pool. But then we somehow need to prevent a race between (for example) the shri= nker trying to free pages and hotplug trying to remove the device which those = pages belong to. Taking and releasing the shrinker semaphore on the write side after unmapping and freeing all pages should make sure that no shrinker is runn= ing in paralell any more. Signed-off-by: Christian K=C3=B6nig --- include/linux/shrinker.h | 1 + mm/vmscan.c | 10 ++++++++++ 2 files changed, 11 insertions(+) diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h index 0f80123650e2..6b75dc372fce 100644 --- a/include/linux/shrinker.h +++ b/include/linux/shrinker.h @@ -92,4 +92,5 @@ extern void register_shrinker_prepared(struct shrinker = *shrinker); extern int register_shrinker(struct shrinker *shrinker); extern void unregister_shrinker(struct shrinker *shrinker); extern void free_prealloced_shrinker(struct shrinker *shrinker); +extern void sync_shrinkers(void); #endif diff --git a/mm/vmscan.c b/mm/vmscan.c index 562e87cbd7a1..46cd9c215d73 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -408,6 +408,16 @@ void unregister_shrinker(struct shrinker *shrinker) } EXPORT_SYMBOL(unregister_shrinker); =20 +/** + * sync_shrinker - Wait for all running shrinkers to complete. + */ +void sync_shrinkers(void) +{ + down_write(&shrinker_rwsem); + up_write(&shrinker_rwsem); +} +EXPORT_SYMBOL(sync_shrinkers); + #define SHRINK_BATCH 128 =20 static unsigned long do_shrink_slab(struct shrink_control *shrinkctl, --=20 2.25.1