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=-18.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 7D384C433DB for ; Wed, 27 Jan 2021 16:42:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4602860187 for ; Wed, 27 Jan 2021 16:42:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231234AbhA0Qlu (ORCPT ); Wed, 27 Jan 2021 11:41:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44024 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232331AbhA0QkQ (ORCPT ); Wed, 27 Jan 2021 11:40:16 -0500 Received: from mail-ej1-x633.google.com (mail-ej1-x633.google.com [IPv6:2a00:1450:4864:20::633]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EFE32C061756 for ; Wed, 27 Jan 2021 08:40:00 -0800 (PST) Received: by mail-ej1-x633.google.com with SMTP id ox12so3585908ejb.2 for ; Wed, 27 Jan 2021 08:40:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kaishome.de; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=IiK5AvCudPzXIujDULruB+LT7FuiTYYEQPJhO7d/8+I=; b=FEliTycEfqDvS3n9Yb/i2SbDTtpvTIEcCqPqdcNej5+M6Ahh+zlXxbcwHtC+nTdBUQ hZnQpUzAOcYUXkMnoWfXnMW3M1XIMkC0QeUE9Rrn82X0obzM/3rxJ51gvhJP1+7j1sr/ CF++Bs4s5Ta/avZgoYk7GQ8gRiJKMZ5CJfauM= 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:in-reply-to :references:mime-version:content-transfer-encoding; bh=IiK5AvCudPzXIujDULruB+LT7FuiTYYEQPJhO7d/8+I=; b=fn+b9rlb+gIrXek+XWPRoMoZth+hizLqRXIgT+ESXKtTH9l7g2gArVC6LbR+lZf98J OWSr5X7zE7kbswC8JstHetkIBsumRHS89xlM6xuVru059ZzxiBBugouuaHs4U5h7JsR4 8IkWuFlx+G01wwNOIVKSSUlaQ2vEXEkVa+sqlkz4tHFUQiZ4xaS/601SbMf1Ppoovhyb 61eifznfNQ9SIw/o+AOsIXaVOSgzsWCWfwFeyCXLx0vGxa8Lq+C+UAL73PM+7Oi1SrCW IaOsavC3Sx29IcNFZ9LzihVhHYI7Abxj/9qSYlLyoOrWmhgpzvQ2zYiHdY09AZeMxFfj 6/JA== X-Gm-Message-State: AOAM533mxO/fwcCOXOijJ6gpoWqQuSal99hNlUNbw6rjKVDn6p+ukahz 0Eo9D6/XR7FGa6xMF/kvIPrDLjosbMwtxA== X-Google-Smtp-Source: ABdhPJzDo6HFEmd7yGjtF92SX+vxr3X5wixIuOWmdn8fyJhe/lU3wG8VKaTq6Y/Hn9Vb+Rhkz7Fqrw== X-Received: by 2002:a17:906:5e4c:: with SMTP id b12mr7544938eju.297.1611765599297; Wed, 27 Jan 2021 08:39:59 -0800 (PST) Received: from jupiter.sol.kaishome.de ([2a02:8109:c40:9200::1a2]) by smtp.gmail.com with ESMTPSA id w12sm1584013edr.29.2021.01.27.08.39.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 27 Jan 2021 08:39:58 -0800 (PST) Received: (nullmailer pid 593511 invoked by uid 500); Wed, 27 Jan 2021 16:39:57 -0000 From: Kai Krakow To: linux-bcache@vger.kernel.org Cc: Kai Krakow , Coly Li Subject: [PATCH 1/2] Revert "bcache: Kill btree_io_wq" Date: Wed, 27 Jan 2021 17:39:46 +0100 Message-Id: <20210127163947.593460-1-kai@kaishome.de> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210127132350.557935-1-kai@kaishome.de> References: <20210127132350.557935-1-kai@kaishome.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-bcache@vger.kernel.org This reverts commit 56b30770b27d54d68ad51eccc6d888282b568cee. With the btree using the system_wq, I seem to see a lot more desktop latency than I should. After some more investigation, it looks like the original assumption of 56b3077 no longer is true, and bcache has a very high potential of congesting the system_wq. In turn, this introduces laggy desktop performance, IO stalls (at least with btrfs), and input events may be delayed. So let's revert this. Cc: Coly Li Signed-off-by: Kai Krakow --- drivers/md/bcache/bcache.h | 2 ++ drivers/md/bcache/btree.c | 21 +++++++++++++++++++-- drivers/md/bcache/super.c | 4 ++++ 3 files changed, 25 insertions(+), 2 deletions(-) diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h index 1d57f48307e66..b1ed16c7a5341 100644 --- a/drivers/md/bcache/bcache.h +++ b/drivers/md/bcache/bcache.h @@ -1042,5 +1042,7 @@ void bch_debug_exit(void); void bch_debug_init(void); void bch_request_exit(void); int bch_request_init(void); +void bch_btree_exit(void); +int bch_btree_init(void); #endif /* _BCACHE_H */ diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c index 910df242c83df..952f022db5a5f 100644 --- a/drivers/md/bcache/btree.c +++ b/drivers/md/bcache/btree.c @@ -99,6 +99,8 @@ #define PTR_HASH(c, k) \ (((k)->ptr[0] >> c->bucket_bits) | PTR_GEN(k, 0)) +static struct workqueue_struct *btree_io_wq; + #define insert_lock(s, b) ((b)->level <= (s)->lock) @@ -308,7 +310,7 @@ static void __btree_node_write_done(struct closure *cl) btree_complete_write(b, w); if (btree_node_dirty(b)) - schedule_delayed_work(&b->work, 30 * HZ); + queue_delayed_work(btree_io_wq, &b->work, 30 * HZ); closure_return_with_destructor(cl, btree_node_write_unlock); } @@ -481,7 +483,7 @@ static void bch_btree_leaf_dirty(struct btree *b, atomic_t *journal_ref) BUG_ON(!i->keys); if (!btree_node_dirty(b)) - schedule_delayed_work(&b->work, 30 * HZ); + queue_delayed_work(btree_io_wq, &b->work, 30 * HZ); set_btree_node_dirty(b); @@ -2764,3 +2766,18 @@ void bch_keybuf_init(struct keybuf *buf) spin_lock_init(&buf->lock); array_allocator_init(&buf->freelist); } + +void bch_btree_exit(void) +{ + if (btree_io_wq) + destroy_workqueue(btree_io_wq); +} + +int __init bch_btree_init(void) +{ + btree_io_wq = create_singlethread_workqueue("bch_btree_io"); + if (!btree_io_wq) + return -ENOMEM; + + return 0; +} diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index 2047a9cccdb5d..dc4fe7eeda815 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -2815,6 +2815,7 @@ static void bcache_exit(void) { bch_debug_exit(); bch_request_exit(); + bch_btree_exit(); if (bcache_kobj) kobject_put(bcache_kobj); if (bcache_wq) @@ -2880,6 +2881,9 @@ static int __init bcache_init(void) if (!bcache_wq) goto err; + if (bch_btree_init()) + goto err; + bch_journal_wq = alloc_workqueue("bch_journal", WQ_MEM_RECLAIM, 0); if (!bch_journal_wq) goto err; -- 2.26.2