From patchwork Fri Jul 5 12:49:14 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sebastian Andrzej Siewior X-Patchwork-Id: 13725065 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 86AC81E867; Fri, 5 Jul 2024 12:51:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720183864; cv=none; b=cjR51YiYeDvcPFiWRu4l7i8lz9HbBFal22Ml4XfR0AUYr/lnYIJ/cvo1woCcuVXJcMiD/I2rIVg3h1YDAbheYZMmcxGs+MUBriKmxmj9L5B/rWvKUCsFeBs0FKGZpMgbM1QNKmPNMiUC3QpQbbR076BIXsBUulhvbKrW9uqAzMA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720183864; c=relaxed/simple; bh=k71QRPmSseA5MCLgBwvhkMDWTpuFZICNWc1N3USp+9I=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Q9nwRkh7ocaJSm8THXKVMnLLEoirmMg7fO89b/6d2fsonSu9VUwL63fAb7mrB24DbJdlCgrhf333hmxFXlvyq+gDxoGAn4TurQOpWdoDHc5IHtcstJ7DpMFqRpfyn6B9PlPdTIY8G/gw9ywP8nHH+zCmMZpDHWb/ShfZXbIUAJU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=3Lh1PBAs; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=HHrSQufw; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="3Lh1PBAs"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="HHrSQufw" From: Sebastian Andrzej Siewior DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1720183861; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=SdUrf3Hy2C34gl1jMZkbRbR9ItFYBrR+sH8mMQClkz4=; b=3Lh1PBAs1KQUkvSVdgAnshIcgNXY3ZXbt0HlfUH74Va7RBk7TA/HdqfAAesULro2A9svql DzAu+EkOM+/xrf+hBzxKnLSAUdcz0zV3Xgrs5Q/KwfEo3RYFBMlAFCD+KUFHAd/sF159ON NDgGxSlSrb54/M81eE0rxTL++3SI/4SpFdPAKHV2qaXDVfTeiSSgnq/SM5fXN/BUTnZlst g+TyI/7M6WpRYJ/GqAMebUb1Kecn73FKdMbl9XEayl6NUmrl4ZFuk3XhWySCT8QbS02gM9 ubzA4/dOh4pIP8/fDBx2y3lAUb2kF6ouPokxcuA9IdbEGI8ULQrR1xtmV/qkew== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1720183861; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=SdUrf3Hy2C34gl1jMZkbRbR9ItFYBrR+sH8mMQClkz4=; b=HHrSQufwqCEvgf3s77nlhkCBKa8qcQtCUB14NFbQIOzuIZGfN5TeddGqQu3WUNYIjgFE3O wVqT4gXrACulkvAQ== To: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Jens Axboe , Mike Galbraith , Minchan Kim , Sergey Senozhatsky , Thomas Gleixner , Alexander Lobakin , Sebastian Andrzej Siewior Subject: [PATCH v3 1/3] zram: Replace bit spinlocks with a spinlock_t. Date: Fri, 5 Jul 2024 14:49:14 +0200 Message-ID: <20240705125058.1564001-2-bigeasy@linutronix.de> In-Reply-To: <20240705125058.1564001-1-bigeasy@linutronix.de> References: <20240705125058.1564001-1-bigeasy@linutronix.de> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Mike Galbraith The bit spinlock disables preemption. The spinlock_t lock becomes a sleeping lock on PREEMPT_RT and it can not be acquired in this context. In this locked section, zs_free() acquires a zs_pool::lock, and there is access to zram::wb_limit_lock. Add a spinlock_t for locking. Keep the set/ clear ZRAM_LOCK bit after the lock has been acquired/ dropped. The size of struct zram_table_entry increases by 4 bytes due to lock and additional 4 bytes padding with CONFIG_ZRAM_TRACK_ENTRY_ACTIME enabled. Signed-off-by: Mike Galbraith Reviewed-by: Sergey Senozhatsky Signed-off-by: Sebastian Andrzej Siewior --- drivers/block/zram/zram_drv.c | 20 +++++++++++++++++--- drivers/block/zram/zram_drv.h | 1 + 2 files changed, 18 insertions(+), 3 deletions(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 3acd7006ad2cc..72006e6e34883 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -57,19 +57,32 @@ static void zram_free_page(struct zram *zram, size_t index); static int zram_read_page(struct zram *zram, struct page *page, u32 index, struct bio *parent); +static void zram_meta_init_table_locks(struct zram *zram, size_t num_pages) +{ + for (size_t index = 0; index < num_pages; index++) + spin_lock_init(&zram->table[index].lock); +} + static int zram_slot_trylock(struct zram *zram, u32 index) { - return bit_spin_trylock(ZRAM_LOCK, &zram->table[index].flags); + int ret; + + ret = spin_trylock(&zram->table[index].lock); + if (ret) + __set_bit(ZRAM_LOCK, &zram->table[index].flags); + return ret; } static void zram_slot_lock(struct zram *zram, u32 index) { - bit_spin_lock(ZRAM_LOCK, &zram->table[index].flags); + spin_lock(&zram->table[index].lock); + __set_bit(ZRAM_LOCK, &zram->table[index].flags); } static void zram_slot_unlock(struct zram *zram, u32 index) { - bit_spin_unlock(ZRAM_LOCK, &zram->table[index].flags); + __clear_bit(ZRAM_LOCK, &zram->table[index].flags); + spin_unlock(&zram->table[index].lock); } static inline bool init_done(struct zram *zram) @@ -1226,6 +1239,7 @@ static bool zram_meta_alloc(struct zram *zram, u64 disksize) if (!huge_class_size) huge_class_size = zs_huge_class_size(zram->mem_pool); + zram_meta_init_table_locks(zram, num_pages); return true; } diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h index 35e3221446292..dcc3c106ce713 100644 --- a/drivers/block/zram/zram_drv.h +++ b/drivers/block/zram/zram_drv.h @@ -69,6 +69,7 @@ struct zram_table_entry { unsigned long element; }; unsigned long flags; + spinlock_t lock; #ifdef CONFIG_ZRAM_TRACK_ENTRY_ACTIME ktime_t ac_time; #endif