From patchwork Thu Jun 20 15:28:50 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: 13705724 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 66EEA1AF6B4; Thu, 20 Jun 2024 15:36:10 +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=1718897772; cv=none; b=ap7SNIeE+Hc6E7uC/q0Hf3CjaHc8qpQn7Z5C8SLEtNnsfXh3NR4oZagpKJ7W1/LPrfsug1oyIrHIIGg9v0Eo5yrQnbWLJtfF36Whxv033xlXFIM11VY7pN1QoB/NbpZXoS7a6epIvrhxAG3eX1wUobzBJkmX5d0h9J/QSkhKVnw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718897772; c=relaxed/simple; bh=YXyPcSBPlpPYufm75AgrQX5YC6L7hQSvZGAXUKH6HcE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=F+qAF3mVlkMGFGttFCI76H9dibZGBxf8UcDb2/5cIkZ/U+ucOKEZKKiOIFO4oRPkaUDbRR2clwIJv39BHvvkDLhwlQRkUMLGWHoC+7+vFr8IXWfP3z/P8Obe6dmbkKIscFQ/5PLDaDhid4zQm4OlZXq62Cp+5GkhKGKi36Ce39c= 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=o/OhD4d2; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=8Yr5fxfn; 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="o/OhD4d2"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="8Yr5fxfn" From: Sebastian Andrzej Siewior DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1718897763; 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=KBOAfjSISfflCVpyoflTryup4k2GWDjwHCEfQlVKqA8=; b=o/OhD4d2v+WnYbUIGTQasO5G/81YDg0/TURU4xqeJC1fNvptJurNyUENMmn47IkmtZ5K2g zZ3e74sRCwq+jsb/KmF0AuRF99PsAu/Hc1p1A6Xp0lh6fhAEnfumtWkbaAhRAdZImS2MN9 8hPs8phZGua2OyN9DON40Uq/AclssIU4qY4n+1diIGIv0t/RV5d7JZu15/gutUeAY0LURE X28JgdvzEQxOVwL9mmD71EWJiOQPvMLiJGCZTANuOTBdI1lWXyhhfmik2rx06cDi438w37 1OkYza/rAVmwUazENSu5/L5ITBBuQ/DXGtZHDNyG29qdJyPdYuf77g8iJFgbfw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1718897763; 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=KBOAfjSISfflCVpyoflTryup4k2GWDjwHCEfQlVKqA8=; b=8Yr5fxfn5M04DM2f1g4w1W9pvc5hv9AfEarzbPSzxfmp6HCy4T0NuKOxT+ts4Wd5BOV8gk xYbJQw8uL5/nbUBw== To: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Minchan Kim , Sergey Senozhatsky , Jens Axboe , Thomas Gleixner , Mike Galbraith , Sebastian Andrzej Siewior Subject: [PATCH v2 1/3] zram: Replace bit spinlocks with a spinlock_t. Date: Thu, 20 Jun 2024 17:28:50 +0200 Message-ID: <20240620153556.777272-2-bigeasy@linutronix.de> In-Reply-To: <20240620153556.777272-1-bigeasy@linutronix.de> References: <20240620153556.777272-1-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 Signed-off-by: Sebastian Andrzej Siewior --- drivers/block/zram/zram_drv.c | 22 +++++++++++++++++++--- drivers/block/zram/zram_drv.h | 1 + 2 files changed, 20 insertions(+), 3 deletions(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 3acd7006ad2cc..036845cd4f25e 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -57,19 +57,34 @@ 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) +{ + size_t index; + + for (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 +1241,7 @@ 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 From patchwork Thu Jun 20 15:28:51 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: 13705725 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 5A2661AF6B5; Thu, 20 Jun 2024 15:36:11 +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=1718897772; cv=none; b=ixGYQp9QJdWCNJdnbUWy43LFfLEbfNdb8eXH3K3rbPdTVR9YQnLyxFVLBoQma8Lptj8hOAvclk2GP6Rk5tU72ahMAJbJBWJ7mJrUnXaDVNx1HxNjUUA9lB0O8veKlHSO5uSiPCmUDQBtCAbHvrPbEnkIM0vLM34JE4vnZkbuFNk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718897772; 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dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="ufAIY1wh" From: Sebastian Andrzej Siewior DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1718897763; 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=lSUO1Lfh9dmWaOWg+yhEGkMIzbQkGi2VLM4kJm3yKcA=; b=gVPjjknMrRrMAjEozcQKij6eTWy2UxrJxWWQTja90GklIjM5JXmOjJIhcOUWRt62lK6/Cy ELP5wvnAJ5VSkyfotjM0PNBWwLfxl1k3NSHmIbyV000lUIofAV6322Bf8j2H0LLP5MOdGq agLJG9Y1dhdoJ7bmSCsoX56fon7u2aNNatnwMPxxC/jKvg94J3saY/NtWR8n0f4anOsVKJ 35jJ+UDSKQj+N5GIQi8b2dI210tNCIMX87M8GgRyDx8PXXwq3hp80IfAk75cSPT7zxdq57 BjVPksx3WQKLQ9aPSJmB/HBZ59MN1SuolwOI3zz6cDAHy1rn8rZKKoO4r5nT9w== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1718897763; 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=lSUO1Lfh9dmWaOWg+yhEGkMIzbQkGi2VLM4kJm3yKcA=; b=ufAIY1whRVAoSCt55InORVfOHSm4rD2CGSwXc2aqXiPCwY2n1FTG7eTzZgD4kr04z1XkXr 6I8Xo3fYw1Wh+IAg== To: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Minchan Kim , Sergey Senozhatsky , Jens Axboe , Thomas Gleixner , Mike Galbraith , Sebastian Andrzej Siewior Subject: [PATCH v2 2/3] zram: Remove ZRAM_LOCK Date: Thu, 20 Jun 2024 17:28:51 +0200 Message-ID: <20240620153556.777272-3-bigeasy@linutronix.de> In-Reply-To: <20240620153556.777272-1-bigeasy@linutronix.de> References: <20240620153556.777272-1-bigeasy@linutronix.de> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 The ZRAM_LOCK was used for locking and after the addition of spinlock_t the bit set and cleared but there no reader of it. Remove the ZRAM_LOCK bit. Signed-off-by: Sebastian Andrzej Siewior --- drivers/block/zram/zram_drv.c | 11 ++--------- drivers/block/zram/zram_drv.h | 4 +--- 2 files changed, 3 insertions(+), 12 deletions(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 036845cd4f25e..659966e00c300 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -67,23 +67,16 @@ static void zram_meta_init_table_locks(struct zram *zram, size_t num_pages) static int zram_slot_trylock(struct zram *zram, u32 index) { - int ret; - - ret = spin_trylock(&zram->table[index].lock); - if (ret) - __set_bit(ZRAM_LOCK, &zram->table[index].flags); - return ret; + return spin_trylock(&zram->table[index].lock); } static void zram_slot_lock(struct zram *zram, u32 index) { spin_lock(&zram->table[index].lock); - __set_bit(ZRAM_LOCK, &zram->table[index].flags); } static void zram_slot_unlock(struct zram *zram, u32 index) { - __clear_bit(ZRAM_LOCK, &zram->table[index].flags); spin_unlock(&zram->table[index].lock); } @@ -1299,7 +1292,7 @@ static void zram_free_page(struct zram *zram, size_t index) zram_set_handle(zram, index, 0); zram_set_obj_size(zram, index, 0); WARN_ON_ONCE(zram->table[index].flags & - ~(1UL << ZRAM_LOCK | 1UL << ZRAM_UNDER_WB)); + ~(1UL << ZRAM_UNDER_WB)); } /* diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h index dcc3c106ce713..262fa960a0783 100644 --- a/drivers/block/zram/zram_drv.h +++ b/drivers/block/zram/zram_drv.h @@ -45,9 +45,7 @@ /* Flags for zram pages (table[page_no].flags) */ enum zram_pageflags { - /* zram slot is locked */ - ZRAM_LOCK = ZRAM_FLAG_SHIFT, - ZRAM_SAME, /* Page consists the same element */ + ZRAM_SAME = ZRAM_FLAG_SHIFT, /* Page consists the same element */ ZRAM_WB, /* page is stored on backing_device */ ZRAM_UNDER_WB, /* page is under writeback */ ZRAM_HUGE, /* Incompressible page */ From patchwork Thu Jun 20 15:28:52 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: 13705726 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 A1B791AF697; 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dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=a5ejUb4N; 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="kil7NbsQ"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="a5ejUb4N" From: Sebastian Andrzej Siewior DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1718897763; 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=KXGSH918z06aphcGtDz/mGBYt1ti++St5iUsrCgtWaU=; b=kil7NbsQH7jdwnMwRQ2mC2ylka48gdZL9tpAv4FRBrjvfMadVogEM1/+WTiQ5+0827VZYf c87nD8aISnp4+va3ls/l3QT4JUHUmDGdZ1asJOWL4kPFTTnTJRVP5Q2pRkALWgamO1+Bn8 Y1fTlTo5oicQavQkXt1U/Fb+N+fTagGTI6/BWxaW9iIYjlYZG3iR5PmTDJPTWI2bapYfnN 6/I1GWEVy59eJYLHRjt4BUifRIWL9g4077CT2sMjFnpEE+9s/GMWbp572xsNjbd6myuUEk PtVtO85IRdsD7oxfcX2ZOVNgVrryj5061zRuWhrX9hEHVyCYCtMknXO0qgM5DQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1718897763; 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=KXGSH918z06aphcGtDz/mGBYt1ti++St5iUsrCgtWaU=; b=a5ejUb4NDgy+H/Z5dRXG/oqwib78j7B/Vohrw7KQ3ygD0UP4FgUax97LjpcaGMfAOiPRLp 4bsmjqshnDFWC0Dg== To: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Minchan Kim , Sergey Senozhatsky , Jens Axboe , Thomas Gleixner , Mike Galbraith , Sebastian Andrzej Siewior Subject: [PATCH v2 3/3] zram: Shrink zram_table_entry::flags. Date: Thu, 20 Jun 2024 17:28:52 +0200 Message-ID: <20240620153556.777272-4-bigeasy@linutronix.de> In-Reply-To: <20240620153556.777272-1-bigeasy@linutronix.de> References: <20240620153556.777272-1-bigeasy@linutronix.de> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 The zram_table_entry::flags member is of type long and uses 8 bytes on a 64bit architecture. With a PAGE_SIZE of 256KiB we have PAGE_SHIFT of 18 which in turn leads to __NR_ZRAM_PAGEFLAGS = 27. This still fits in an ordinary integer. By reducing it the size of `flags' to four bytes, the size of the struct goes back to 16 bytes. The padding between the lock and ac_time (if enabled) is also gone. Make zram_table_entry::flags an unsigned int and update the build test to reflect the change. Signed-off-by: Sebastian Andrzej Siewior --- drivers/block/zram/zram_drv.c | 3 ++- drivers/block/zram/zram_drv.h | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 659966e00c300..a35d4bd2e60ef 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -2412,9 +2412,10 @@ static void destroy_devices(void) static int __init zram_init(void) { + struct zram_table_entry zram_te; int ret; - BUILD_BUG_ON(__NR_ZRAM_PAGEFLAGS > BITS_PER_LONG); + BUILD_BUG_ON(__NR_ZRAM_PAGEFLAGS > sizeof(zram_te.flags) * 8); ret = cpuhp_setup_state_multi(CPUHP_ZCOMP_PREPARE, "block/zram:prepare", zcomp_cpu_up_prepare, zcomp_cpu_dead); diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h index 262fa960a0783..531cefc666682 100644 --- a/drivers/block/zram/zram_drv.h +++ b/drivers/block/zram/zram_drv.h @@ -66,7 +66,7 @@ struct zram_table_entry { unsigned long handle; unsigned long element; }; - unsigned long flags; + unsigned int flags; spinlock_t lock; #ifdef CONFIG_ZRAM_TRACK_ENTRY_ACTIME ktime_t ac_time;