From patchwork Fri Jul 5 12:49:16 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: 13725067 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 12879149C4C; 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=1720183865; cv=none; b=roWCDqe2ktIwai6Xs0YHlAA661jvQCdXVGzg0cyWdp2XspdKbZBeFSWUvYUeUtSyNSM6HJ2x4E4mwA7ZTcV3QnirSuibW2Grt/dCPjECnRdZUdrWZh6FQQO0Zz7iSj/yiTjWuRZNcwXV8Z24C7U8+Ks+vQgou/iZcYhfaHxr8BI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720183865; c=relaxed/simple; bh=Tg+HfrYUbcTf4m66IXzTHsNS/XoVI55Nli/4Xak15iE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=D6Am0C0hStCkuHgXfDrVwADrkpBgqOqIeRi7tj7ufxN0W4PMNPEE1Gl3zYuFZHtLfsKGvO5LF/UbbZ9g2NnX68buqtQrLetG/FA8G/ewUACoA70m0dFN0FxaMnkWEwN7gpy3pFkVaaciM7OEGpXElzpRkDR1xxJjBBNMVr+O2Ic= 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=fDxWzmg3; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=PQxtIIzm; 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="fDxWzmg3"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="PQxtIIzm" 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=rsG//7rYWfTYC6on5Th6BnejVdtNYOCn5Z8HIMJ/YeQ=; b=fDxWzmg3YY81rEeuzXL27xU06qWVtKUxjjFZrGY1Dbf0zv0PI7gQ3eRupdJdEuICO4NXVZ PK/nTwT9PD0bcSbaRMmx19CNqP6LqfqsJjMKh4B6zXmEgHRtAghA+4XkDvrlpSanZN5zDY oAIUvXXYG8T6fafDYuIu2tlnEiUeGSYgXfioylQJARJdZlNk4hGERYhSP8RRPChXOIg1R6 VrOPGW+vHA3tbqFRcPSLFBPOD/hQNOjxD+TC/Ltg5r4r4/8RSSYIWoAO518HKxuWWzhsRZ cTuWtgXsbs/rSNm40iogbtsvoBb+lAY5qAhyXxzzBB+PQfkqmqUWY9jGliKitg== 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=rsG//7rYWfTYC6on5Th6BnejVdtNYOCn5Z8HIMJ/YeQ=; b=PQxtIIzmgXyoxV6rzhzILNTiKI1nRtHPWw2n1dzhwBCg+lF4R1TY1YNZwCNz1uEHbBxqmc FGfu9sfhQMomfZBQ== 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 3/3] zram: Shrink zram_table_entry::flags. Date: Fri, 5 Jul 2024 14:49:16 +0200 Message-ID: <20240705125058.1564001-4-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 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. Reviewed-by: Sergey Senozhatsky 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 e683a9fc68b6c..dde45a084733f 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -2410,9 +2410,10 @@ 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;