From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=62.210.214.84 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793253626; b=tzGvCH9CIhQt+umOw652Ms8Ja11nuuWkY0zo84FdyIUIuJ6J7yp5uleQZYQN6pVxKEMa b0mISd8+oijURfah/W2I9OrHo5Fxbzyab9u/u/QbCG65T7HZUgeySFCzODQ2kJ8XXispO kSaGdFiXx5KNHobafVlrfsKyij6OnnDIK2v+PfrkSV6PB1X80R1AKr+SE3RTIz95IqEm9 UiCvKGexbbvHKHjcFVJDvmcYW2MvYLOH2onue6w+md5PRp7NfcSPszwynu8M0PdPyU4W8 DVaLktfR57wZVaKtlw9KbIJKxXyNR6yb/tkMKx8N6JM9b9mZhk61YYyv+irvjrLzLuQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793253626; h=DMARC-Filter:Received:DKIM-Signature:Received:From:To:Cc:Subject: Date:Message-ID:X-Mailer:MIME-Version:Content-Transfer-Encoding; bh=vOGC1ex5Knc4gUvwls9OSLa63qIjRIYMiD8fFkiWwrE=; b=JoHcxVnLnNs+P0r4xoSl+FDTLH/WRTn1VGtQBcqfjcFsQudsq1PbJz2GHSh3AqrgcF0O +IUwIUikrP9W5jQCxEkGmEuD9G+cqL6MNlqGY6SdctShfxDU5F4V5ZfS5BoENToi4Bx4i YEQhDE5+N5IH+iKro7WAW0wL5GuY8s1ts9bN5iWZfM78zhOG//AT7QLz9uESelnt/smAN FSG+nHsLurES7QwMf4URhQjEfcGSZkB4NfezZLqT3+EMFxmCwqq3nnuwylFbBVX57xQYE qs3dxNVykf+n55BsLCrCap8dQEMFItGmMtTwPYhRrKp72h8XJJ0ErgBSerTm75I/yGw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=codewreck.org; spf=pass smtp.mailfrom=codewreck.org; dkim=pass header.d=codewreck.org header.i=@codewreck.org header.a=rsa-sha256 header.s=2 header.b=QJmOLFkT; arc=none smtp.remote-ip=62.210.214.84 Received: from submarine.notk.org (submarine.notk.org [62.210.214.84]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E582B606A32E for ; Thu, 29 Oct 2026 06:00:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org E582B606A32E Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=codewreck.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=codewreck.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=codewreck.org header.i=@codewreck.org header.a=rsa-sha256 header.s=2 header.b=QJmOLFkT Received: from gaia.codewreck.org (localhost [127.0.0.1]) by submarine.notk.org (Postfix) with ESMTPS id 69EED14C2D6; Thu, 29 Oct 2026 07:00:20 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=codewreck.org; s=2; t=1793253622; 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; bh=vOGC1ex5Knc4gUvwls9OSLa63qIjRIYMiD8fFkiWwrE=; b=QJmOLFkTugrCihej57+Q0f0P+SXn029yLmYWE0Kb7/AJOyQd6ujIpzmsG9B27FMaphwiI3 Vx1qX/AJjRgo65RrelaK6gtkJEGY98z/o72aEYn0wQZuWVqVR1GWzEZojbjDaQSP1ba9UV Rk5WD/KqdrM0MRORpaevjUgcqmqVKgMGNzIbwXttqaHHYuLpoQ7QjmtVPkPcdeIrM35Hqz PmFdpbgsTvnjMa/x/GTXtgTygD/HsA0/BSVwaW19RcZvG3uAP6GJPH30M7zGpjyH/8a9t8 1tGXjvX1/D1QHL+mHEc85Imj/t7ekleGMgBB28hqKQIgyY6skQCHlSXGT85M+A== Received: from gaia.codewreck.org (localhost.lan [127.0.0.1]) by gaia.codewreck.org (OpenSMTPD) with ESMTP id 506b6a35; Thu, 29 Oct 2026 06:00:18 +0000 (UTC) From: Dominique Martinet To: Eric Van Hensbergen , Latchesar Ionkov , Dominique Martinet , Christian Schoenebeck Cc: v9fs@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH] 9p: optimize p9_fcall struct Date: Thu, 29 Oct 2026 06:00:12 +0000 Message-ID: <20261029060014.3-1-asmadeus@codewreck.org> X-Mailer: git-send-email 2.54.0 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit p9_fcall has a 1 byte hole followed by more data and then a single byte element: struct p9_fcall { u32 size; /* 0 4 */ u8 id; /* 4 1 */ /* XXX 1 byte hole, try to pack */ u16 tag; /* 6 2 */ size_t offset; /* 8 8 */ size_t capacity; /* 16 8 */ struct kmem_cache * cache; /* 24 8 */ u8 * sdata; /* 32 8 */ bool zc; /* 40 1 */ /* size: 48, cachelines: 1, members: 8 */ /* sum members: 40, holes: 1, sum holes: 1 */ /* padding: 7 */ /* last cacheline: 48 bytes */ }; move `zc` up to optimize it: struct p9_fcall { u32 size; /* 0 4 */ u8 id; /* 4 1 */ bool zc; /* 5 1 */ u16 tag; /* 6 2 */ size_t offset; /* 8 8 */ size_t capacity; /* 16 8 */ struct kmem_cache * cache; /* 24 8 */ u8 * sdata; /* 32 8 */ /* size: 40, cachelines: 1, members: 8 */ /* last cacheline: 40 bytes */ }; This in turn also makes p9_req_t 16 bytes smaller (152 -> 136) as it contains two of these. Signed-off-by: Dominique Martinet --- include/net/9p/9p.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/net/9p/9p.h b/include/net/9p/9p.h index 22ab7486795d..067e8a3b38d0 100644 --- a/include/net/9p/9p.h +++ b/include/net/9p/9p.h @@ -581,6 +581,7 @@ struct p9_rstatfs { struct p9_fcall { u32 size; u8 id; + bool zc; u16 tag; size_t offset; @@ -588,7 +589,6 @@ struct p9_fcall { struct kmem_cache *cache; u8 *sdata; - bool zc; }; int p9_errstr2errno(char *errstr, int len); -- 2.56.0