From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qk1-f171.google.com (mail-qk1-f171.google.com [209.85.222.171]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7C7E14E13FF for ; Fri, 4 Sep 2026 16:53:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.222.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788540826; cv=none; b=eP0K+IxLWwACXA/CglwQIhuFbTZmbkvWD7/p0gH+i+bQMw2TFItzWzswU3k8rYu2WotipY7LZNFHnc3/p587ga4xtKGpx03xFawBxr8LLyY0HK5Izc8l70wX35bp4UEuRCJjziRc8ICvpCPO+q/Eu1i0VEWaTcBZuSppTlLvDO8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788540826; c=relaxed/simple; bh=uwyW9w/1ZciAbVAqAmY0cI45bHrXrtOA8e0h6tY65/8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=afPcT6iL+yTyysbVb/GMTIdyR6CNru6efu1eN5q/8AESpdJVHO5BVeYkBUi00mmX5kUFw4E8gRsD1HL1tJavePOT/TznZFpMOW9ZUJSkXQiSVJnEXu68QmDV8fsupm0pPuTF8MVhQwomn/8p+UbaA6UrS2ITZDdz6l0BKwzc/w8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=hammerspace.com; spf=pass smtp.mailfrom=hammerspace.com; dkim=pass (2048-bit key) header.d=hammerspace.com header.i=@hammerspace.com header.b=R/xIdfCv; arc=none smtp.client-ip=209.85.222.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=hammerspace.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=hammerspace.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=hammerspace.com header.i=@hammerspace.com header.b="R/xIdfCv" Received: by mail-qk1-f171.google.com with SMTP id af79cd13be357-938cd95b06eso134075185a.1 for ; Fri, 04 Sep 2026 09:53:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=hammerspace.com; s=google; t=1788540823; x=1789145623; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=HxD/tKN5i/ZhMh3kPjgA/bAelNOrwdAP+IUTKzFlpc8=; b=R/xIdfCv/TffHaDOMhzZDrRk04am+lTcr01FydGWyL4vclvUzsaD6DeZY98waqdsbO 66i7baz7ArhQODx69W0hdiih46Bte6AoDg5SYNlYvPNr6Zj/0lgzo8fqUnd3+6NT1quJ tvinRPhR/WjkDXGBa23glHtLpVbMDitCv63qORdJozMIVzPAfFZk0YPr60cqRYG15ePK CzOJCfAqD053D+yMAHdTfHR4bew9FNSpPPx1gvobeWpstyYGKxveJTorq9q3n0Fbau/g yojrJSpxaiNvvhyHkAWT61M0qDOKCM1zECjKX6HsA8MFSWC3e8h3uE1t1jGUBjA9H5Ui nMZA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788540823; x=1789145623; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=HxD/tKN5i/ZhMh3kPjgA/bAelNOrwdAP+IUTKzFlpc8=; b=IKMHTegNByTHL8heewKRJKekF7dQR7LTGBsDD8pPqgle58G0zKkYJ0PPWkd/xM/rPg 4FHg4UpRo7cpSAdxDu96jx8oscfW4Chu0SVJqSzRLrWcDusOQP6WPW9jvb07SLbOX4CS EmnUC/Rob0dFizhgvZR13NRDU19Uakv+IkZuz86asO14rWIyw2M1tl6YIthvcfTcwghQ rFJAsrlgEEODjdz7/pZbAlT0LUfLXEiqHRK4lgOy+z+gi7iEmWjloY/ea9ZTBcfAydsH sA0cN26Yw949g9dbY+LZN+bf8FXbb6MYiYryaZLqCY3nAidOrSSU7ZHJqoxiamgM7xrG 4eCA== X-Gm-Message-State: AFuF++nA7RjxySDlnuKq7AqQLhXdDv87Kq7/GbZhP8LATeiCE/hewMtM a+Tobs2cwzDl725cod/sFgovS2JQL+qjRcZKgJVNs3F+8yl2MEY/c8CaSAEBKH4MI5U= X-Gm-Gg: AYBFou2riIfeA1cVDbrZgLkMvZ7M1s91f0AZopJ9Se5uVDhjsEmXE/XLWfIf70STSPn +cqYCN75z5G1ls//CYYA19RHL9cY4VIy/C70e/44Zns2q80MPbqbcj71mnUO27goo3n5BIWGA91 3tTcQ6sdQ3UdRKneQXySfA2JpfaCH2CAuxcXI4lzn84TJbJmpKtxmR2tXU9Gl8XPIqk+q+lx9/Y LExfCcHEeuPiIaHnB32nrky0VUxCK5o8Og+6is3yTYXGRlLZk5qouuHxkDcW7swElWabx+8jYNN yNp64GJEZEn5ksJRfEj4BlwPWVVoEYf1YAC2U3ON/h93G5jhqnIRfkAzRTA9BXdpXX6ZsWKKLrw 17LEgV7obVYTcw6XmSW1zxYYPhq+8iXptGFf0BvOBavw3Ko0DWrZwtcC5dV9Jwq4w4dmCxs34sD 0iWDGJxQuqDGikMq7Lk9+PZ7CHFWTAEpeqM0/OifGh5pXN8/mmMYStHAyy+3GGtLEdGBeaxbubr xIPx+Ds0ZgUSAnW+rUHj6Yai+fbS3NxBOI= X-Received: by 2002:a05:620a:2257:20b0:939:8f2b:37dd with SMTP id af79cd13be357-9398f2b388fmr44767085a.24.1788540823286; Fri, 04 Sep 2026 09:53:43 -0700 (PDT) Received: from bcodding.csb.hammerspace.com ([66.97.168.37]) by smtp.gmail.com with ESMTPSA id af79cd13be357-9397fbf7c78sm248145485a.47.2026.09.04.09.53.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 04 Sep 2026 09:53:43 -0700 (PDT) From: Benjamin Coddington X-Google-Original-From: Benjamin Coddington To: Trond Myklebust , Anna Schumaker Cc: linux-nfs@vger.kernel.org, Jonathan Curley , Mike Snitzer , Jeff Layton , Junrui Luo Subject: [PATCH v3 21/24] NFSv4/pnfs: Grow the deviceid cache hash table Date: Fri, 4 Sep 2026 12:53:20 -0400 Message-ID: X-Mailer: git-send-email 2.53.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The global deviceid cache has 32 buckets shared by every server and layout type. Striping deployments initially anticipate device counts scaling to 1024 or more devices, which leaves those chains 32 entries deep for every resolution to walk. Grow to 256 buckets, four deep at that scale, for 2KB of BSS on 64-bit. Assisted-by: Claude:claude-fable-5 Signed-off-by: Benjamin Coddington --- fs/nfs/pnfs_dev.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/fs/nfs/pnfs_dev.c b/fs/nfs/pnfs_dev.c index a3b28409539a..e8143977965c 100644 --- a/fs/nfs/pnfs_dev.c +++ b/fs/nfs/pnfs_dev.c @@ -40,8 +40,11 @@ /* * Device ID RCU cache. A device ID is unique per server and layout type. + * + * 256 buckets keeps the chains short at the 1024-or-more devices a + * striping deployment expects, for 2KB of BSS on 64-bit. */ -#define NFS4_DEVICE_ID_HASH_BITS 5 +#define NFS4_DEVICE_ID_HASH_BITS 8 #define NFS4_DEVICE_ID_HASH_SIZE (1 << NFS4_DEVICE_ID_HASH_BITS) #define NFS4_DEVICE_ID_HASH_MASK (NFS4_DEVICE_ID_HASH_SIZE - 1) -- 2.53.0