From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 E02654F4CF8 for ; Fri, 2 Oct 2026 16:25:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790958310; cv=none; b=IDUNV4C/maaqKs/v4edyoOmU0VfO6gQMeB7pB3XST/os/HcRJGd9JTAGPgSg7TrqSUzoCXTTmxHZZZA6c4kY9UDilpG7ko0DFsW7KCKKECteU0CdEeqv6oP6ugQ7SfU7SM+7KYpr/fGk/INx9I+9tvML2zsSSnycsgFIP8bLo+E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790958310; c=relaxed/simple; bh=5avW5tSTUbimjlF+wRQM9RHoLcDbWco8LNjbcA2YiMs=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=kLP/7wyyI2WXPCO/WONjK9xm1wKmUUiwyzGEXANkpTCgYuJykzDyXOq/svFu5H0LX0QzDPpx9u7acb6zv3SYr9hl9QG6wG+9B4gVdWWFBtOHlbsuxdlFIBRn30DDpOZvbaEgrGbs4kwM/+J28KuCSqIc8JU6SPOsOoE64QZba58= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=iNfQgqtG; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="iNfQgqtG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0B9091F000FF; Fri, 2 Oct 2026 16:25:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790958308; bh=ZpHAkAUEr8Xl3PYCBuALwZnX7kTAqTO4j89M73nBzd0=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=iNfQgqtGgT3dWHPL27LYCxX8M7xpbJaGHO5iR6zSzjzhWDl+o//WG9WvDMN2IXiT2 gTJ0uxJsuZMP8Fv5F+WdFKNUyUKW9aKRCBWfK9dbdggn8nMKChj/ptgHzXbAATyRYp wcC6XMHSL1V3TK9xd2MzuOgGrvRVFl3Q8I+3cUNYkQKge7OOkR24oGUeB5Q/AQQPQI ojHwB1gkeGWXYys59a79PSGJMapLfDADFYDITg3tPYGuL3Hl7szfhZz6MRSjFdDuXt BfdvtpPo8xSQCmg5oi89wWlSC+TzM2bc6EdaF1jDjigpyQupHXoD8sV5Lxv81CbEcd C4XuPihm7sxVg== From: Linus Walleij Date: Fri, 02 Oct 2026 18:24:47 +0200 Subject: [PATCH net-next v3 08/12] net: ethernet: cortina: Rotate free queue page allocation Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20261002-gemini-ethernet-fixes-3-v3-8-3e1f25890ae8@kernel.org> References: <20261002-gemini-ethernet-fixes-3-v3-0-3e1f25890ae8@kernel.org> In-Reply-To: <20261002-gemini-ethernet-fixes-3-v3-0-3e1f25890ae8@kernel.org> To: Hans Ulli Kroll , Andrew Lunn , "David S. Miller" , Jakub Kicinski , Paolo Abeni , =?utf-8?q?Micha=C5=82_Miros=C5=82aw?= , Myeonghun Pak , Eric Dumazet Cc: netdev@vger.kernel.org, Linus Walleij X-Mailer: b4 0.16.0 The free queue metadata bitmap currently searches for a free slot from zero for every page allocation. Under sustained traffic this repeatedly scans occupied low-numbered slots. Remember the position after the most recently allocated slot and wrap the bitmap search at its end. This keeps allocation cost distributed across the metadata table. Fixes: 4d5ae32f5e1e ("net: ethernet: Add a driver for Gemini gigabit ethernet") Assisted-by: LLM Signed-off-by: Linus Walleij --- drivers/net/ethernet/cortina/gemini.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/cortina/gemini.c b/drivers/net/ethernet/cortina/gemini.c index 2345d582cb59..87c537ae83e7 100644 --- a/drivers/net/ethernet/cortina/gemini.c +++ b/drivers/net/ethernet/cortina/gemini.c @@ -172,6 +172,7 @@ struct gemini_ethernet { struct xarray freeq_mappings; unsigned int num_freeq_pages; unsigned long *freeq_page_bitmap; + unsigned int freeq_page_cursor; spinlock_t freeq_lock; /* Locks queue from reentrance */ }; @@ -743,12 +744,20 @@ static int geth_freeq_alloc_slot(struct gemini_ethernet *geth) lockdep_assert_held(&geth->freeq_lock); - slot = find_first_zero_bit(geth->freeq_page_bitmap, - geth->num_freeq_pages); - if (slot == geth->num_freeq_pages) - return -ENOSPC; + slot = find_next_zero_bit(geth->freeq_page_bitmap, + geth->num_freeq_pages, + geth->freeq_page_cursor); + if (slot == geth->num_freeq_pages) { + slot = find_first_zero_bit(geth->freeq_page_bitmap, + geth->freeq_page_cursor); + if (slot == geth->freeq_page_cursor) + return -ENOSPC; + } __set_bit(slot, geth->freeq_page_bitmap); + geth->freeq_page_cursor = slot + 1; + if (geth->freeq_page_cursor == geth->num_freeq_pages) + geth->freeq_page_cursor = 0; return slot; } @@ -1110,6 +1119,7 @@ static int geth_setup_freeq(struct gemini_ethernet *geth) if (!geth->freeq_page_bitmap) goto err_freeq_pages; geth->num_freeq_pages = page_slots; + geth->freeq_page_cursor = 0; expected = len - (1 << fpp_order); filled = geth_fill_freeq(geth); -- 2.55.0