From patchwork Fri Nov 24 07:34:38 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Liang Chen X-Patchwork-Id: 13467091 X-Patchwork-Delegate: kuba@kernel.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="LA8rtDH5" Received: from mail-pj1-x102a.google.com (mail-pj1-x102a.google.com [IPv6:2607:f8b0:4864:20::102a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B94F7D4E for ; Thu, 23 Nov 2023 23:35:26 -0800 (PST) Received: by mail-pj1-x102a.google.com with SMTP id 98e67ed59e1d1-280351c32afso1414422a91.1 for ; Thu, 23 Nov 2023 23:35:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1700811326; x=1701416126; 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; bh=1wf42jdW+6K8AfiyHVKHn1gShiAo7E/o6JslnDYKix8=; b=LA8rtDH57cmU9cXm8gNs6G6kFsgPvmHHZcRB77XRmZcJv/9F/eUnHs+aHj/6au/jX9 n24+Z3jvIua5VbuhiXhTSCGz9MNpDm+M5RC3/HhNl5uCLck5TyloqFG/81QjR17Ey8lv yX4Uxui8Hwm4XRUol/uGbuaeBW/Wh9tY9+sEoX8X9c11HzDz7Ss1kcveOixWABWzRw9o WsV00wkTHv193aMp0KNJQ7wRCmtPZHGgppl0V+vA4ZlVwjXK4SP1W7QXQ9CyDYMJbGA8 ZYnDPoj0vSvPNiRdviZkNBT4c3C4yDaDI9FNCUe7R+kqWpjfX2JJuKaw1nBAZXknavQJ /wgw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1700811326; x=1701416126; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=1wf42jdW+6K8AfiyHVKHn1gShiAo7E/o6JslnDYKix8=; b=Q+HkqUgcp+/ljc7QlLyBGOWaGtq64cZ8sorOrZLPNJTrPVXysEfr3fZXSDnP94AnLD FdRxuSdU8btz09bwXHIXApr8LiX57kdg2gb2tDm7T1JiI77xApIl3vOKJhQ/sldixSWr fKj+BHZ3cihNqQfOHmxea2gLIFEv4WyMLU//2QnYU8SPvmznInMPj315eGghhNKrce/h /HX5uXt6aNM6phsCIYEhDlgdX+n0Ol3FkZPLGpWRno1ASaeheaShdfzBQeuF9Pxs9p1y Vox3fCVW8w2qUN3udReiFJbyYwwuWrUAy8vnOWRToSEjeAxbcYIb+mcViBJKD86n1Pkb ePlw== X-Gm-Message-State: AOJu0YxiIoemRm0gwz5SkW+2F0GxBoDTZaD09IZMhpqoQ2GSJ/4zTdMh 8h/NHqSyITJDQ0w/Sm5ROdg= X-Google-Smtp-Source: AGHT+IFqMZHO8+ERbxfOGumOXWVCKIXwMpvkdMGN1wW1029LzQCwFYJqLpbWoY21lciZ/9bahTIfaw== X-Received: by 2002:a17:90a:bb95:b0:285:68f3:80c0 with SMTP id v21-20020a17090abb9500b0028568f380c0mr1910144pjr.12.1700811325979; Thu, 23 Nov 2023 23:35:25 -0800 (PST) Received: from localhost.localdomain ([89.187.161.180]) by smtp.gmail.com with ESMTPSA id t15-20020a170902e84f00b001b9d7c8f44dsm2499329plg.182.2023.11.23.23.35.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 23 Nov 2023 23:35:24 -0800 (PST) From: Liang Chen To: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, hawk@kernel.org, ilias.apalodimas@linaro.org, linyunsheng@huawei.com Cc: netdev@vger.kernel.org, linux-mm@kvack.org, liangchen.linux@gmail.com Subject: [PATCH net-next v3 2/3] page_pool: halve BIAS_MAX for fragment multiple user references Date: Fri, 24 Nov 2023 15:34:38 +0800 Message-Id: <20231124073439.52626-3-liangchen.linux@gmail.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20231124073439.52626-1-liangchen.linux@gmail.com> References: <20231124073439.52626-1-liangchen.linux@gmail.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org Referring to patch [1], in order to support multiple users referencing the same fragment and prevent overflow from pp_ref_count growing, the initial value of pp_ref_count is halved, leaving room for pp_ref_count to increment before the page is drained. [1] https://lore.kernel.org/all/20211009093724.10539-3-linyunsheng@huawei.com/ Signed-off-by: Liang Chen Reviewed-by: Yunsheng Lin --- net/core/page_pool.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/core/page_pool.c b/net/core/page_pool.c index 0c6c2b11aabe..24b83dfe6968 100644 --- a/net/core/page_pool.c +++ b/net/core/page_pool.c @@ -26,7 +26,7 @@ #define DEFER_TIME (msecs_to_jiffies(1000)) #define DEFER_WARN_INTERVAL (60 * HZ) -#define BIAS_MAX LONG_MAX +#define BIAS_MAX (LONG_MAX >> 1) #ifdef CONFIG_PAGE_POOL_STATS /* alloc_stat_inc is intended to be used in softirq context */