From patchwork Wed Nov 29 11:23:02 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Liang Chen X-Patchwork-Id: 13472674 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="MJE3YEDo" Received: from mail-pl1-x62a.google.com (mail-pl1-x62a.google.com [IPv6:2607:f8b0:4864:20::62a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 33B4784 for ; Wed, 29 Nov 2023 03:24:40 -0800 (PST) Received: by mail-pl1-x62a.google.com with SMTP id d9443c01a7336-1cfafe3d46bso40421375ad.0 for ; Wed, 29 Nov 2023 03:24:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1701257079; x=1701861879; 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=J730iItaW8fpD9bcYiCc3WSDtwgBtsyA2Jb0R83edv4=; b=MJE3YEDomm+q64RgS20iNU4RPU2TQtqr0PuVkvC2o63KjVPGHw0Xgzq5Sg1N6vGY4n cWLkRsPpVqx9pasoHboCVrX/bx/gZEmWsm3O0jasn/nVrRzJZJ0ocGLGbHssos2zvQb3 llFJuF/PDYeb7BLz8rPMDd0u7QEItjsN0JSwJdaEu1JSmBRR5mZwKrs53q2Nu1Ha2MGG JvanYvdRjsHb+vRWVT6lhxrvYfqx1WZt9Whl9gWe8EjQt6gccnR53wGRVZctW55OrbdG c3x12x6210DVIgw40n43NR8q1BB6h3S2Lr7DbFGo2DBpYW9wicRLw7b/lltwnBR/dJV4 ++cQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701257079; x=1701861879; 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=J730iItaW8fpD9bcYiCc3WSDtwgBtsyA2Jb0R83edv4=; b=HxvFTFgysGdGJVy+Eq2Sw7/mazBc4CUqP1foCo1+IwF7CSSLQpjuKOpdgTqLOSPZxM 46QnDdLAmEz8GibpA/vbp1rubeK6m4GEiSM6pji+pLzsLMJXTy2bC/hMiK5OXUDrfj7N 4x6YWtF+LGTOlgEexH6Q8aWsnQsE9PmaK2uHQdMqIR5wdtO5i0j5Z7GBJ3QnPJp6Z5UO kLSBXXXRt92ibFaY8i6wSQMf4HumgYaIl4W4Eyttnbwn2D2kZDEwJTXMvQg5HzbBdiI1 t/rCzowkduxOrBIWHuCgc/My5816m8x3H5d+jZYdivR1EKWFbNg3j8PBWzqBjVrIRZWC Zp6g== X-Gm-Message-State: AOJu0Yxcl42rtaFJNavkY382N70uPde57wQZmIoyY/0U1Bkm6mc7B73Q cvdTfxy3+8jjx36ndXvo1X8= X-Google-Smtp-Source: AGHT+IGend3+KRvVWg3wiKEnDCJRXZQxRXIpsrnkvu2W3MzYQdcBsY89G98gXH/coDoEQKUh9fTDxQ== X-Received: by 2002:a17:903:32c8:b0:1cf:73ff:b196 with SMTP id i8-20020a17090332c800b001cf73ffb196mr24920528plr.8.1701257079629; Wed, 29 Nov 2023 03:24:39 -0800 (PST) Received: from localhost.localdomain ([89.187.161.180]) by smtp.gmail.com with ESMTPSA id c6-20020a170902c1c600b001cfd0ed1604sm5460710plc.87.2023.11.29.03.24.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 29 Nov 2023 03:24:38 -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 v5 2/4] page_pool: halve BIAS_MAX for multiple user references of a fragment Date: Wed, 29 Nov 2023 19:23:02 +0800 Message-Id: <20231129112304.67836-3-liangchen.linux@gmail.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20231129112304.67836-1-liangchen.linux@gmail.com> References: <20231129112304.67836-1-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 106220b1f89c..436f7ffea7b4 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 */