From nobody Tue Nov 26 09:39:08 2024 Received: from mail-pl1-f172.google.com (mail-pl1-f172.google.com [209.85.214.172]) (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 07E7481AB6 for ; Mon, 21 Oct 2024 01:54:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729475644; cv=none; b=VUPRgXpCu+jlRo74PvF5K6gcbXuOxC2Fw6aGn1IhYNtEbthM2aiAzZTLjaJ8cPSrn67BgHPupWuvDh3YvD/CMp9STRveJk0OMNpDWj2uMWi94S1R3amCEdHAMPXVkaTuT137zgLJdmJE/365H07fotK81Rkd+zcOSujQACg6bCY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729475644; c=relaxed/simple; bh=+v/H79GmiAG3naN0zeRg2nElJUiBqVhmyL2Hh1hlU1E=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=nMDL3gAIz4V/u+U0QDgyIQx9Rl5It8KYBnzYjFtTSA2xnJ8LW3YKnNfrfzfrN87yPsu/SyD1NvrjqQmJe1vGQ4teEdy4XRV07z002DDRstgvRBWQu0JEq6/j10UAnYm1CgdoFR4IlciI1kwrr31FkZBjDj3BJOCCq6GmmqMaxIo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=fastly.com; spf=pass smtp.mailfrom=fastly.com; dkim=pass (1024-bit key) header.d=fastly.com header.i=@fastly.com header.b=jPaPMNaz; arc=none smtp.client-ip=209.85.214.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=fastly.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=fastly.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=fastly.com header.i=@fastly.com header.b="jPaPMNaz" Received: by mail-pl1-f172.google.com with SMTP id d9443c01a7336-20c9978a221so45388445ad.1 for ; Sun, 20 Oct 2024 18:54:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fastly.com; s=google; t=1729475642; x=1730080442; 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=JmUjBpdJ0f8V/MHrwl+AGewKk5aAt+i1MtpvNR8b1Y8=; b=jPaPMNazIG9wKFrhCiVuME+1DCpbm3buJdEvqMBu/yXUuXMFWHrj7IiEkhnaMV9KZJ m/m5dncBvKrF9U0CB2ZPEaBkp0Xf5w3ftOpoeYIiyM0UI2HBOIQtaAGg+2iSzFbdH23f Sug6HtzSIp23FZ2OWhTySPXE8KVAlx60d5GTo= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1729475642; x=1730080442; 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=JmUjBpdJ0f8V/MHrwl+AGewKk5aAt+i1MtpvNR8b1Y8=; b=nFzOczKsrQXhEuoyclqmsJitxaeM7YxJcCyxz4nEkkHHbV5p2dxqr+qAJt9zqKUoJ8 2cgt5h7SIGyyCFGXSyYO2fuGxv1i4S8V8i2D8dPnFucLIgw0jx+TCIChrkKZst6xGSKl a8Eue9Ae9tsb53FIuUMCGFtz1frNiklDTcFGYxTPOByEM5Ziu2Eho5ZioQn356ok8Aso aprYRsciKqCok45yBHON/cGTNyakYhNG5DLU3HjCxfPHvfLSPGusZRMl0pmdV8JwtUYk Qe7qiYM/G+mxBZlzW1nYW1dmaE0MaK+UVoxpszLeDMevqKjQ/XUIM8YGx4UFc605WeFs ZaDQ== X-Forwarded-Encrypted: i=1; AJvYcCVv3RAqojqkcTuqsNp/K4LLtkUyAqwjPNcv6Mz15PSWdlBBU1xdxUUlmsx5qbLXQHjtoQvH2DoctZiOERk=@vger.kernel.org X-Gm-Message-State: AOJu0Yz6iWgh28Q2vZXNX7Q245dtE04YXkojEjuNnqbAgcwhXu4/jw+9 LvBcWX6emeNto5yREMldmNWY++fBX9f7Oos6YPsz32NYK27NPFFGC2GBgDCldQY= X-Google-Smtp-Source: AGHT+IGVda21+4TkdnbM/4Q+uHbJcBEZbiTKQt97djp2s9YV3IPbRBsjbBBv8Rl+668P90LjyRMasw== X-Received: by 2002:a17:902:f906:b0:20b:8776:4906 with SMTP id d9443c01a7336-20e5a8ee770mr105564285ad.37.1729475642435; Sun, 20 Oct 2024 18:54:02 -0700 (PDT) Received: from localhost.localdomain ([2620:11a:c019:0:65e:3115:2f58:c5fd]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-20e7eee650bsm15859985ad.34.2024.10.20.18.54.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 20 Oct 2024 18:54:01 -0700 (PDT) From: Joe Damato To: netdev@vger.kernel.org Cc: namangulati@google.com, edumazet@google.com, amritha.nambiar@intel.com, sridhar.samudrala@intel.com, sdf@fomichev.me, peter@typeblog.net, m2shafiei@uwaterloo.ca, bjorn@rivosinc.com, hch@infradead.org, willy@infradead.org, willemdebruijn.kernel@gmail.com, skhawaja@google.com, kuba@kernel.org, Martin Karsten , Joe Damato , Alexander Viro , Christian Brauner , Jan Kara , linux-fsdevel@vger.kernel.org (open list:FILESYSTEMS (VFS and infrastructure)), linux-kernel@vger.kernel.org (open list) Subject: [PATCH net-next v2 5/6] eventpoll: Control irq suspension for prefer_busy_poll Date: Mon, 21 Oct 2024 01:53:00 +0000 Message-Id: <20241021015311.95468-6-jdamato@fastly.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20241021015311.95468-1-jdamato@fastly.com> References: <20241021015311.95468-1-jdamato@fastly.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Martin Karsten When events are reported to userland and prefer_busy_poll is set, irqs are temporarily suspended using napi_suspend_irqs. If no events are found and ep_poll would go to sleep, irq suspension is cancelled using napi_resume_irqs. Signed-off-by: Martin Karsten Co-developed-by: Joe Damato Signed-off-by: Joe Damato Tested-by: Joe Damato Tested-by: Martin Karsten --- rfc -> v1: - move irq resume code from ep_free to a helper which either resumes IRQs or does nothing if !defined(CONFIG_NET_RX_BUSY_POLL). fs/eventpoll.c | 31 ++++++++++++++++++++++++++++++- 1 file changed, 30 insertions(+), 1 deletion(-) diff --git a/fs/eventpoll.c b/fs/eventpoll.c index f9e0d9307dad..36a657594352 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -457,6 +457,8 @@ static bool ep_busy_loop(struct eventpoll *ep, int nonb= lock) * it back in when we have moved a socket with a valid NAPI * ID onto the ready list. */ + if (prefer_busy_poll) + napi_resume_irqs(napi_id); ep->napi_id =3D 0; return false; } @@ -540,6 +542,22 @@ static long ep_eventpoll_bp_ioctl(struct file *file, u= nsigned int cmd, } } =20 +static void ep_suspend_napi_irqs(struct eventpoll *ep) +{ + unsigned int napi_id =3D READ_ONCE(ep->napi_id); + + if (napi_id >=3D MIN_NAPI_ID && READ_ONCE(ep->prefer_busy_poll)) + napi_suspend_irqs(napi_id); +} + +static void ep_resume_napi_irqs(struct eventpoll *ep) +{ + unsigned int napi_id =3D READ_ONCE(ep->napi_id); + + if (napi_id >=3D MIN_NAPI_ID && READ_ONCE(ep->prefer_busy_poll)) + napi_resume_irqs(napi_id); +} + #else =20 static inline bool ep_busy_loop(struct eventpoll *ep, int nonblock) @@ -557,6 +575,14 @@ static long ep_eventpoll_bp_ioctl(struct file *file, u= nsigned int cmd, return -EOPNOTSUPP; } =20 +static void ep_suspend_napi_irqs(struct eventpoll *ep) +{ +} + +static void ep_resume_napi_irqs(struct eventpoll *ep) +{ +} + #endif /* CONFIG_NET_RX_BUSY_POLL */ =20 /* @@ -788,6 +814,7 @@ static bool ep_refcount_dec_and_test(struct eventpoll *= ep) =20 static void ep_free(struct eventpoll *ep) { + ep_resume_napi_irqs(ep); mutex_destroy(&ep->mtx); free_uid(ep->user); wakeup_source_unregister(ep->ws); @@ -2005,8 +2032,10 @@ static int ep_poll(struct eventpoll *ep, struct epol= l_event __user *events, * trying again in search of more luck. */ res =3D ep_send_events(ep, events, maxevents); - if (res) + if (res) { + ep_suspend_napi_irqs(ep); return res; + } } =20 if (timed_out) --=20 2.25.1