From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out162-62-58-216.mail.qq.com (out162-62-58-216.mail.qq.com [162.62.58.216]) (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 3CABB199DC; Mon, 15 Jan 2024 20:42:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=foxmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=foxmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=foxmail.com header.i=@foxmail.com header.b="Ug9FFR/K" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foxmail.com; s=s201512; t=1705351332; bh=0GZMuy83Qkf0CT/wQsE+OjcK1LFAZ6r3ajEM94ed9LM=; h=From:To:Cc:Subject:Date; b=Ug9FFR/KsLbVoL5B811EdsJ/O1Zm6j1L9J0D1ecV4MZKvKLvqbMMJn5OuuThujw6k mObChAZmRLKX7Az1jtOIH5gBZWPvT9lU4cf2vLqVasOpbFeKJNS2zzAGmdlaHXbfq9 V3NkTFqjeIBPie+58H1P4DckWWMDe9XtucoW3FxM= Received: from localhost.localdomain ([2409:8a60:2a63:2f30:a63a:c84e:620:9928]) by newxmesmtplogicsvrszc5-2.qq.com (NewEsmtp) with SMTP id 6CEB9CA0; Mon, 15 Jan 2024 23:27:14 +0800 X-QQ-mid: xmsmtpt1705332434ty7d94vs3 Message-ID: X-QQ-XMAILINFO: OZsapEVPoiO6cs2bsyymhyvFqUuhCAPk9ul8rNUG4VgNtxtY0dH5g0uBkpcTsB Xht6BF+QP6s/SL7G30S5jJjmR9o9pGVmdbyo0afFDoykRUnsEIRuL/slsLeyxIsSMcSpSRJK9nsa BGOIcuOBVl0f8IjUpdQidRA2UVg7Jcc/fMhtNUYkq4v8IkhJGn2++cmIX1kANYAgqumj6aiArSQi spHPN5Bsa+kzRM2OsW65efjjbaoSE7yIvQ67OfC3jhn/loPgArhha3ZanBxWUbijIl/7t40PO+xI cyWe/Esj80/zuIQ4cAgOjMvZgMIb+FfHLjHCoeDFXk8ou5mGPwa2jjN+5WGE/UoKtSZ/ZYFjD/GI /hq9Pzp0YU7IkC1HZLLI9wZN6KpSJqotegBefXd6GBgQbF7eMGTD/BrTqGfACRAPoH+IkbXMXTMG JmOVE6WmtbmFKfDSXUdTzvVWWQmJa5YUhTQop0dn5jmRQQ1/BWDR4LlttoaBIhJdUKyO2L1eLOW1 ZtnDQrySnyr3Opx4GNpUE76ruKiXMGVHbGGNyl9gvKNIhgSCyx9c+jJfVCP8p+csJjTmnDYeeXmu TufLAOGpht3SEYSeWGi9i73wh2rKk93v/ipkSuO3syhB0hy7fkgeMWUDAHWMOGOCr20QLV9+/g+K 2sONJK53otXGWAG39h+cq+Q36Hxnjz1tE4Xw8jF363dsUql1p3KY8Z/FJqlRJsCPfZ6nmjYn+gka G4TndEWzv3wMPbhgwC/NpNiDU6vNC9t8nBkcIhBmjSE6S/+HZcvaumWTCwLklRPZl/ukMsNmNA77 gleYm58lShb6aW6HckH1eZmQspSiu+Y404pzf0R+A1SKTaF1p7Z1yZs27XmvTRTkByd1RAspEmO7 dNEXFz4NInc0Uxxt7vCPwLIzjd6O20lXL+22MrbZfGD1wBhRX/QydfetnLSTsHhJnmQBK+L+l3Eh xJox79qv8uVd9ClDyzaRkpQtw8Lq6GCvKEINwtUeoOp7goGQbQZ57E3QSaHz1HJQUXO2+EPckXm0 PIx4CMkr9TNZVs54qr X-QQ-XMRINFO: NyFYKkN4Ny6FSmKK/uo/jdU= From: wenyang.linux@foxmail.com To: Christian Brauner , Jens Axboe , Alexander Viro Cc: Wen Yang , Christoph Hellwig , Dylan Yudaken , David Woodhouse , Matthew Wilcox , Eric Biggers , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3] eventfd: move 'eventfd-count' printing out of spinlock Date: Mon, 15 Jan 2024 23:27:00 +0800 X-OQ-MSGID: <20240115152700.9478-1-wenyang.linux@foxmail.com> X-Mailer: git-send-email 2.25.1 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Wen Yang When printing eventfd->count, interrupts will be disabled and a spinlock will be obtained, competing with eventfd_write(). By moving the "eventfd-count" print out of the spinlock and merging multiple seq_printf() into one, it could improve a bit, just like timerfd_show(). Signed-off-by: Wen Yang Cc: Alexander Viro Cc: Jens Axboe Cc: Christian Brauner Cc: Christoph Hellwig Cc: Dylan Yudaken Cc: David Woodhouse Cc: Matthew Wilcox Cc: Eric Biggers Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- fs/eventfd.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/fs/eventfd.c b/fs/eventfd.c index ad8186d47ba7..a6fa6ee748df 100644 --- a/fs/eventfd.c +++ b/fs/eventfd.c @@ -283,13 +283,18 @@ static ssize_t eventfd_write(struct file *file, const char __user *buf, size_t c static void eventfd_show_fdinfo(struct seq_file *m, struct file *f) { struct eventfd_ctx *ctx = f->private_data; + unsigned long long cnt; spin_lock_irq(&ctx->wqh.lock); - seq_printf(m, "eventfd-count: %16llx\n", - (unsigned long long)ctx->count); + cnt = ctx->count; spin_unlock_irq(&ctx->wqh.lock); - seq_printf(m, "eventfd-id: %d\n", ctx->id); - seq_printf(m, "eventfd-semaphore: %d\n", + + seq_printf(m, + "eventfd-count: %16llx\n" + "eventfd-id: %d\n" + "eventfd-semaphore: %d\n", + cnt, + ctx->id, !!(ctx->flags & EFD_SEMAPHORE)); } #endif -- 2.25.1