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Wed, 4 Nov 2026 19:56:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793822207; bh=9vYsQ2z6p4kEQ26Jb8WOubzMzQn6P43ATzZz2gRYd8s=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=e2uxiHuxfEJdhmjLozO9LVNrgHWWCvyZHjL6HCg7amaM22yI9yG0olu1uJ96j73/Z xTQNcQbMhTyIG8P3vbMDLmuT2phtFdMJBnVFMbLXmKKNtZbqq02BRamAUB44uazdL3 urCr5eyZbIruy/giy8yhCYSK2FnSUIzF0uuLJu8guQkWA1W37endcFSgwzxgmXgdpv WgWqivOuiipmtpXNrqJUTWyUBgi0SwINwwt/Cqe2dz7mNJDn9EIm/pVofRmhuImUVo H8QqbrQNf9HFXNZ1hUfz4Fw5j+PPHT9mjrfkR6KYflVEzz/AoZKdc8Eb+kMcDaWwM1 H1CvOEcsSWIHA== From: Christian Brauner To: linux-fsdevel@vger.kernel.org Cc: Linus Torvalds , Jann Horn , Josef Bacik , Chris Mason , Jeff Layton , NeilBrown , Eric Dumazet , Thomas Gleixner , Al Viro , Jonathan Corbet , Christoph Hellwig , Greg Kroah-Hartman , Joel Granados , Kees Cook , Jan Kara , Jan Kara , linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-acpi@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-s390@vger.kernel.org, linux-scsi@vger.kernel.org, linux-um@lists.infradead.org, linux-wireless@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, netdev@vger.kernel.org, ntfs3@lists.linux.dev, platform-driver-x86@vger.kernel.org, coreteam@netfilter.org, kexec@lists.infradead.org, linux-pci@vger.kernel.org, linux-sound@vger.kernel.org, netfilter-devel@vger.kernel.org, dri-devel@lists.freedesktop.org, ibm-acpi-devel@lists.sourceforge.net, jfs-discussion@lists.sourceforge.net, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-cifs@vger.kernel.org, linux-fbdev@vger.kernel.org, linux-hwmon@vger.kernel.org, linux-mm@kvack.org, linux-sh@vger.kernel.org, linux-usb@vger.kernel.org, samba-technical@lists.samba.org, sparclinux@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-doc@vger.kernel.org, linux-serial@vger.kernel.org, linux-atm-general@lists.sourceforge.net, Takashi Iwai , linux-input@vger.kernel.org, linux-raid@vger.kernel.org, linux-ext4@vger.kernel.org, linux-modules@vger.kernel.org, linux-debuggers@vger.kernel.org, "Christian Brauner (Amutable)" , Chuck Lever Subject: [PATCH RESEND v2 28/30] mm/swapfile: let procfs own the wait queue of /proc/swaps Date: Wed, 4 Nov 2026 20:56:33 +0100 Message-ID: <20261104-work-procfs-fs-v2-28-319e0f9a8aae@kernel.org> In-Reply-To: <20261104-work-procfs-fs-v2-0-319e0f9a8aae@kernel.org> References: <20261104-work-procfs-fs-v2-0-319e0f9a8aae@kernel.org> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" X-Mailer: b4 0.17-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=2019; i=brauner@kernel.org; h=from:subject:message-id; bh=VLC7S5nkyALdZiiw9586D7569GKKbKISIa7jUul9ZSQ=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMWS97vEV3KXoYc6wwNTta5J2SbyikafkWx/po6m7FWtOr PLmcCroKGVhEONikBVTZHFoNwmXW85TsdkoUwNmDisTyBAGLk4BmMhMA4Z/KivFpjxV2sx0std/ mh+/+VeZnyvk60UXbOG53vWE+fLyG4wMk7fu+rgnv6JzYR1H2t24xj6e5tmlRd9mX90acdHdM9y RDwA= X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Content-Transfer-Encoding: 8bit X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-um" X-Spam-Status: No, score=-18.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 swaps_poll() sleeps the poller on a queue of its own. procfs owns the queue poll() uses now, so leave the poll_wait() to it and wake its pollers when a swap area comes or goes. Signed-off-by: Christian Brauner (Amutable) --- mm/swapfile.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/mm/swapfile.c b/mm/swapfile.c index ee4868ecc3a7..1d063a1cef43 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -111,7 +111,7 @@ static struct kmem_cache *swap_table_cachep; /* Protects si->swap_file for /proc/swaps usage */ static DEFINE_MUTEX(swapon_mutex); -static DECLARE_WAIT_QUEUE_HEAD(proc_poll_wait); +static struct proc_dir_entry *proc_swaps; /* Activity counter to indicate that a swapon or swapoff has occurred */ static atomic_t proc_poll_event = ATOMIC_INIT(0); @@ -3307,7 +3307,7 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile) err = 0; atomic_inc(&proc_poll_event); - wake_up_interruptible(&proc_poll_wait); + proc_poll_notify(proc_swaps); out_dput: filp_close(victim, NULL); @@ -3319,8 +3319,6 @@ static __poll_t swaps_poll(struct file *file, poll_table *wait) { struct seq_file *seq = file->private_data; - poll_wait(file, &proc_poll_wait, wait); - if (seq->poll_event != atomic_read(&proc_poll_event)) { seq->poll_event = atomic_read(&proc_poll_event); return EPOLLIN | EPOLLRDNORM | EPOLLERR | EPOLLPRI; @@ -3428,7 +3426,7 @@ static const struct proc_ops swaps_proc_ops = { static int __init procswaps_init(void) { - proc_create("swaps", 0, NULL, &swaps_proc_ops); + proc_swaps = proc_create("swaps", 0, NULL, &swaps_proc_ops); return 0; } __initcall(procswaps_init); @@ -3907,7 +3905,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) mutex_unlock(&swapon_mutex); atomic_inc(&proc_poll_event); - wake_up_interruptible(&proc_poll_wait); + proc_poll_notify(proc_swaps); error = 0; goto out; -- 2.53.0