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[80.230.25.21]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-43fe4e3a7b4sm27168068f8f.22.2026.04.20.05.51.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 20 Apr 2026 05:51:05 -0700 (PDT) Date: Mon, 20 Apr 2026 08:51:03 -0400 From: "Michael S. Tsirkin" To: linux-kernel@vger.kernel.org Cc: Andrew Morton , David Hildenbrand , Vlastimil Babka , Brendan Jackman , Michal Hocko , Suren Baghdasaryan , Jason Wang , Andrea Arcangeli , linux-mm@kvack.org, virtualization@lists.linux.dev, Johannes Weiner , Zi Yan Subject: [PATCH RFC v2 16/18] mm: page_reporting: add flush parameter with page budget Message-ID: <23f8d36128771ded02b426cf71b840500004ca52.1776689093.git.mst@redhat.com> References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Mailer: git-send-email 2.27.0.106.g8ac3dc51b1 X-Mutt-Fcc: =sent Add a write-only module parameter "flush" that triggers immediate page reporting. The value specifies approximately how many pages (at page_reporting_order) to report. The flush loops through reporting cycles until the budget is exhausted, all pages are reported, or a signal is pending. echo 512 > /sys/module/page_reporting/parameters/flush Signed-off-by: Michael S. Tsirkin Assisted-by: Claude:claude-opus-4-6 Assisted-by: cursor-agent:GPT-5.4-xhigh --- mm/page_reporting.c | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) diff --git a/mm/page_reporting.c b/mm/page_reporting.c index 5e1e1a924b0c..3560f272ab70 100644 --- a/mm/page_reporting.c +++ b/mm/page_reporting.c @@ -354,6 +354,48 @@ static void page_reporting_process(struct work_struct *work) static DEFINE_MUTEX(page_reporting_mutex); DEFINE_STATIC_KEY_FALSE(page_reporting_enabled); +static int page_reporting_flush_set(const char *val, + const struct kernel_param *kp) +{ + struct page_reporting_dev_info *prdev; + unsigned int budget; + int err; + + err = kstrtouint(val, 0, &budget); + if (err) + return err; + if (!budget) + return 0; + + mutex_lock(&page_reporting_mutex); + prdev = rcu_dereference_protected(pr_dev_info, + lockdep_is_held(&page_reporting_mutex)); + if (prdev) { + unsigned int reported; + + for (reported = 0; reported < budget; + reported += PAGE_REPORTING_CAPACITY) { + flush_delayed_work(&prdev->work); + __page_reporting_request(prdev); + flush_delayed_work(&prdev->work); + if (atomic_read(&prdev->state) == PAGE_REPORTING_IDLE) + break; + if (signal_pending(current)) + break; + } + } + mutex_unlock(&page_reporting_mutex); + return 0; +} + +static const struct kernel_param_ops flush_ops = { + .set = page_reporting_flush_set, + .get = param_get_uint, +}; +static unsigned int page_reporting_flush; +module_param_cb(flush, &flush_ops, &page_reporting_flush, 0200); +MODULE_PARM_DESC(flush, "Report up to N pages at page_reporting_order"); + int page_reporting_register(struct page_reporting_dev_info *prdev) { int err = 0; -- MST