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b=Tl7/Br9r01iHEBaBIVHmGqZfuDwsnmz2afTYicmtxxNa6k0nRAINIxKRTLmbWaM5y 9EqRpg1QaEuJ3LknjWRWIDGuBnb9s25158SuDmf0xp9UMsYXVnkdVTnilrFX04FrcE sUQYP0cjKX/eKWotlEEoUN+waZuyjJAVdVW/h6OWPtrA3VCGtisK57ioKaSj46kDvF Y8hxeR4ciM6fHhCQhU3TpBPiiSY0cbPoo7fP5OauL48vG2q/hv8ydG4gemfK526eSA BhgV7kKdlnonPzxIVsYFu2kNWfnIjZcq4SHPDLzP5YLJs9daMS5eVmbpez6QkYgj7p xZankSgOwoVmQ== From: SeongJae Park To: Andrew Morton Cc: SeongJae Park , damon@lists.linux.dev, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 2/5] mm/damon/sysfs: use damon_kdamond_pid() Date: Thu, 15 Jan 2026 07:20:42 -0800 Message-ID: <20260115152047.68415-3-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260115152047.68415-1-sj@kernel.org> References: <20260115152047.68415-1-sj@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 6963EC0004 X-Rspam-User: X-Stat-Signature: 4dtqqcitsf3mb58pgkh5jadbp1i3ojqj X-HE-Tag: 1768490454-189732 X-HE-Meta: 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 OKbHwOux Y8DPmnw1M6mnf/0UN8PM8dX2//iEm50fniDRkIovcGFkzBQKxfDKFkjS3pDvDlc7tKLQTSudzuut5nQS4FlIVd14l3Uv7z67lC04wMGSdwfLZ7IbDFNQ453CkI2tlOBPkbYfPeEd/692O0L0yC76wMVVqmJhq5Znrxwxkot8q13So2z6z07DezV5UxktP345vt2rvZL8ySC515UZswsadNtRlbJ4XtG82MP1a3ayQS1IIGy02lTIxBz7ySqDjys/xi33OjHcf76YCsjF6RdkHclYfFmvgP/6ymiNAXueQ4w6IvZ8= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: DAMON sysfs interface directly uses damon_ctx->kdamond field with manual synchronization using damon_ctx->kdamond_lock, to get the pid of the kdamond. Use a new dedicated function for the purpose, namely damon_kdamond_pid(), since that doesn't require manual and error-prone synchronization. Avoid use of kdamond_lock outside of the core. Signed-off-by: SeongJae Park --- mm/damon/sysfs.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c index 95fd9375a7d8..4de25708b05a 100644 --- a/mm/damon/sysfs.c +++ b/mm/damon/sysfs.c @@ -1819,10 +1819,9 @@ static ssize_t pid_show(struct kobject *kobj, if (!ctx) goto out; - mutex_lock(&ctx->kdamond_lock); - if (ctx->kdamond) - pid = ctx->kdamond->pid; - mutex_unlock(&ctx->kdamond_lock); + pid = damon_kdamond_pid(ctx); + if (pid < 0) + pid = -1; out: mutex_unlock(&damon_sysfs_lock); return sysfs_emit(buf, "%d\n", pid); -- 2.47.3