From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga02-in.huawei.com ([119.145.14.65]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Y3kng-0003pO-Ab for linux-mtd@lists.infradead.org; Wed, 24 Dec 2014 12:12:25 +0000 Message-ID: <549AAD57.8020307@huawei.com> Date: Wed, 24 Dec 2014 20:11:03 +0800 From: hujianyang MIME-Version: 1.0 To: Artem Bityutskiy Subject: ubi_check_volume() hung on a single core system Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Cc: Richard Weinberger , linux-mtd List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi, When I was running mtd-utils/tests/ubi-tests/io_basic.c on a single core system, watchdog reset the OS and printed: ERR:The task of feeding senior watchdog overtimes, system will reset! io_basic.c tests the UBI_IOCVOLUP feature of UBI driver. UBI will perform ubi_check_volume() after updating operation is finished. The used ebs will be scanned for a static volume in this function. If I run schedule() in the loop of eraseblock scanning, the *reset* not happen and the system works in right condition. diff --git a/drivers/mtd/ubi/misc.c b/drivers/mtd/ubi/misc.c index dbda77e..f4f478c 100644 --- a/drivers/mtd/ubi/misc.c +++ b/drivers/mtd/ubi/misc.c @@ -74,6 +74,9 @@ int ubi_check_volume(struct ubi_device *ubi, int vol_id) for (i = 0; i < vol->used_ebs; i++) { int size; + set_current_state(TASK_UNINTERRUPTIBLE); + schedule_timeout(HZ/10); + if (i == vol->used_ebs - 1) size = vol->last_eb_bytes; else I think this error can't be re-created on a multi-core system. It can only happen on a single core system. This directly schedule I modified would hurt the performance of volume check. Does anyone interested in this issue? Thanks, Hu