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([2a0b:e7c0:0:107::aaaa:59]) by smtp.gmail.com with ESMTPSA id v8-20020a1709067d8800b00a45aeaf9969sm4518500ejo.5.2024.03.12.22.58.57 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 12 Mar 2024 22:58:58 -0700 (PDT) Message-ID: <2f8b1b2d-0abb-43f0-8665-0855928f017c@kernel.org> Date: Wed, 13 Mar 2024 06:58:57 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: kexec verbose dumps with 6.8 [was: [PATCH v4 1/7] kexec_file: add kexec_file flag to control debug printing] Content-Language: en-US To: Baoquan He References: <20231213055747.61826-1-bhe@redhat.com> <20231213055747.61826-2-bhe@redhat.com> <4c775fca-5def-4a2d-8437-7130b02722a2@kernel.org> From: Jiri Slaby Autocrypt: addr=jirislaby@kernel.org; keydata= xsFNBE6S54YBEACzzjLwDUbU5elY4GTg/NdotjA0jyyJtYI86wdKraekbNE0bC4zV+ryvH4j rrcDwGs6tFVrAHvdHeIdI07s1iIx5R/ndcHwt4fvI8CL5PzPmn5J+h0WERR5rFprRh6axhOk rSD5CwQl19fm4AJCS6A9GJtOoiLpWn2/IbogPc71jQVrupZYYx51rAaHZ0D2KYK/uhfc6neJ i0WqPlbtIlIrpvWxckucNu6ZwXjFY0f3qIRg3Vqh5QxPkojGsq9tXVFVLEkSVz6FoqCHrUTx wr+aw6qqQVgvT/McQtsI0S66uIkQjzPUrgAEtWUv76rM4ekqL9stHyvTGw0Fjsualwb0Gwdx ReTZzMgheAyoy/umIOKrSEpWouVoBt5FFSZUyjuDdlPPYyPav+hpI6ggmCTld3u2hyiHji2H cDpcLM2LMhlHBipu80s9anNeZhCANDhbC5E+NZmuwgzHBcan8WC7xsPXPaiZSIm7TKaVoOcL 9tE5aN3jQmIlrT7ZUX52Ff/hSdx/JKDP3YMNtt4B0cH6ejIjtqTd+Ge8sSttsnNM0CQUkXps w98jwz+Lxw/bKMr3NSnnFpUZaxwji3BC9vYyxKMAwNelBCHEgS/OAa3EJoTfuYOK6wT6nadm YqYjwYbZE5V/SwzMbpWu7Jwlvuwyfo5mh7w5iMfnZE+vHFwp/wARAQABzSFKaXJpIFNsYWJ5 IDxqaXJpc2xhYnlAa2VybmVsLm9yZz7CwXcEEwEIACEFAlW3RUwCGwMFCwkIBwIGFQgJCgsC BBYCAwECHgECF4AACgkQvSWxBAa0cEnVTg//TQpdIAr8Tn0VAeUjdVIH9XCFw+cPSU+zMSCH eCZoA/N6gitEcnvHoFVVM7b3hK2HgoFUNbmYC0RdcSc80pOF5gCnACSP9XWHGWzeKCARRcQR 4s5YD8I4VV5hqXcKo2DFAtIOVbHDW+0okOzcecdasCakUTr7s2fXz97uuoc2gIBB7bmHUGAH XQXHvdnCLjDjR+eJN+zrtbqZKYSfj89s/ZHn5Slug6w8qOPT1sVNGG+eWPlc5s7XYhT9z66E l5C0rG35JE4PhC+tl7BaE5IwjJlBMHf/cMJxNHAYoQ1hWQCKOfMDQ6bsEr++kGUCbHkrEFwD UVA72iLnnnlZCMevwE4hc0zVhseWhPc/KMYObU1sDGqaCesRLkE3tiE7X2cikmj/qH0CoMWe gjnwnQ2qVJcaPSzJ4QITvchEQ+tbuVAyvn9H+9MkdT7b7b2OaqYsUP8rn/2k1Td5zknUz7iF oJ0Z9wPTl6tDfF8phaMIPISYrhceVOIoL+rWfaikhBulZTIT5ihieY9nQOw6vhOfWkYvv0Dl o4GRnb2ybPQpfEs7WtetOsUgiUbfljTgILFw3CsPW8JESOGQc0Pv8ieznIighqPPFz9g+zSu Ss/rpcsqag5n9rQp/H3WW5zKUpeYcKGaPDp/vSUovMcjp8USIhzBBrmI7UWAtuedG9prjqfO wU0ETpLnhgEQAM+cDWLL+Wvc9cLhA2OXZ/gMmu7NbYKjfth1UyOuBd5emIO+d4RfFM02XFTI t4MxwhAryhsKQQcA4iQNldkbyeviYrPKWjLTjRXT5cD2lpWzr+Jx7mX7InV5JOz1Qq+P+nJW YIBjUKhI03ux89p58CYil24Zpyn2F5cX7U+inY8lJIBwLPBnc9Z0An/DVnUOD+0wIcYVnZAK DiIXODkGqTg3fhZwbbi+KAhtHPFM2fGw2VTUf62IHzV+eBSnamzPOBc1XsJYKRo3FHNeLuS8 f4wUe7bWb9O66PPFK/RkeqNX6akkFBf9VfrZ1rTEKAyJ2uqf1EI1olYnENk4+00IBa+BavGQ 8UW9dGW3nbPrfuOV5UUvbnsSQwj67pSdrBQqilr5N/5H9z7VCDQ0dhuJNtvDSlTf2iUFBqgk 3smln31PUYiVPrMP0V4ja0i9qtO/TB01rTfTyXTRtqz53qO5dGsYiliJO5aUmh8swVpotgK4 /57h3zGsaXO9PGgnnAdqeKVITaFTLY1ISg+Ptb4KoliiOjrBMmQUSJVtkUXMrCMCeuPDGHo7 39Xc75lcHlGuM3yEB//htKjyprbLeLf1y4xPyTeeF5zg/0ztRZNKZicgEmxyUNBHHnBKHQxz 1j+mzH0HjZZtXjGu2KLJ18G07q0fpz2ZPk2D53Ww39VNI/J9ABEBAAHCwV8EGAECAAkFAk6S 54YCGwwACgkQvSWxBAa0cEk3tRAAgO+DFpbyIa4RlnfpcW17AfnpZi9VR5+zr496n2jH/1ld wRO/S+QNSA8qdABqMb9WI4BNaoANgcg0AS429Mq0taaWKkAjkkGAT7mD1Q5PiLr06Y/+Kzdr 90eUVneqM2TUQQbK+Kh7JwmGVrRGNqQrDk+gRNvKnGwFNeTkTKtJ0P8jYd7P1gZb9Fwj9YLx jhn/sVIhNmEBLBoI7PL+9fbILqJPHgAwW35rpnq4f/EYTykbk1sa13Tav6btJ+4QOgbcezWI wZ5w/JVfEJW9JXp3BFAVzRQ5nVrrLDAJZ8Y5ioWcm99JtSIIxXxt9FJaGc1Bgsi5K/+dyTKL wLMJgiBzbVx8G+fCJJ9YtlNOPWhbKPlrQ8+AY52Aagi9WNhe6XfJdh5g6ptiOILm330mkR4g W6nEgZVyIyTq3ekOuruftWL99qpP5zi+eNrMmLRQx9iecDNgFr342R9bTDlb1TLuRb+/tJ98 f/bIWIr0cqQmqQ33FgRhrG1+Xml6UXyJ2jExmlO8JljuOGeXYh6ZkIEyzqzffzBLXZCujlYQ DFXpyMNVJ2ZwPmX2mWEoYuaBU0JN7wM+/zWgOf2zRwhEuD3A2cO2PxoiIfyUEfB9SSmffaK/ S4xXoB6wvGENZ85Hg37C7WDNdaAt6Xh2uQIly5grkgvWppkNy4ZHxE+jeNsU7tg= In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-parisc@vger.kernel.org, x86@kernel.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, conor@kernel.org, nathan@kernel.org, joe@perches.com, linux-riscv@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, akpm@linux-foundation.org, linux-arm-kernel@lists.infradead.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Hi, On 13. 03. 24, 1:48, Baoquan He wrote: > Hi Jiri, > > On 03/12/24 at 10:58am, Jiri Slaby wrote: >> On 13. 12. 23, 6:57, Baoquan He wrote: > ... snip... >>> --- a/include/linux/kexec.h >>> +++ b/include/linux/kexec.h >> ... >>> @@ -500,6 +500,13 @@ static inline int crash_hotplug_memory_support(void) { return 0; } >>> static inline unsigned int crash_get_elfcorehdr_size(void) { return 0; } >>> #endif >>> +extern bool kexec_file_dbg_print; >>> + >>> +#define kexec_dprintk(fmt, ...) \ >>> + printk("%s" fmt, \ >>> + kexec_file_dbg_print ? KERN_INFO : KERN_DEBUG, \ >>> + ##__VA_ARGS__) >> >> This means you dump it _always_. Only with different levels. > > It dumped always too with pr_debug() before, I just add a switch to > control it's pr_info() or pr_debug(). Not really, see below. >> >> And without any prefix whatsoever, so people see bloat like this in their >> log now: >> [ +0.000001] 0000000000001000-000000000009ffff (1) >> [ +0.000002] 000000007f96d000-000000007f97efff (3) >> [ +0.000002] 0000000000800000-0000000000807fff (4) >> [ +0.000001] 000000000080b000-000000000080bfff (4) >> [ +0.000002] 0000000000810000-00000000008fffff (4) >> [ +0.000001] 000000007f97f000-000000007f9fefff (4) >> [ +0.000001] 000000007ff00000-000000007fffffff (4) >> [ +0.000002] 0000000000000000-0000000000000fff (2) > > On which arch are you seeing this? There should be one line above these > range printing to tell what they are, like: > > E820 memmap: Ah this is there too. It's a lot of output, so I took it out of context, apparently. > 0000000000000000-000000000009a3ff (1) > 000000000009a400-000000000009ffff (2) > 00000000000e0000-00000000000fffff (2) > 0000000000100000-000000006ff83fff (1) > 000000006ff84000-000000007ac50fff (2) It should all be prefixed like kdump: or kexec: in any way. >> without actually knowing what that is. >> >> There should be nothing logged if that is not asked for and especially if >> kexec load went fine, right? > > Right. Before this patch, those pr_debug() were already there. You need > enable them to print out like add '#define DEBUG' in *.c file, or enable > the dynamic debugging of the file or function. I think it's perfectly fine for DEBUG builds to print this out. And many (all major?) distros use dyndbg, so it used to print nothing by default. > With this patch applied, > you only need specify '-d' when you execute kexec command with > kexec_file load interface, like: > > kexec -s -l -d /boot/vmlinuz-xxxx.img --initrd xxx.img --reuse-cmdline Perhaps our (SUSE) tooling passes -d? But I am seeing this every time I boot. No, it does not seem so: load.sh[915]: Starting kdump kernel load; kexec cmdline: /sbin/kexec -p /var/lib/kdump/kernel --append=" loglevel=7 console=tty0 console=ttyS0 video=1920x1080,1024x768,800x600 oops=panic lsm=lockdown,capability,integrity,selinux sysrq=yes reset_devices acpi_no_memhotplug cgroup_disable=memory nokaslr numa=off irqpoll nr_cpus=1 root=kdump rootflags=bind rd.udev.children-max=8 disable_cpu_apicid=0 panic=1" --initrd=/var/lib/kdump/initrd -a > For kexec_file load, it is not logging if not specifying '-d', unless > you take way to make pr_debug() work in that file. So is -d detection malfunctioning under some circumstances? >> Can this be redesigned, please? > > Sure, after making clear what's going on with this, I will try. > >> >> Actually what was wrong on the pr_debug()s? Can you simply turn them on from >> the kernel when -d is passed to kexec instead of all this? > > Joe suggested this during v1 reviewing: > https://lore.kernel.org/all/1e7863ec4e4ab10b84fd0e64f30f8464d2e484a3.camel@perches.com/T/#u > >> >> ... >>> --- a/kernel/kexec_core.c >>> +++ b/kernel/kexec_core.c >>> @@ -52,6 +52,8 @@ atomic_t __kexec_lock = ATOMIC_INIT(0); >>> /* Flag to indicate we are going to kexec a new kernel */ >>> bool kexec_in_progress = false; >>> +bool kexec_file_dbg_print; >> >> Ugh, and a global flag for this? > > Yeah, kexec_file_dbg_print records if '-d' is specified when 'kexec' > command executed. Anything wrong with the global flag? Global variables are frowned upon. To cite coding style: unless you **really** need them. Here, it looks like you do not. thanks, -- js suse labs