From: Petr Mladek <pmladek@suse.com> To: Dave Young <dyoung@redhat.com> Cc: sergey.senozhatsky@gmail.com, rostedt@goodmis.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, kexec@lists.infradead.org Subject: Re: [PATCH] print kdump kernel loaded status in stack dump Date: Wed, 17 Jan 2018 14:42:17 +0100 [thread overview] Message-ID: <20180117134217.6gjr5ep3g2ns2v3w@pathway.suse.cz> (raw) In-Reply-To: <20180117123244.GA1503@dhcp-128-65.nay.redhat.com> On Wed 2018-01-17 20:32:44, Dave Young wrote: > Hi, > > Thanks for your comments. > On 01/17/18 at 09:57am, Petr Mladek wrote: > > On Wed 2018-01-17 12:50:57, Dave Young wrote: > > > It is useful to print kdump kernel loaded status in dump_stack() > > > especially when panic happens so that we can differenciate > > > kdump kernel early hang and a normal panic in a bug report. > > > > > > Signed-off-by: Dave Young <dyoung@redhat.com> > > > --- > > > kernel/printk/printk.c | 3 +++ > > > 1 file changed, 3 insertions(+) > > > > > > --- linux-x86.orig/kernel/printk/printk.c > > > +++ linux-x86/kernel/printk/printk.c > > > @@ -48,6 +48,7 @@ > > > #include <linux/sched/clock.h> > > > #include <linux/sched/debug.h> > > > #include <linux/sched/task_stack.h> > > > +#include <linux/kexec.h> > > > > > > #include <linux/uaccess.h> > > > #include <asm/sections.h> > > > @@ -3127,6 +3128,8 @@ void dump_stack_print_info(const char *l > > > if (dump_stack_arch_desc_str[0] != '\0') > > > printk("%sHardware name: %s\n", > > > log_lvl, dump_stack_arch_desc_str); > > > + if (kexec_crash_loaded()) > > > + printk("%skdump kernel loaded\n", log_lvl); > > > > IMHO, it would be better to do it like for the workqueues. > > I mean to call printk_kexec_info(log_lv1, current) here > > that would be impletemented in kexec sources. > > Then it could be maintained by kexec people. > > > > Anyway, I wonder if the info about kexec_crash_loaded() is > > enough. I am not much familiar with kexec. AFAIK, > > the image might be loaded long time before it > > is acutally used. > > kexec_crash_loaded is enough, we only care if kdump kernel being > loaded or not, nothing else, no matter how long it has been loaded. > In Fedora/RHEL a kdump service takes care of loading the kernel but > it runs after networking is ready. If people want to save > the vmcore to nfs/ssh then we need detect network and build the > initramfs. In the nfs/ssh case if some networking code panicked it > is possible that kdump service has not started, but sometimes bug > can not be easily reproduced thus nobody can know if kdump is active > or not. I see. > Since kexec_crash_loaded() is already in kexec souce code, and it > is the only thing need to know, do you think it is really necessary > to add a printk_kexec_info()? I can do it if you strongly suggest > to do so. No, the original approach is fine if it is really that simple ;-) > > > > Finally, the style of the other lines is: > > > > Name: details > > > > I would suggest to print something like: > > > > Kexec: details > > > > , where the details might be whether the image is loaded, > > whether the loaded kernel is being executed, and > > other kexec-related flags. > > Will do, it can be something like: > Kexec: kdump kernel loaded Looks good to me. With this message, I could give this patch even Reviewed-by: Petr Mladek <pmladek@suse.com> I could update the string when pushing into printk.git. I am just going to wait a bit for more feedback if any. Best Regards, Petr
WARNING: multiple messages have this Message-ID (diff)
From: Petr Mladek <pmladek@suse.com> To: Dave Young <dyoung@redhat.com> Cc: sergey.senozhatsky@gmail.com, akpm@linux-foundation.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, rostedt@goodmis.org Subject: Re: [PATCH] print kdump kernel loaded status in stack dump Date: Wed, 17 Jan 2018 14:42:17 +0100 [thread overview] Message-ID: <20180117134217.6gjr5ep3g2ns2v3w@pathway.suse.cz> (raw) In-Reply-To: <20180117123244.GA1503@dhcp-128-65.nay.redhat.com> On Wed 2018-01-17 20:32:44, Dave Young wrote: > Hi, > > Thanks for your comments. > On 01/17/18 at 09:57am, Petr Mladek wrote: > > On Wed 2018-01-17 12:50:57, Dave Young wrote: > > > It is useful to print kdump kernel loaded status in dump_stack() > > > especially when panic happens so that we can differenciate > > > kdump kernel early hang and a normal panic in a bug report. > > > > > > Signed-off-by: Dave Young <dyoung@redhat.com> > > > --- > > > kernel/printk/printk.c | 3 +++ > > > 1 file changed, 3 insertions(+) > > > > > > --- linux-x86.orig/kernel/printk/printk.c > > > +++ linux-x86/kernel/printk/printk.c > > > @@ -48,6 +48,7 @@ > > > #include <linux/sched/clock.h> > > > #include <linux/sched/debug.h> > > > #include <linux/sched/task_stack.h> > > > +#include <linux/kexec.h> > > > > > > #include <linux/uaccess.h> > > > #include <asm/sections.h> > > > @@ -3127,6 +3128,8 @@ void dump_stack_print_info(const char *l > > > if (dump_stack_arch_desc_str[0] != '\0') > > > printk("%sHardware name: %s\n", > > > log_lvl, dump_stack_arch_desc_str); > > > + if (kexec_crash_loaded()) > > > + printk("%skdump kernel loaded\n", log_lvl); > > > > IMHO, it would be better to do it like for the workqueues. > > I mean to call printk_kexec_info(log_lv1, current) here > > that would be impletemented in kexec sources. > > Then it could be maintained by kexec people. > > > > Anyway, I wonder if the info about kexec_crash_loaded() is > > enough. I am not much familiar with kexec. AFAIK, > > the image might be loaded long time before it > > is acutally used. > > kexec_crash_loaded is enough, we only care if kdump kernel being > loaded or not, nothing else, no matter how long it has been loaded. > In Fedora/RHEL a kdump service takes care of loading the kernel but > it runs after networking is ready. If people want to save > the vmcore to nfs/ssh then we need detect network and build the > initramfs. In the nfs/ssh case if some networking code panicked it > is possible that kdump service has not started, but sometimes bug > can not be easily reproduced thus nobody can know if kdump is active > or not. I see. > Since kexec_crash_loaded() is already in kexec souce code, and it > is the only thing need to know, do you think it is really necessary > to add a printk_kexec_info()? I can do it if you strongly suggest > to do so. No, the original approach is fine if it is really that simple ;-) > > > > Finally, the style of the other lines is: > > > > Name: details > > > > I would suggest to print something like: > > > > Kexec: details > > > > , where the details might be whether the image is loaded, > > whether the loaded kernel is being executed, and > > other kexec-related flags. > > Will do, it can be something like: > Kexec: kdump kernel loaded Looks good to me. With this message, I could give this patch even Reviewed-by: Petr Mladek <pmladek@suse.com> I could update the string when pushing into printk.git. I am just going to wait a bit for more feedback if any. Best Regards, Petr _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
next prev parent reply other threads:[~2018-01-17 13:42 UTC|newest] Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-01-17 4:50 [PATCH] print kdump kernel loaded status in stack dump Dave Young 2018-01-17 4:50 ` Dave Young 2018-01-17 8:57 ` Petr Mladek 2018-01-17 8:57 ` Petr Mladek 2018-01-17 12:32 ` Dave Young 2018-01-17 12:32 ` Dave Young 2018-01-17 13:42 ` Petr Mladek [this message] 2018-01-17 13:42 ` Petr Mladek 2018-01-17 15:48 ` Steven Rostedt 2018-01-17 15:48 ` Steven Rostedt 2018-01-18 1:57 ` Dave Young 2018-01-18 1:57 ` Dave Young 2018-01-18 18:02 ` Andi Kleen 2018-01-18 18:02 ` Andi Kleen 2018-01-18 18:57 ` Steven Rostedt 2018-01-18 18:57 ` Steven Rostedt 2018-01-19 4:47 ` Dave Young 2018-01-19 4:47 ` Dave Young 2018-01-19 13:06 ` Petr Tesarik 2018-01-26 7:37 ` Dave Young 2018-01-26 7:37 ` Dave Young 2018-01-26 12:17 ` Petr Mladek 2018-01-26 12:17 ` Petr Mladek 2018-01-27 3:57 ` Dave Young 2018-01-27 3:57 ` Dave Young 2018-01-19 5:45 ` Sergey Senozhatsky 2018-01-19 5:45 ` Sergey Senozhatsky 2018-01-19 8:16 ` Dave Young 2018-01-19 8:16 ` Dave Young 2018-01-19 8:28 ` Sergey Senozhatsky 2018-01-19 8:28 ` Sergey Senozhatsky 2018-01-19 8:42 ` Dave Young 2018-01-19 8:42 ` Dave Young 2018-01-19 9:46 ` Sergey Senozhatsky 2018-01-19 9:46 ` Sergey Senozhatsky 2018-01-19 8:32 ` Sergey Senozhatsky 2018-01-19 8:32 ` Sergey Senozhatsky 2018-01-19 16:16 ` Andi Kleen 2018-01-19 16:16 ` Andi Kleen 2018-01-19 16:51 ` Petr Tesarik
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