Re: [PATCH 1/2] kexec: add a dummy note for each offline cpu

2016-12-15 Thread Liu ping fan
On Thu, Dec 15, 2016 at 3:16 PM, Dave Young wrote: > Hi, Pingfan > On 12/14/16 at 02:11pm, Pingfan Liu wrote: >> kexec-tools always allocates program headers for each possible cpu. This >> incurs zero PT_NOTE for offline cpu. We mark this case so that later, >> the capture

Re: [PATCH 1/2] kexec: add a dummy note for each offline cpu

2016-12-14 Thread Dave Young
Hi, Pingfan On 12/14/16 at 02:11pm, Pingfan Liu wrote: > kexec-tools always allocates program headers for each possible cpu. This > incurs zero PT_NOTE for offline cpu. We mark this case so that later, > the capture kernel can distinguish it from the mistake of allocated > program header. > The

Re: [PATCH 1/2] kexec: add a dummy note for each offline cpu

2016-12-14 Thread Xunlei Pang
On 12/14/2016 at 05:13 PM, Liu ping fan wrote: > [...] >>> No. This patch just place a mark on these offline cpu. The next patch >>> for capture kernel will recognize this case, and ignore this kind of >>> pt_note by the code: >>> real_sz = 0; // although the size of this kind of PT_NOTE is not

Re: [PATCH 1/2] kexec: add a dummy note for each offline cpu

2016-12-14 Thread Liu ping fan
[...] >>> >> No. This patch just place a mark on these offline cpu. The next patch >> for capture kernel will recognize this case, and ignore this kind of >> pt_note by the code: >> real_sz = 0; // although the size of this kind of PT_NOTE is not zero, >> but it contains nothing useful, so just

Re: [PATCH 1/2] kexec: add a dummy note for each offline cpu

2016-12-14 Thread Xunlei Pang
On 12/14/2016 at 04:56 PM, Liu ping fan wrote: > On Wed, Dec 14, 2016 at 4:48 PM, Xunlei Pang wrote: >> On 12/14/2016 at 02:11 PM, Pingfan Liu wrote: >>> kexec-tools always allocates program headers for each possible cpu. This >>> incurs zero PT_NOTE for offline cpu. We mark

Re: [PATCH 1/2] kexec: add a dummy note for each offline cpu

2016-12-14 Thread Liu ping fan
[...] >> >> > >> >> > When you execute dmesg on your testing machine and grep nr_cpu_ids, >> >> > what's the value of nr_cpu_ids? >> >> > >> >> nr_cpu_ids=128 >> > >> > And what's the cpu number of in "lscpu" command? >> >> NUMA node1 CPU(s): 0-7 >> >> The system booted up with 128 possible

Re: [PATCH 1/2] kexec: add a dummy note for each offline cpu

2016-12-14 Thread Liu ping fan
On Wed, Dec 14, 2016 at 4:48 PM, Xunlei Pang wrote: > On 12/14/2016 at 02:11 PM, Pingfan Liu wrote: >> kexec-tools always allocates program headers for each possible cpu. This >> incurs zero PT_NOTE for offline cpu. We mark this case so that later, >> the capture kernel can

Re: [PATCH 1/2] kexec: add a dummy note for each offline cpu

2016-12-14 Thread Xunlei Pang
On 12/14/2016 at 02:11 PM, Pingfan Liu wrote: > kexec-tools always allocates program headers for each possible cpu. This > incurs zero PT_NOTE for offline cpu. We mark this case so that later, > the capture kernel can distinguish it from the mistake of allocated > program header. > The counterpart

Re: [PATCH 1/2] kexec: add a dummy note for each offline cpu

2016-12-14 Thread Baoquan He
On 12/14/16 at 04:39pm, Liu ping fan wrote: > On Wed, Dec 14, 2016 at 4:25 PM, Baoquan He wrote: > > On 12/14/16 at 04:15pm, Liu ping fan wrote: > >> On Wed, Dec 14, 2016 at 3:40 PM, Baoquan He wrote: > >> > On 12/14/16 at 02:11pm, Pingfan Liu wrote: > >> >>

Re: [PATCH 1/2] kexec: add a dummy note for each offline cpu

2016-12-14 Thread Liu ping fan
On Wed, Dec 14, 2016 at 4:25 PM, Baoquan He wrote: > On 12/14/16 at 04:15pm, Liu ping fan wrote: >> On Wed, Dec 14, 2016 at 3:40 PM, Baoquan He wrote: >> > On 12/14/16 at 02:11pm, Pingfan Liu wrote: >> >> kexec-tools always allocates program headers for each

Re: [PATCH 1/2] kexec: add a dummy note for each offline cpu

2016-12-14 Thread Baoquan He
On 12/14/16 at 04:15pm, Liu ping fan wrote: > On Wed, Dec 14, 2016 at 3:40 PM, Baoquan He wrote: > > On 12/14/16 at 02:11pm, Pingfan Liu wrote: > >> kexec-tools always allocates program headers for each possible cpu. This > >> incurs zero PT_NOTE for offline cpu. We mark this

Re: [PATCH 1/2] kexec: add a dummy note for each offline cpu

2016-12-14 Thread Liu ping fan
On Wed, Dec 14, 2016 at 3:40 PM, Baoquan He wrote: > On 12/14/16 at 02:11pm, Pingfan Liu wrote: >> kexec-tools always allocates program headers for each possible cpu. This >> incurs zero PT_NOTE for offline cpu. We mark this case so that later, >> the capture kernel can

Re: [PATCH 1/2] kexec: add a dummy note for each offline cpu

2016-12-13 Thread Baoquan He
On 12/14/16 at 02:11pm, Pingfan Liu wrote: > kexec-tools always allocates program headers for each possible cpu. This > incurs zero PT_NOTE for offline cpu. We mark this case so that later, > the capture kernel can distinguish it from the mistake of allocated > program header. > The counterpart of

Re: [PATCH 1/2] kexec: add a dummy note for each offline cpu

2016-12-13 Thread Liu ping fan
On Wed, Dec 14, 2016 at 2:11 PM, Pingfan Liu wrote: > kexec-tools always allocates program headers for each possible cpu. This The code is in the file:kexec-tools/kexec/crashdump-elf.c nr_cpus = sysconf(_SC_NPROCESSORS_CONF); > incurs zero PT_NOTE for offline cpu. We

[PATCH 1/2] kexec: add a dummy note for each offline cpu

2016-12-13 Thread Pingfan Liu
kexec-tools always allocates program headers for each possible cpu. This incurs zero PT_NOTE for offline cpu. We mark this case so that later, the capture kernel can distinguish it from the mistake of allocated program header. The counterpart of the capture kernel comes in next patch.