Re: Qemu master crashing on boot when using file backend for memory
On Tue, 24 Mar 2020 22:50:46 -0400 Raphael Norwitz wrote: > On Thu, Mar 12, 2020 at 11:54:50AM +0100, Igor Mammedov wrote: > > > > On Thu, 12 Mar 2020 01:36:48 -0400 > > Raphael Norwitz wrote: > > > > > When I try run master qemu I am hitting a divide by zero error. It seems > > > to be coming from util/oslib-posix.c in touch_all_pages(). see line 477: > > > > > > numpages_per_thread = numpages / memset_num_threads; > > > > > > Poking around the crash dumps, I can see that the smp_cpus parameter > > > passed in to touch_all_pages() is 0. Going up the stack to > > > host_memory_backend_memory_complete() I see backend->prealloc_threads is > > > also 0. > > > > > > Here’s how I am running qemu > > > > > > ./x86_64-softmmu/qemu-system-x86_64 \ > > > -kernel /boot/vmlinuz-3.10.0-1062.el7.x86_64 \ > > > -netdev user,id=net0,hostfwd=tcp::2250-:22 \ > > > -device e1000e,netdev=net0 \ > > > -m 1G \ > > > -initrd /boot/initramfs-3.10.0-1062.el7.x86_64.img \ > > > -object > > > memory-backend-file,id=ram-node0,prealloc=yes,mem-path=mem,share=yes,size=1G > > > \ > > > -numa node,nodeid=0,cpus=0,memdev=ram-node0 > > > > > > I don't see this error on a slightly older qemu, as of commit 105b07f1 > > > (January 27th). > > > > > > Interestingly when I remove the memory-backend-file parameter I don’t > > > see the error, i.e. this works: > > > > > > ./x86_64-softmmu/qemu-system-x86_64 \ > > > -kernel /boot/vmlinuz-3.10.0-1062.el7.x86_64 \ > > > -netdev user,id=net0,hostfwd=tcp::2250-:22 \ > > > -device e1000e,netdev=net0 \ > > > -m 1G \ > > > -initrd /boot/initramfs-3.10.0-1062.el7.x86_64.img > > > > > > Looking at the blame data for backends/hostmem.c I see commit ffac16fa > > > introduced some churn in this part of the code. Has anyone else seen > > > this issue? Could I be doing something wrong here? > > > > It's know issue, see > > "[PATCH] oslib-posix: initialize mutex and condition variable > > for a fix > > > > > > > I'm testing on qemu master now. Looks like this patch has been merged > and I'm still seeing the same crash. Thanks for report, fix is on the way to qemu-devel
Re: Qemu master crashing on boot when using file backend for memory
On Thu, Mar 12, 2020 at 11:54:50AM +0100, Igor Mammedov wrote: > > On Thu, 12 Mar 2020 01:36:48 -0400 > Raphael Norwitz wrote: > > > When I try run master qemu I am hitting a divide by zero error. It seems > > to be coming from util/oslib-posix.c in touch_all_pages(). see line 477: > > > > numpages_per_thread = numpages / memset_num_threads; > > > > Poking around the crash dumps, I can see that the smp_cpus parameter > > passed in to touch_all_pages() is 0. Going up the stack to > > host_memory_backend_memory_complete() I see backend->prealloc_threads is > > also 0. > > > > Here’s how I am running qemu > > > > ./x86_64-softmmu/qemu-system-x86_64 \ > > -kernel /boot/vmlinuz-3.10.0-1062.el7.x86_64 \ > > -netdev user,id=net0,hostfwd=tcp::2250-:22 \ > > -device e1000e,netdev=net0 \ > > -m 1G \ > > -initrd /boot/initramfs-3.10.0-1062.el7.x86_64.img \ > > -object > > memory-backend-file,id=ram-node0,prealloc=yes,mem-path=mem,share=yes,size=1G > > \ > > -numa node,nodeid=0,cpus=0,memdev=ram-node0 > > > > I don't see this error on a slightly older qemu, as of commit 105b07f1 > > (January 27th). > > > > Interestingly when I remove the memory-backend-file parameter I don’t > > see the error, i.e. this works: > > > > ./x86_64-softmmu/qemu-system-x86_64 \ > > -kernel /boot/vmlinuz-3.10.0-1062.el7.x86_64 \ > > -netdev user,id=net0,hostfwd=tcp::2250-:22 \ > > -device e1000e,netdev=net0 \ > > -m 1G \ > > -initrd /boot/initramfs-3.10.0-1062.el7.x86_64.img > > > > Looking at the blame data for backends/hostmem.c I see commit ffac16fa > > introduced some churn in this part of the code. Has anyone else seen > > this issue? Could I be doing something wrong here? > > It's know issue, see > "[PATCH] oslib-posix: initialize mutex and condition variable > for a fix > > > I'm testing on qemu master now. Looks like this patch has been merged and I'm still seeing the same crash.
Re: Qemu master crashing on boot when using file backend for memory
On Thu, 12 Mar 2020 01:36:48 -0400 Raphael Norwitz wrote: > When I try run master qemu I am hitting a divide by zero error. It seems > to be coming from util/oslib-posix.c in touch_all_pages(). see line 477: > > numpages_per_thread = numpages / memset_num_threads; > > Poking around the crash dumps, I can see that the smp_cpus parameter > passed in to touch_all_pages() is 0. Going up the stack to > host_memory_backend_memory_complete() I see backend->prealloc_threads is > also 0. > > Here’s how I am running qemu > > ./x86_64-softmmu/qemu-system-x86_64 \ > -kernel /boot/vmlinuz-3.10.0-1062.el7.x86_64 \ > -netdev user,id=net0,hostfwd=tcp::2250-:22 \ > -device e1000e,netdev=net0 \ > -m 1G \ > -initrd /boot/initramfs-3.10.0-1062.el7.x86_64.img \ > -object > memory-backend-file,id=ram-node0,prealloc=yes,mem-path=mem,share=yes,size=1G \ > -numa node,nodeid=0,cpus=0,memdev=ram-node0 > > I don't see this error on a slightly older qemu, as of commit 105b07f1 > (January 27th). > > Interestingly when I remove the memory-backend-file parameter I don’t > see the error, i.e. this works: > > ./x86_64-softmmu/qemu-system-x86_64 \ > -kernel /boot/vmlinuz-3.10.0-1062.el7.x86_64 \ > -netdev user,id=net0,hostfwd=tcp::2250-:22 \ > -device e1000e,netdev=net0 \ > -m 1G \ > -initrd /boot/initramfs-3.10.0-1062.el7.x86_64.img > > Looking at the blame data for backends/hostmem.c I see commit ffac16fa > introduced some churn in this part of the code. Has anyone else seen > this issue? Could I be doing something wrong here? It's know issue, see "[PATCH] oslib-posix: initialize mutex and condition variable for a fix >
