adding entries to swapper_pg_dir after boot
Hi, I am trying to address a range of special addresses in the kernel that are not visible(addressable) to memory at boot time. I create a whole in the virtual address space and then I want to try to add page table entries to the kernel page table for these VA-MY(PA) translation. (Let me know if there is a better way to do this) I was wondering if anyone knew how do I go about this. I can access the kernel page tables from swapper_pg_dir. How do I add pgd enteries for these virtual addresses? Any sample code/reference will be helpful. Thanks, Asim ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: invoking zcache w/o using a workload
Thanks Mulyadi - I was able to trigger clean cache by reducing the memory and using dd to create a file larger than RAM. -Asim On Mon, Aug 13, 2012 at 10:42 PM, Mulyadi Santosa mulyadi.sant...@gmail.com wrote: On Tue, Aug 14, 2012 at 1:53 AM, Asim linka...@gmail.com wrote: Thanks Mulyadi for your response. zcache has cleancache (a third level page cache) and front swap(swap cache). I am trying to trigger clean cache and now the swap device. But my guess is reducing the memory should also cause these evictions rapidly. Awaiting news from you about this experiment :) -- regards, Mulyadi Santosa Freelance Linux trainer and consultant blog: the-hydra.blogspot.com training: mulyaditraining.blogspot.com ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: invoking zcache w/o using a workload
Thanks Mulyadi for your response. zcache has cleancache (a third level page cache) and front swap(swap cache). I am trying to trigger clean cache and now the swap device. But my guess is reducing the memory should also cause these evictions rapidly. Thanks, Asim On Sun, Aug 12, 2012 at 11:56 PM, Mulyadi Santosa mulyadi.sant...@gmail.com wrote: Hi... On Mon, Aug 13, 2012 at 3:58 AM, Asim linka...@gmail.com wrote: Is there a way I can trigger zcache_get/put (specifically clean cache) with a simple unit test (as opposed to running a workload) ? This will greatly reduce my test/build time. I am a new user of zcache (due to playing with recent Mint release). I got impression that by reducing mapped memory you have (using mem= kernel parameter) and putting zram/zcache into high priority swap, is enough to quickly trigger allocation into zcache. of course, you need memory hogger for that, something like tail -f /dev/zero. CMIIW if misunderstood you... -- regards, Mulyadi Santosa Freelance Linux trainer and consultant blog: the-hydra.blogspot.com training: mulyaditraining.blogspot.com ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
invoking zcache w/o using a workload
Hi, I was playing around with zcache and fiddling with different compression algorithms. Furthermore, I was integrating some checksum algorithms for cleancache for my own project goals. Unfortunately, I need to run a workload to trigger zcache. Is there a way I can trigger zcache_get/put (specifically clean cache) with a simple unit test (as opposed to running a workload) ? This will greatly reduce my test/build time. I was wondering if there is an existing unit test-suite. Or I could write a simple kernel module to trigger put/get but I was wondering how to go about invoking these operations. My guess is calling cleancache_get/free using a page off (get_free_page) will not invoke zcache. Any suggestions will be useful. Thanks, Asim ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: zcache and zsmalloc
Yeah - I see lots of BUG_ON(!irqs_disabled()) in zcache code while placing and compressing the page(and also other places). I am not clear what you mean when you say zcache does so for other reasons. My guess was when clean zcache_put_page is called it holds locks (mapping-tree_lock) that conflicts xsmalloc pool allocations. If zsmalloc has no such issues, can these be removed? Thanks, Asim - Adding the correct kernel newbies address with entire conversation intact for reference. On Wed, Jun 27, 2012 at 1:26 PM, Seth Jennings sjenn...@linux.vnet.ibm.com wrote: On 06/27/2012 01:04 PM, Asim wrote: This query relates zcache and the new zsmalloc patches. I was looking through zcache code and your various zsmalloc patches. I am aware the zcache disables interrupts due to xvmalloc pool allocations.However, does the zsmalloc code also needs to disable interrupts while placing a page in zcache? (Adding Nitin to Cc) None of the functions need interrupts/preemption to be disabled before calling them, even though zcache does for other reasons. zs_map_object() will return with page faults and preemption disabled by kmap_atomic() and get_cpu_var() respectively. This is to insure atomic access to the mapping_area structure. They are re-enabled in zs_unmap_object(). -- Seth ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: pci config space
Thanks for your response. On Sat, Feb 19, 2011 at 11:33 PM, Greg KH g...@kroah.com wrote: On Sat, Feb 19, 2011 at 03:32:51PM -0600, Asim wrote: Hi, While this may just be connecting the dots, I am not able to fully understand how pci_save_state works. I see that the pci_save_state and pci_restore_state are invoked at suspend and resume. This saves the PCI configuration registers during suspend. Are these the device registers or bridge registers? It depends if the device is a device or a bridge :) Consequently, is the pci_save_state and driver suspend routine saving the full device state/device state exposed to PCI or PCI state ? Yes. Hope this helps, greg k-h ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
