Re: [RFC PATCH v1 0/3] kdump, vmcore: Map vmcore memory in direct mapping region

2013-01-20 Thread HATAYAMA Daisuke
From: Vivek Goyal Subject: Re: [RFC PATCH v1 0/3] kdump, vmcore: Map vmcore memory in direct mapping region Date: Fri, 18 Jan 2013 15:54:13 -0500 > On Fri, Jan 18, 2013 at 11:06:59PM +0900, HATAYAMA Daisuke wrote: > > [..] >> > These are impressive improvements. I missed the

Re: [RFC PATCH v1 0/3] kdump, vmcore: Map vmcore memory in direct mapping region

2013-01-18 Thread Vivek Goyal
On Fri, Jan 18, 2013 at 11:06:59PM +0900, HATAYAMA Daisuke wrote: [..] > > These are impressive improvements. I missed the discussion on mmap(). > > So why couldn't we provide mmap() interface for /proc/vmcore. If that > > works then application can select to mmap/unmap bigger chunks of file > > (

Re: [RFC PATCH v1 0/3] kdump, vmcore: Map vmcore memory in direct mapping region

2013-01-18 Thread HATAYAMA Daisuke
From: Vivek Goyal Subject: Re: [RFC PATCH v1 0/3] kdump, vmcore: Map vmcore memory in direct mapping region Date: Thu, 17 Jan 2013 17:13:48 -0500 > On Thu, Jan 10, 2013 at 08:59:34PM +0900, HATAYAMA Daisuke wrote: >> Currently, kdump reads the 1st kernel's memory, called old me

Re: [RFC PATCH v1 0/3] kdump, vmcore: Map vmcore memory in direct mapping region

2013-01-17 Thread Vivek Goyal
On Thu, Jan 10, 2013 at 08:59:34PM +0900, HATAYAMA Daisuke wrote: > Currently, kdump reads the 1st kernel's memory, called old memory in > the source code, using ioremap per a single page. This causes big > performance degradation since page tables modification and tlb flush > happen each time the