Re: 3.6-rc7 32-bit PAE miscalculates dirty page limits

2012-10-01 Thread H. Peter Anvin
On 10/01/2012 02:59 PM, Borislav Petkov wrote: > On Mon, Oct 01, 2012 at 02:53:40PM -0700, H. Peter Anvin wrote: >> It is very sad, though, that there are still drivers which don't work >> correctly in compat mode. Please report bugs on those -- that is just >> not acceptable. >> >> Unfortunately f

Re: 3.6-rc7 32-bit PAE miscalculates dirty page limits

2012-10-01 Thread Borislav Petkov
On Mon, Oct 01, 2012 at 02:53:40PM -0700, H. Peter Anvin wrote: > It is very sad, though, that there are still drivers which don't work > correctly in compat mode. Please report bugs on those -- that is just > not acceptable. > > Unfortunately few distros provide 64-bit kernels for their 32-bit > d

Re: 3.6-rc7 32-bit PAE miscalculates dirty page limits

2012-10-01 Thread H. Peter Anvin
On 10/01/2012 02:52 PM, Borislav Petkov wrote: > On Mon, Oct 01, 2012 at 11:10:47PM +0200, Pierre Beck wrote: >> But what about other folks who upgrade their PC? They won't know what >> hit them when their new PC crawls because disk is trashed. > > I don't know, maybe backup their data, install a

Re: 3.6-rc7 32-bit PAE miscalculates dirty page limits

2012-10-01 Thread Borislav Petkov
On Mon, Oct 01, 2012 at 11:10:47PM +0200, Pierre Beck wrote: > But what about other folks who upgrade their PC? They won't know what > hit them when their new PC crawls because disk is trashed. I don't know, maybe backup their data, install a nice 64-bit Linux distro of their liking along with a 6

Re: 3.6-rc7 32-bit PAE miscalculates dirty page limits

2012-10-01 Thread Pierre Beck
Hi, when I installed the original setup, there were no 64-bit PC CPUs. It's been kept up-to-date, changed hardware whenever necessary. But a shift from 32-bit to 64-bit isn't as simple as it seems. I tried 64-bit kernel with 32-bit userspace. It failed. The installed DVB-S tuner driver messe

Re: 3.6-rc7 32-bit PAE miscalculates dirty page limits

2012-09-30 Thread H. Peter Anvin
On 09/30/2012 02:38 AM, Pierre Beck wrote: Hi, there seems to be a bug in either ext4 or VM code triggered with 16 GB memory when compiled with 32-bit and PAE. dirty_background_ratio defaults to 10, dirty_ratio to 20. But in effect, dirty pages are strongly limited (zero or negative?). I observe

3.6-rc7 32-bit PAE miscalculates dirty page limits

2012-09-30 Thread Pierre Beck
Hi, there seems to be a bug in either ext4 or VM code triggered with 16 GB memory when compiled with 32-bit and PAE. dirty_background_ratio defaults to 10, dirty_ratio to 20. But in effect, dirty pages are strongly limited (zero or negative?). I observed extreme I/O wait states and slow disk