Re: [RFC][PATCH 0/3] VM throttling: avoid blocking occasional writers

2007-03-07 Thread Yuji Kakutani
Hi, Thank you for your comments. Leroy van Logchem wrote: >The default dirty_ratio on most 2.6 kernels tend to be too large imo. >If you are going to do sustained writes multiple times the size of >the memory you have at least two problems. > >1) The precious dentry and inodecache will be dropped

Re: [RFC][PATCH 0/3] VM throttling: avoid blocking occasional writers

2007-03-07 Thread Yuji Kakutani
Hi, Thank you for your comments. Leroy van Logchem wrote: The default dirty_ratio on most 2.6 kernels tend to be too large imo. If you are going to do sustained writes multiple times the size of the memory you have at least two problems. 1) The precious dentry and inodecache will be dropped

Re: [RFC][PATCH 0/3] VM throttling: avoid blocking occasional writers

2007-03-02 Thread Brice Figureau
Hi, On Fri, 2007-03-02 at 13:06 +, Leroy van Logchem wrote: > > I'm sorry to piggy-back this thread. > > > > Could it be what I'm experiencing in the following bugzilla report: > > http://bugzilla.kernel.org/show_bug.cgi?id=7372 > > > > As I explained in the report, I see this issue only

Re: [RFC][PATCH 0/3] VM throttling: avoid blocking occasional writers

2007-03-02 Thread Leroy van Logchem
> I'm sorry to piggy-back this thread. > > Could it be what I'm experiencing in the following bugzilla report: > http://bugzilla.kernel.org/show_bug.cgi?id=7372 > > As I explained in the report, I see this issue only since 2.6.18. > So if your concern is related to mine, what could have changed

Re: [RFC][PATCH 0/3] VM throttling: avoid blocking occasional writers

2007-03-02 Thread Brice Figureau
Hi, On Thu, 2007-03-01 at 12:47 +, Leroy van Logchem wrote: > Tomoki Sekiyama hitachi.com> writes: > > thanks for your comments. > > The default dirty_ratio on most 2.6 kernels tend to be too large imo. > If you are going to do sustained writes multiple times the size of > the memory you

Re: [RFC][PATCH 0/3] VM throttling: avoid blocking occasional writers

2007-03-02 Thread Brice Figureau
Hi, On Thu, 2007-03-01 at 12:47 +, Leroy van Logchem wrote: Tomoki Sekiyama tomoki.sekiyama.qu at hitachi.com writes: thanks for your comments. The default dirty_ratio on most 2.6 kernels tend to be too large imo. If you are going to do sustained writes multiple times the size of the

Re: [RFC][PATCH 0/3] VM throttling: avoid blocking occasional writers

2007-03-02 Thread Leroy van Logchem
I'm sorry to piggy-back this thread. Could it be what I'm experiencing in the following bugzilla report: http://bugzilla.kernel.org/show_bug.cgi?id=7372 As I explained in the report, I see this issue only since 2.6.18. So if your concern is related to mine, what could have changed between

Re: [RFC][PATCH 0/3] VM throttling: avoid blocking occasional writers

2007-03-02 Thread Brice Figureau
Hi, On Fri, 2007-03-02 at 13:06 +, Leroy van Logchem wrote: I'm sorry to piggy-back this thread. Could it be what I'm experiencing in the following bugzilla report: http://bugzilla.kernel.org/show_bug.cgi?id=7372 As I explained in the report, I see this issue only since 2.6.18.

Re: [RFC][PATCH 0/3] VM throttling: avoid blocking occasional writers

2007-03-01 Thread Tomoki Sekiyama
Hi Kamezawa-san, KAMEZAWA Hiroyuki wrote: >>> Interesting, but how about adjust this parameter like below instead of >>> adding new control knob ?(this kind of knob is not easy to use.) >>> count_dirty_pages_on_device_limited(bdi, writechunk) above returns >>> dirty pages on bdi. if # of

Re: [RFC][PATCH 0/3] VM throttling: avoid blocking occasional writers

2007-03-01 Thread Leroy van Logchem
Tomoki Sekiyama hitachi.com> writes: > thanks for your comments. The default dirty_ratio on most 2.6 kernels tend to be too large imo. If you are going to do sustained writes multiple times the size of the memory you have at least two problems. 1) The precious dentry and inodecache will be

Re: [RFC][PATCH 0/3] VM throttling: avoid blocking occasional writers

2007-03-01 Thread Leroy van Logchem
Tomoki Sekiyama tomoki.sekiyama.qu at hitachi.com writes: thanks for your comments. The default dirty_ratio on most 2.6 kernels tend to be too large imo. If you are going to do sustained writes multiple times the size of the memory you have at least two problems. 1) The precious dentry and

Re: [RFC][PATCH 0/3] VM throttling: avoid blocking occasional writers

2007-03-01 Thread Tomoki Sekiyama
Hi Kamezawa-san, KAMEZAWA Hiroyuki wrote: Interesting, but how about adjust this parameter like below instead of adding new control knob ?(this kind of knob is not easy to use.) snip count_dirty_pages_on_device_limited(bdi, writechunk) above returns dirty pages on bdi. if # of dirty_pages

Re: [RFC][PATCH 0/3] VM throttling: avoid blocking occasional writers

2007-02-26 Thread KAMEZAWA Hiroyuki
On Tue, 27 Feb 2007 09:50:16 +0900 Tomoki Sekiyama <[EMAIL PROTECTED]> wrote: > Hi Kamezawa-san, > > thanks for your reply. > > KAMEZAWA Hiroyuki wrote: > > Interesting, but how about adjust this parameter like below instead of > > adding new control knob ?(this kind of knob is not easy to

Re: [RFC][PATCH 0/3] VM throttling: avoid blocking occasional writers

2007-02-26 Thread Tomoki Sekiyama
Hi Nikita, thanks for your comments. Nikita Danilov wrote: >> While Dirty+Writeback pages get more than 40% of memory, process-B is >> blocked in balance_dirty_pages() until writeback of some (`write_chunk', >> typically = 1536) dirty pages on disk-b is started. > > May be the simpler solution

Re: [RFC][PATCH 0/3] VM throttling: avoid blocking occasional writers

2007-02-26 Thread Tomoki Sekiyama
Hi Kamezawa-san, thanks for your reply. KAMEZAWA Hiroyuki wrote: > Interesting, but how about adjust this parameter like below instead of > adding new control knob ?(this kind of knob is not easy to use.) > > == > struct writeback_control wbc = { > .bdi

Re: [RFC][PATCH 0/3] VM throttling: avoid blocking occasional writers

2007-02-26 Thread Tomoki Sekiyama
Hi Kamezawa-san, thanks for your reply. KAMEZAWA Hiroyuki wrote: Interesting, but how about adjust this parameter like below instead of adding new control knob ?(this kind of knob is not easy to use.) == struct writeback_control wbc = { .bdi

Re: [RFC][PATCH 0/3] VM throttling: avoid blocking occasional writers

2007-02-26 Thread Tomoki Sekiyama
Hi Nikita, thanks for your comments. Nikita Danilov wrote: While Dirty+Writeback pages get more than 40% of memory, process-B is blocked in balance_dirty_pages() until writeback of some (`write_chunk', typically = 1536) dirty pages on disk-b is started. May be the simpler solution is to use

Re: [RFC][PATCH 0/3] VM throttling: avoid blocking occasional writers

2007-02-26 Thread KAMEZAWA Hiroyuki
On Tue, 27 Feb 2007 09:50:16 +0900 Tomoki Sekiyama [EMAIL PROTECTED] wrote: Hi Kamezawa-san, thanks for your reply. KAMEZAWA Hiroyuki wrote: Interesting, but how about adjust this parameter like below instead of adding new control knob ?(this kind of knob is not easy to use.) ==

Re: [RFC][PATCH 0/3] VM throttling: avoid blocking occasional writers

2007-02-24 Thread Nikita Danilov
Tomoki Sekiyama writes: > Hi, Hello, > [...] > > While Dirty+Writeback pages get more than 40% of memory, process-B is > blocked in balance_dirty_pages() until writeback of some (`write_chunk', > typically = 1536) dirty pages on disk-b is started. May be the simpler solution is to use

Re: [RFC][PATCH 0/3] VM throttling: avoid blocking occasional writers

2007-02-24 Thread Nikita Danilov
Tomoki Sekiyama writes: Hi, Hello, [...] While Dirty+Writeback pages get more than 40% of memory, process-B is blocked in balance_dirty_pages() until writeback of some (`write_chunk', typically = 1536) dirty pages on disk-b is started. May be the simpler solution is to use

Re: [RFC][PATCH 0/3] VM throttling: avoid blocking occasional writers

2007-02-23 Thread KAMEZAWA Hiroyuki
On Fri, 23 Feb 2007 21:03:37 +0900 Tomoki Sekiyama <[EMAIL PROTECTED]> wrote: > Hi, > > I have observed a problem that write(2) can be blocked for a long time > if a system has several disks and is under heavy I/O pressure. This > patchset is to avoid the problem. > > Example of the probrem: >

[RFC][PATCH 0/3] VM throttling: avoid blocking occasional writers

2007-02-23 Thread Tomoki Sekiyama
Hi, I have observed a problem that write(2) can be blocked for a long time if a system has several disks and is under heavy I/O pressure. This patchset is to avoid the problem. Example of the probrem: There are two processes on a system which has two disks. Process-A writes heavily to disk-a,

[RFC][PATCH 0/3] VM throttling: avoid blocking occasional writers

2007-02-23 Thread Tomoki Sekiyama
Hi, I have observed a problem that write(2) can be blocked for a long time if a system has several disks and is under heavy I/O pressure. This patchset is to avoid the problem. Example of the probrem: There are two processes on a system which has two disks. Process-A writes heavily to disk-a,

Re: [RFC][PATCH 0/3] VM throttling: avoid blocking occasional writers

2007-02-23 Thread KAMEZAWA Hiroyuki
On Fri, 23 Feb 2007 21:03:37 +0900 Tomoki Sekiyama [EMAIL PROTECTED] wrote: Hi, I have observed a problem that write(2) can be blocked for a long time if a system has several disks and is under heavy I/O pressure. This patchset is to avoid the problem. Example of the probrem: There