Re: Process Scheduling Issue using sg/libata

2007-11-18 Thread Fajun Chen
On 11/18/07, Mark Lord [EMAIL PROTECTED] wrote: Fajun Chen wrote: On 11/17/07, Mark Lord [EMAIL PROTECTED] wrote: .. What you probably intended to do instead, was to use mmap to just allocate some page-aligned RAM, not to actually mmap'd any on-disk data. Right? Here's how that's

Re: Process Scheduling Issue using sg/libata

2007-11-18 Thread Mark Lord
Fajun Chen wrote: .. I verified your program works in my system and my application works as well if changed accordingly. However, this change (indirect IO in sg term) may come at a performance cost for IO intensive applications since it does NOT utilize mmaped buffer managed by sg driver.

Re: Process Scheduling Issue using sg/libata

2007-11-18 Thread Fajun Chen
On 11/18/07, Mark Lord [EMAIL PROTECTED] wrote: Fajun Chen wrote: .. I verified your program works in my system and my application works as well if changed accordingly. However, this change (indirect IO in sg term) may come at a performance cost for IO intensive applications since it

Re: Process Scheduling Issue using sg/libata

2007-11-18 Thread Mark Lord
Fajun Chen wrote: As a matter of fact, I'm using /dev/sg*. Due to the size of my test application, I have not be able to compress it into a small and publishable form. However, this issue can be easily reproduced on my ARM XScale target using sg3_util code as follows: 1. Run printtime.c

Re: slow after upgrade to CentOS 5 (RHEL5)

2007-11-18 Thread Anthony Ewell
James Bottomley wrote: Please don't drop the cc lists. There are others who probably have more informed opinions than I do who won't get to comment if they don't see it. On Sun, 2007-10-28 at 17:36 -0700, Anthony Ewell wrote: James Bottomley wrote: On Sat, 2007-10-27 at 13:21 -0700, Anthony

[PATCH]scsi: BUG_ON() impossible condition.

2007-11-18 Thread Rusty Russell
If blk_rq_map_sg wrote more than was allocated in the scatterlist, BUG_ON() is probably the right thing to do. Signed-off-by: Rusty Russell [EMAIL PROTECTED] Acked-by: Jens Axboe [EMAIL PROTECTED] --- drivers/scsi/scsi_tgt_lib.c | 11 +++ 1 files changed, 3 insertions(+), 8

SCSI breakage on non-cache coherent architectures

2007-11-18 Thread Benjamin Herrenschmidt
Hi James ! (Please CC me on replies as I'm not subscribed to linux-scsi) I've been debugging various issues on the PowerPC 44x embedded architecture which happens to have non-coherent PCI DMA. One of the problem I'm hitting is that one really need to enforce kmalloc alignement to cache lines or

Re: [PATCH] debloat aic7xxx and aic79xx drivers

2007-11-18 Thread Hannes Reinecke
Denys Vlasenko wrote: Hi Matthew, Hannes, Any news on this? Where these patches stand now? Are they accepted into linux-scsi? On Wednesday 14 November 2007 13:39, Denys Vlasenko wrote: hi Matthew, On Wednesday 14 November 2007 06:35, Hannes Reinecke wrote: Matthew Wilcox wrote: On