Re: kdump detection in SCSI drivers
Hi! How do we know when little memory is available? Kernel already scales its hash tables according to total RAM available, perhaps you can use similar mechanism? Other suggestion which came about was to parse the kernel command line and look for elfcorehdr=. Is this ok? Is kernel command line visible to the SCSI drivers? Kernel command line probably is visible, but I'd recommend against doing that. Pavel Cc: Linux-scsi@vger.kernel.org; [EMAIL PROTECTED] Subject: Re: kdump detection in SCSI drivers Hi, Is there a standard way for drivers (RAID) to detect if the current kernel is running in kdump mode? We would like to adjust driver behavior dynamically when kdump is active by scaling down resources. Perhaps you should be automatically using little resources when little memory is available, or something? With upcomping kjump patches, it is more interesting than kdump vs. no kdump. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html - To unsubscribe from this list: send the line unsubscribe linux-scsi in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: kdump detection in SCSI drivers
Pavel Machek sez: Other suggestion which came about was to parse the kernel command line and look for elfcorehdr=. Is this ok? Is kernel command line visible to the SCSI drivers? Kernel command line probably is visible, but I'd recommend against doing that. Probably just as pregnant of a plan, what about looking for the reset_devices being none-zero? It was introduced for kdump to address the problem with devices that maintain state outside of the driver and the intent is to have it always set in the kdump kernel context. Personally, I'd code the driver to acquire memory normally, and have a backup plan to acquire less should the allocation fail in a memory limited environment ;-/ Sincerely -- Mark Salyzyn - To unsubscribe from this list: send the line unsubscribe linux-scsi in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: kdump detection in SCSI drivers
Hi, Is there a standard way for drivers (RAID) to detect if the current kernel is running in kdump mode? We would like to adjust driver behavior dynamically when kdump is active by scaling down resources. Perhaps you should be automatically using little resources when little memory is available, or something? With upcomping kjump patches, it is more interesting than kdump vs. no kdump. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html - To unsubscribe from this list: send the line unsubscribe linux-scsi in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: kdump detection in SCSI drivers
How do we know when little memory is available? Other suggestion which came about was to parse the kernel command line and look for elfcorehdr=. Is this ok? Is kernel command line visible to the SCSI drivers? Thanks -Atul -Original Message- From: Pavel Machek [mailto:[EMAIL PROTECTED] Sent: Thursday, September 20, 2007 6:43 AM To: Mukker, Atul Cc: Linux-scsi@vger.kernel.org; [EMAIL PROTECTED] Subject: Re: kdump detection in SCSI drivers Hi, Is there a standard way for drivers (RAID) to detect if the current kernel is running in kdump mode? We would like to adjust driver behavior dynamically when kdump is active by scaling down resources. Perhaps you should be automatically using little resources when little memory is available, or something? With upcomping kjump patches, it is more interesting than kdump vs. no kdump. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html - To unsubscribe from this list: send the line unsubscribe linux-scsi in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
