On 4/8/21 3:45 AM, Douglas Gilbert wrote:
Since the version 2 driver, the state of the driver can be found with 'cat /proc/scsi/sg/debug'. As the driver becomes more threaded and IO faster (e.g. scsi_debug with a command timer of 5 microseconds), the existing state dump can become misleading as the state can change during the "snapshot". The new approach in this patch is to allocate a buffer of SG_PROC_DEBUG_SZ bytes and use scnprintf() to populate it. Only when the whole state is captured (or the buffer fills) is the output to the caller's terminal performed. The previous approach was line based: assemble a line of information and then output it. Locks are taken as required for short periods and should not interfere with a disk IO intensive program. Operations such as closing a sg file descriptor or removing a sg device may be held up for a short while (microseconds). Signed-off-by: Douglas Gilbert <dgilbert@xxxxxxxxxxxx> --- drivers/scsi/sg.c | 256 ++++++++++++++++++++++++++++++++-------------- 1 file changed, 177 insertions(+), 79 deletions(-) Reviewed-by: Hannes Reinecke <hare@xxxxxxx>
Cheers, Hannes -- Dr. Hannes Reinecke Kernel Storage Architect hare@xxxxxxx +49 911 74053 688 SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg HRB 36809 (AG Nürnberg), Geschäftsführer: Felix Imendörffer
