On 9/2/24 02:00, Damien Le Moal wrote:
The 512B buffer sector_buf field of struct ata_port is used for scanning devices as well as during error recovery with ata EH. This buffer is thus useless if a port does not have a device connected to it. And also given that commands using this buffer are issued to devices, and not to ports, move this buffer definition from struct ata_port to struct ata_device. This change slightly increases system memory usage for systems using a port-multiplier as in that case we do not need a per-device buffer for scanning devices (PMP does not allow parallel scanning) nor for EH (as when entering EH we are guaranteed that all commands to all devices connected to the PMP have completed or have been aborted). However, this change reduces memory usage on systems that have many ports with only few devices rives connected, which is a much more common use case than the PMP use case. Signed-off-by: Damien Le Moal <dlemoal@xxxxxxxxxx> --- drivers/ata/libata-core.c | 63 ++++++++++++++++---------------------- drivers/ata/libata-eh.c | 2 +- drivers/ata/libata-pmp.c | 3 +- drivers/ata/libata-sata.c | 2 +- drivers/ata/libata-zpodd.c | 2 +- include/linux/libata.h | 4 ++- 6 files changed, 33 insertions(+), 43 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, Frankenstr. 146, 90461 Nürnberg HRB 36809 (AG Nürnberg), GF: I. Totev, A. McDonald, W. Knoblich
