From: Chandra Seetharaman Date: Thu, 13 Jan 2011 20:00:01 +0000 (+0000) Subject: dm mpath: delay activate_path retry on SCSI_DH_RETRY X-Git-Tag: v2.6.38-rc1~221^2~3 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4e2d19e46b507018c6ed15f6c081d8f887ae229c;p=pandora-kernel.git dm mpath: delay activate_path retry on SCSI_DH_RETRY This patch adds a user-configurable 'pg_init_delay_msecs' feature. Use this feature to specify the number of milliseconds to delay before retrying scsi_dh_activate, when SCSI_DH_RETRY is returned. SCSI Device Handlers return SCSI_DH_IMM_RETRY if we could retry activation immediately and SCSI_DH_RETRY in cases where it is better to retry after some delay. Currently we immediately retry scsi_dh_activate irrespective of SCSI_DH_IMM_RETRY and SCSI_DH_RETRY. The 'pg_init_delay_msecs' feature may be provided during table create or load, e.g.: dmsetup create --table "0 20971520 multipath 3 queue_if_no_path \ pg_init_delay_msecs 2500 ..." mpatha The default for 'pg_init_delay_msecs' is 2000 milliseconds. Maximum configurable delay is 60000 milliseconds. Specifying a 'pg_init_delay_msecs' of 0 will cause immediate retry. Signed-off-by: Nikanth Karthikesan Signed-off-by: Chandra Seetharaman Acked-by: Mike Christie Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon --- Reading git-diff-tree failed