From: Christophe JAILLET Date: Sat, 2 Aug 2025 07:25:59 +0000 (+0200) Subject: block, bfq: Reorder struct bfq_iocq_bfqq_data X-Git-Tag: v6.17-rc1~9^2~3 X-Git-Url: http://git.ipfire.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=407728da41cd6450cec6a4277027015a75744d56;p=thirdparty%2Fkernel%2Fstable.git block, bfq: Reorder struct bfq_iocq_bfqq_data The size of struct bfq_iocq_bfqq_data can be reduced by moving a few fields around. On a x86_64, with allmodconfig, this shrinks the size from 144 to 128 bytes. The main benefit is to reduce the size of struct bfq_io_cq from 1360 to 1232. This structure is stored in a dedicated slab cache. So reducing its size improves cache usage. Signed-off-by: Christophe JAILLET Reviewed-by: Yu Kuai Link: https://lore.kernel.org/r/79394db1befaa658e8066b8e3348073ce27d9d26.1754119538.git.christophe.jaillet@wanadoo.fr Signed-off-by: Jens Axboe --- diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h index 687a3a7ba784..0b4704932d72 100644 --- a/block/bfq-iosched.h +++ b/block/bfq-iosched.h @@ -427,9 +427,6 @@ struct bfq_iocq_bfqq_data { */ bool saved_IO_bound; - u64 saved_io_start_time; - u64 saved_tot_idle_time; - /* * Same purpose as the previous fields for the values of the * field keeping the queue's belonging to a large burst @@ -450,6 +447,9 @@ struct bfq_iocq_bfqq_data { */ unsigned int saved_weight; + u64 saved_io_start_time; + u64 saved_tot_idle_time; + /* * Similar to previous fields: save wr information. */ @@ -457,13 +457,13 @@ struct bfq_iocq_bfqq_data { unsigned long saved_last_wr_start_finish; unsigned long saved_service_from_wr; unsigned long saved_wr_start_at_switch_to_srt; - unsigned int saved_wr_cur_max_time; struct bfq_ttime saved_ttime; + unsigned int saved_wr_cur_max_time; /* Save also injection state */ - u64 saved_last_serv_time_ns; unsigned int saved_inject_limit; unsigned long saved_decrease_time_jif; + u64 saved_last_serv_time_ns; /* candidate queue for a stable merge (due to close creation time) */ struct bfq_queue *stable_merge_bfqq;