The patch titled Subject: taskstats: fix struct taskstats breaks backward compatibility since version 15 has been added to the -mm mm-hotfixes-unstable branch. Its filename is taskstats-fix-struct-taskstats-breaks-backward-compatibility-since-version-15.patch
This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches...
This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------ From: Wang Yaxin wang.yaxin@zte.com.cn Subject: taskstats: fix struct taskstats breaks backward compatibility since version 15 Date: Sat, 10 May 2025 15:54:13 +0800 (CST)
Problem ======== commit 658eb5ab916d ("delayacct: add delay max to record delay peak") - adding more fields commit f65c64f311ee ("delayacct: add delay min to record delay peak") - adding more fields commit b016d0873777 ("taskstats: modify taskstats version") - version bump to 15
Since version 15 (TASKSTATS_VERSION=15) the new layout of the structure adds fields in the middle of the structure, rendering all old software incompatible with newer kernels and software compiled against the new kernel headers incompatible with older kernels.
Solution ========= move delay max and delay min to the end of taskstat, and bump the version to 16 after the change
Link: https://lkml.kernel.org/r/20250510155413259V4JNRXxukdDgzsaL0Fo6a@zte.com.cn Fixes: f65c64f311ee ("delayacct: add delay min to record delay peak") Signed-off-by: Wang Yaxin wang.yaxin@zte.com.cn Signed-off-by: xu xin xu.xin16@zte.com.cn Signed-off-by: Kun Jiang jiang.kun2@zte.com.cn Cc: Balbir Singh bsingharora@gmail.com Cc: Yang Yang yang.yang29@zte.com.cn Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---
include/uapi/linux/taskstats.h | 43 +++++++++++++++++++------------ 1 file changed, 27 insertions(+), 16 deletions(-)
--- a/include/uapi/linux/taskstats.h~taskstats-fix-struct-taskstats-breaks-backward-compatibility-since-version-15 +++ a/include/uapi/linux/taskstats.h @@ -34,7 +34,7 @@ */
-#define TASKSTATS_VERSION 15 +#define TASKSTATS_VERSION 16 #define TS_COMM_LEN 32 /* should be >= TASK_COMM_LEN * in linux/sched.h */
@@ -72,8 +72,6 @@ struct taskstats { */ __u64 cpu_count __attribute__((aligned(8))); __u64 cpu_delay_total; - __u64 cpu_delay_max; - __u64 cpu_delay_min;
/* Following four fields atomically updated using task->delays->lock */
@@ -82,14 +80,10 @@ struct taskstats { */ __u64 blkio_count; __u64 blkio_delay_total; - __u64 blkio_delay_max; - __u64 blkio_delay_min;
/* Delay waiting for page fault I/O (swap in only) */ __u64 swapin_count; __u64 swapin_delay_total; - __u64 swapin_delay_max; - __u64 swapin_delay_min;
/* cpu "wall-clock" running time * On some architectures, value will adjust for cpu time stolen @@ -172,14 +166,11 @@ struct taskstats { /* Delay waiting for memory reclaim */ __u64 freepages_count; __u64 freepages_delay_total; - __u64 freepages_delay_max; - __u64 freepages_delay_min; +
/* Delay waiting for thrashing page */ __u64 thrashing_count; __u64 thrashing_delay_total; - __u64 thrashing_delay_max; - __u64 thrashing_delay_min;
/* v10: 64-bit btime to avoid overflow */ __u64 ac_btime64; /* 64-bit begin time */ @@ -187,8 +178,6 @@ struct taskstats { /* v11: Delay waiting for memory compact */ __u64 compact_count; __u64 compact_delay_total; - __u64 compact_delay_max; - __u64 compact_delay_min;
/* v12 begin */ __u32 ac_tgid; /* thread group ID */ @@ -210,15 +199,37 @@ struct taskstats { /* v13: Delay waiting for write-protect copy */ __u64 wpcopy_count; __u64 wpcopy_delay_total; - __u64 wpcopy_delay_max; - __u64 wpcopy_delay_min;
/* v14: Delay waiting for IRQ/SOFTIRQ */ __u64 irq_count; __u64 irq_delay_total; + + /* v15: add Delay max and Delay min */ + + /* v16: move Delay max and Delay min to the end of taskstat */ + __u64 cpu_delay_max; + __u64 cpu_delay_min; + + __u64 blkio_delay_max; + __u64 blkio_delay_min; + + __u64 swapin_delay_max; + __u64 swapin_delay_min; + + __u64 freepages_delay_max; + __u64 freepages_delay_min; + + __u64 thrashing_delay_max; + __u64 thrashing_delay_min; + + __u64 compact_delay_max; + __u64 compact_delay_min; + + __u64 wpcopy_delay_max; + __u64 wpcopy_delay_min; + __u64 irq_delay_max; __u64 irq_delay_min; - /* v15: add Delay max */ };
_
Patches currently in -mm which might be from wang.yaxin@zte.com.cn are
taskstats-fix-struct-taskstats-breaks-backward-compatibility-since-version-15.patch