* Bug 220102 - struct taskstats breaks backward compatibility since version 15 @ 2025-05-09 18:35 Boian Bonev 2025-05-09 21:17 ` Andrew Morton 0 siblings, 1 reply; 6+ messages in thread From: Boian Bonev @ 2025-05-09 18:35 UTC (permalink / raw) To: linux-kernel Cc: Balbir Singh, Yang Yang, Wang Yaxin, Kun Jiang, xu xin, Andrew Morton Hello! 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. I think that change has to be reverted and the added fields moved to the end of the structure. Also bumping the version to 16 after the change is a good idea in order for the userspace software to be able to distinguish the different formats. https://bugzilla.kernel.org/show_bug.cgi?id=220102 With best regards, b. ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Bug 220102 - struct taskstats breaks backward compatibility since version 15 2025-05-09 18:35 Bug 220102 - struct taskstats breaks backward compatibility since version 15 Boian Bonev @ 2025-05-09 21:17 ` Andrew Morton 2025-05-10 11:45 ` Boian Bonev 0 siblings, 1 reply; 6+ messages in thread From: Andrew Morton @ 2025-05-09 21:17 UTC (permalink / raw) To: Boian Bonev Cc: linux-kernel, Balbir Singh, Yang Yang, Wang Yaxin, Kun Jiang, xu xin On Fri, 09 May 2025 21:35:59 +0300 Boian Bonev <bbonev@devuan.org> wrote: > Hello! > > 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. Yikes. Yes, we did change the versioning but such an incompatibility seems undesirable and unnecessarily disruptive. > I think that change has to be reverted and the added fields moved to > the end of the structure. Also bumping the version to 16 after the > change is a good idea in order for the userspace software to be able to > distinguish the different formats. Yes, please send along the patch. Include the suitable Fixes: and we can backport this into the affected -stable kernels. > https://bugzilla.kernel.org/show_bug.cgi?id=220102 ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Bug 220102 - struct taskstats breaks backward compatibility since version 15 2025-05-09 21:17 ` Andrew Morton @ 2025-05-10 11:45 ` Boian Bonev 2025-05-10 20:23 ` Andrew Morton 0 siblings, 1 reply; 6+ messages in thread From: Boian Bonev @ 2025-05-10 11:45 UTC (permalink / raw) To: Andrew Morton Cc: linux-kernel, Balbir Singh, Yang Yang, Wang Yaxin, Kun Jiang, xu xin On Fri, 2025-05-09 at 14:17 -0700, Andrew Morton wrote: > Yes, please send along the patch. Include the suitable Fixes: and we > can backport this into the affected -stable kernels. > > > https://bugzilla.kernel.org/show_bug.cgi?id=220102 My patch was attached in the bugzilla above. I also see that Wang Yaxin <wang.yaxin@zte.com.cn> has already sent a different but working patch... With best regards, b. ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Bug 220102 - struct taskstats breaks backward compatibility since version 15 2025-05-10 11:45 ` Boian Bonev @ 2025-05-10 20:23 ` Andrew Morton 2025-05-10 22:03 ` Boian Bonev 0 siblings, 1 reply; 6+ messages in thread From: Andrew Morton @ 2025-05-10 20:23 UTC (permalink / raw) To: Boian Bonev Cc: linux-kernel, Balbir Singh, Yang Yang, Wang Yaxin, Kun Jiang, xu xin On Sat, 10 May 2025 14:45:31 +0300 Boian Bonev <bbonev@devuan.org> wrote: > On Fri, 2025-05-09 at 14:17 -0700, Andrew Morton wrote: > > Yes, please send along the patch. Include the suitable Fixes: and we > > can backport this into the affected -stable kernels. > > > > > https://bugzilla.kernel.org/show_bug.cgi?id=220102 > > My patch was attached in the bugzilla above. We barely use bugzilla at all for kernel development. I think I wish that kernel bugzilla was simply shut down, replaced with a page to help people to email their bug reports. > I also see that Wang Yaxin > <wang.yaxin@zte.com.cn> has already sent a different but working > patch... Cool. Except I cannot find that patch. Help? ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Bug 220102 - struct taskstats breaks backward compatibility since version 15 2025-05-10 20:23 ` Andrew Morton @ 2025-05-10 22:03 ` Boian Bonev 2025-05-13 0:58 ` Andrew Morton 0 siblings, 1 reply; 6+ messages in thread From: Boian Bonev @ 2025-05-10 22:03 UTC (permalink / raw) To: Andrew Morton Cc: linux-kernel, Balbir Singh, Yang Yang, Wang Yaxin, Kun Jiang, xu xin [-- Attachment #1: Type: text/plain, Size: 621 bytes --] On Sat, 2025-05-10 at 13:23 -0700, Andrew Morton wrote: > > > > https://bugzilla.kernel.org/show_bug.cgi?id=220102 > > > > My patch was attached in the bugzilla above. > > We barely use bugzilla at all for kernel development. I think I wish > that kernel bugzilla was simply shut down, replaced with a page to > help people to email their bug reports. I am not sure if my patch is up to standards, PFA > > > I also see that Wang Yaxin > > <wang.yaxin@zte.com.cn> has already sent a different but working > > patch... > > Cool. Except I cannot find that patch. Help? That one was on email. [-- Attachment #2: taskstats_compat.patch --] [-- Type: text/x-patch, Size: 3161 bytes --] diff --git a/include/uapi/linux/taskstats.h b/include/uapi/linux/taskstats.h index 95762232e018..7f169c65b16e 100644 --- a/include/uapi/linux/taskstats.h +++ b/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 @@ -161,8 +155,8 @@ struct taskstats { __u64 write_bytes; /* bytes of write I/O */ __u64 cancelled_write_bytes; /* bytes of cancelled write I/O */ - __u64 nvcsw; /* voluntary_ctxt_switches */ - __u64 nivcsw; /* nonvoluntary_ctxt_switches */ + __u64 nvcsw; /* voluntary_ctxt_switches */ + __u64 nivcsw; /* nonvoluntary_ctxt_switches */ /* time accounting for SMT machines */ __u64 ac_utimescaled; /* utime scaled on frequency etc */ @@ -172,14 +166,10 @@ 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 +177,6 @@ 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 */ @@ -208,17 +196,30 @@ struct taskstats { /* v12 end */ /* v13: Delay waiting for write-protect copy */ - __u64 wpcopy_count; - __u64 wpcopy_delay_total; - __u64 wpcopy_delay_max; - __u64 wpcopy_delay_min; + __u64 wpcopy_count; + __u64 wpcopy_delay_total; /* v14: Delay waiting for IRQ/SOFTIRQ */ - __u64 irq_count; - __u64 irq_delay_total; - __u64 irq_delay_max; - __u64 irq_delay_min; - /* v15: add Delay max */ + __u64 irq_count; + __u64 irq_delay_total; + /* v15: broken compatibility */ + /* v16: add Delay min/max */ + __u64 cpu_delay_min; + __u64 cpu_delay_max; + __u64 blkio_delay_min; + __u64 blkio_delay_max; + __u64 swapin_delay_min; + __u64 swapin_delay_max; + __u64 freepages_delay_min; + __u64 freepages_delay_max; + __u64 thrashing_delay_min; + __u64 thrashing_delay_max; + __u64 compact_delay_min; + __u64 compact_delay_max; + __u64 wpcopy_delay_min; + __u64 wpcopy_delay_max; + __u64 irq_delay_min; + __u64 irq_delay_max; }; ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Bug 220102 - struct taskstats breaks backward compatibility since version 15 2025-05-10 22:03 ` Boian Bonev @ 2025-05-13 0:58 ` Andrew Morton 0 siblings, 0 replies; 6+ messages in thread From: Andrew Morton @ 2025-05-13 0:58 UTC (permalink / raw) To: Boian Bonev Cc: linux-kernel, Balbir Singh, Yang Yang, Wang Yaxin, Kun Jiang, xu xin On Sun, 11 May 2025 01:03:58 +0300 Boian Bonev <bbonev@devuan.org> wrote: > > > > > I also see that Wang Yaxin > > > <wang.yaxin@zte.com.cn> has already sent a different but working > > > patch... > > > > Cool. Except I cannot find that patch. Help? > > That one was on email. > > > diff --git a/include/uapi/linux/taskstats.h b/include/uapi/linux/taskstats.h > index 95762232e018..7f169c65b16e 100644 I don't think I've yet seen a usable patch for this issue? Can someone please email one at me in the usual fashion? ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2025-05-13 0:58 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2025-05-09 18:35 Bug 220102 - struct taskstats breaks backward compatibility since version 15 Boian Bonev 2025-05-09 21:17 ` Andrew Morton 2025-05-10 11:45 ` Boian Bonev 2025-05-10 20:23 ` Andrew Morton 2025-05-10 22:03 ` Boian Bonev 2025-05-13 0:58 ` Andrew Morton
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