Re: [PATCH v3 6/9] trace_uprobe: Support SDT markers having reference count (semaphore)

Thanks Oleg for the review, On 05/24/2018 09:56 PM, Oleg Nesterov wrote: > On 04/17, Ravi Bangoria wrote: >> >> @@ -941,6 +1091,9 @@ typedef bool (*filter_func_t)(struct uprobe_consumer >> *self, >> if (ret) >> goto err_buffer; >> >> +if (tu->ref_ctr_offset) >> +

Re: [PATCH v3 6/9] trace_uprobe: Support SDT markers having reference count (semaphore)

Thanks Oleg for the review, On 05/24/2018 09:56 PM, Oleg Nesterov wrote: > On 04/17, Ravi Bangoria wrote: >> >> @@ -941,6 +1091,9 @@ typedef bool (*filter_func_t)(struct uprobe_consumer >> *self, >> if (ret) >> goto err_buffer; >> >> +if (tu->ref_ctr_offset) >> +

Re: [PATCH v3 6/9] trace_uprobe: Support SDT markers having reference count (semaphore)

Hi Ravi, sorry for delay! I am trying to recall what this code should do ;) At first glance, I do not see any serious problem in this version... except it doesn't apply to Linus's tree. just one question for now. On 04/17, Ravi Bangoria wrote: > > @@ -941,6 +1091,9 @@ typedef bool

Re: [PATCH v3 6/9] trace_uprobe: Support SDT markers having reference count (semaphore)

Hi Ravi, sorry for delay! I am trying to recall what this code should do ;) At first glance, I do not see any serious problem in this version... except it doesn't apply to Linus's tree. just one question for now. On 04/17, Ravi Bangoria wrote: > > @@ -941,6 +1091,9 @@ typedef bool

Re: [PATCH v3 6/9] trace_uprobe: Support SDT markers having reference count (semaphore)

Hi Masami, On 05/07/2018 09:26 PM, Masami Hiramatsu wrote: > On Mon, 7 May 2018 13:51:21 +0530 > Ravi Bangoria wrote: > >> Hi Masami, >> >> On 05/04/2018 07:51 PM, Ravi Bangoria wrote: > +} > + > +static void sdt_increment_ref_ctr(struct trace_uprobe *tu)

Re: [PATCH v3 6/9] trace_uprobe: Support SDT markers having reference count (semaphore)

Hi Masami, On 05/07/2018 09:26 PM, Masami Hiramatsu wrote: > On Mon, 7 May 2018 13:51:21 +0530 > Ravi Bangoria wrote: > >> Hi Masami, >> >> On 05/04/2018 07:51 PM, Ravi Bangoria wrote: > +} > + > +static void sdt_increment_ref_ctr(struct trace_uprobe *tu) > +{ > + struct

Re: [PATCH v3 6/9] trace_uprobe: Support SDT markers having reference count (semaphore)

Masami Hiramatsu wrote: On Mon, 7 May 2018 13:51:21 +0530 Ravi Bangoria wrote: BTW, same issue exists for normal uprobe. If uprobe_mmap() fails, there is no feedback to trace_uprobe and no warnigns in dmesg as well !! There was a patch by Naveen to warn such

Re: [PATCH v3 6/9] trace_uprobe: Support SDT markers having reference count (semaphore)

Masami Hiramatsu wrote: On Mon, 7 May 2018 13:51:21 +0530 Ravi Bangoria wrote: BTW, same issue exists for normal uprobe. If uprobe_mmap() fails, there is no feedback to trace_uprobe and no warnigns in dmesg as well !! There was a patch by Naveen to warn such failures in dmesg but that didn't

Re: [PATCH v3 6/9] trace_uprobe: Support SDT markers having reference count (semaphore)

On Mon, 7 May 2018 13:51:21 +0530 Ravi Bangoria wrote: > Hi Masami, > > On 05/04/2018 07:51 PM, Ravi Bangoria wrote: > > > >>> +} > >>> + > >>> +static void sdt_increment_ref_ctr(struct trace_uprobe *tu) > >>> +{ > >>> + struct uprobe_map_info *info; > >>> + > >>> +

Re: [PATCH v3 6/9] trace_uprobe: Support SDT markers having reference count (semaphore)

On Mon, 7 May 2018 13:51:21 +0530 Ravi Bangoria wrote: > Hi Masami, > > On 05/04/2018 07:51 PM, Ravi Bangoria wrote: > > > >>> +} > >>> + > >>> +static void sdt_increment_ref_ctr(struct trace_uprobe *tu) > >>> +{ > >>> + struct uprobe_map_info *info; > >>> + > >>> +

Re: [PATCH v3 6/9] trace_uprobe: Support SDT markers having reference count (semaphore)

Hi Masami, On 05/04/2018 07:51 PM, Ravi Bangoria wrote: > >>> +} >>> + >>> +static void sdt_increment_ref_ctr(struct trace_uprobe *tu) >>> +{ >>> + struct uprobe_map_info *info; >>> + >>> + uprobe_down_write_dup_mmap(); >>> + info = uprobe_build_map_info(tu->inode->i_mapping, >>> +

Re: [PATCH v3 6/9] trace_uprobe: Support SDT markers having reference count (semaphore)

Hi Masami, On 05/04/2018 07:51 PM, Ravi Bangoria wrote: > >>> +} >>> + >>> +static void sdt_increment_ref_ctr(struct trace_uprobe *tu) >>> +{ >>> + struct uprobe_map_info *info; >>> + >>> + uprobe_down_write_dup_mmap(); >>> + info = uprobe_build_map_info(tu->inode->i_mapping, >>> +

Re: [PATCH v3 6/9] trace_uprobe: Support SDT markers having reference count (semaphore)

Hi Masami, On 05/04/2018 10:18 AM, Masami Hiramatsu wrote: >> +void uprobe_down_write_dup_mmap(void) >> +{ >> +percpu_down_write(_mmap_sem); >> +} >> + >> +void uprobe_up_write_dup_mmap(void) >> +{ >> +percpu_up_write(_mmap_sem); >> +} >> + > I'm not sure why these hunks are not done in

Re: [PATCH v3 6/9] trace_uprobe: Support SDT markers having reference count (semaphore)

Hi Masami, On 05/04/2018 10:18 AM, Masami Hiramatsu wrote: >> +void uprobe_down_write_dup_mmap(void) >> +{ >> +percpu_down_write(_mmap_sem); >> +} >> + >> +void uprobe_up_write_dup_mmap(void) >> +{ >> +percpu_up_write(_mmap_sem); >> +} >> + > I'm not sure why these hunks are not done in

Re: [PATCH v3 6/9] trace_uprobe: Support SDT markers having reference count (semaphore)

Hi Ravi, I have some comments, please see below. On Tue, 17 Apr 2018 10:02:41 +0530 Ravi Bangoria wrote:\ > diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h > index 7bd2760..2db3ed1 100644 > --- a/include/linux/uprobes.h > +++

Re: [PATCH v3 6/9] trace_uprobe: Support SDT markers having reference count (semaphore)

Hi Ravi, I have some comments, please see below. On Tue, 17 Apr 2018 10:02:41 +0530 Ravi Bangoria wrote:\ > diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h > index 7bd2760..2db3ed1 100644 > --- a/include/linux/uprobes.h > +++ b/include/linux/uprobes.h > @@ -122,6 +122,8 @@

[PATCH v3 6/9] trace_uprobe: Support SDT markers having reference count (semaphore)

From: Ravi Bangoria Userspace Statically Defined Tracepoints[1] are dtrace style markers inside userspace applications. Applications like PostgreSQL, MySQL, Pthread, Perl, Python, Java, Ruby, Node.js, libvirt, QEMU, glib etc have these markers embedded in them. These

[PATCH v3 6/9] trace_uprobe: Support SDT markers having reference count (semaphore)

From: Ravi Bangoria Userspace Statically Defined Tracepoints[1] are dtrace style markers inside userspace applications. Applications like PostgreSQL, MySQL, Pthread, Perl, Python, Java, Ruby, Node.js, libvirt, QEMU, glib etc have these markers embedded in them. These markers are added by