> - Quickly identify all user processes mapping a given page.
Can be done with /proc/*/pagemap today. Maybe it's not "quick"
because it won't use the rmap chains, but is that a serious
issue?
> - Determine if and where the kernel maps the page, which is also
> important given the opportunity to r
On Wed, Nov 20, 2024 at 8:14 AM Pasha Tatashin
wrote:
>
> On Tue, Nov 19, 2024 at 2:36 PM Yosry Ahmed wrote:
> >
> > On Tue, Nov 19, 2024 at 11:30 AM Pasha Tatashin
> > wrote:
> > >
> > > On Tue, Nov 19, 2024 at 1:23 PM Roman Gushchin
> > > wrote:
> > > >
> > > > On Tue, Nov 19, 2024 at 10:08:
> > /* Use static buffer, for the caller is holding oom_lock. */
> > static char buf[PAGE_SIZE];
> >
> > seq_buf_init(&s, buf, sizeof(buf));
> > memory_stat_format(memcg, &s);
> > seq_buf_do_printk(&s, KERN_INFO);
> > }
> >
> > This is a callosal
On Wed, Nov 20, 2024 at 10:29 AM Andi Kleen wrote:
>
> Pasha Tatashin writes:
>
> > Page Detective is a new kernel debugging tool that provides detailed
> > information about the usage and mapping of physical memory pages.
> >
> > It is often known that a particular page is corrupted, but it is h
On Tue, Nov 19, 2024 at 2:36 PM Yosry Ahmed wrote:
>
> On Tue, Nov 19, 2024 at 11:30 AM Pasha Tatashin
> wrote:
> >
> > On Tue, Nov 19, 2024 at 1:23 PM Roman Gushchin
> > wrote:
> > >
> > > On Tue, Nov 19, 2024 at 10:08:36AM -0500, Pasha Tatashin wrote:
> > > > On Mon, Nov 18, 2024 at 8:09 PM G
Pasha Tatashin writes:
> Page Detective is a new kernel debugging tool that provides detailed
> information about the usage and mapping of physical memory pages.
>
> It is often known that a particular page is corrupted, but it is hard to
> extract more information about such a page from live sys
On Tue, Nov 19, 2024 at 11:35:47AM -0800, Yosry Ahmed wrote:
> On Tue, Nov 19, 2024 at 11:30 AM Pasha Tatashin
> wrote:
> >
> > On Tue, Nov 19, 2024 at 1:23 PM Roman Gushchin
> > wrote:
> > >
> > > On Tue, Nov 19, 2024 at 10:08:36AM -0500, Pasha Tatashin wrote:
> > > > On Mon, Nov 18, 2024 at 8:
On Tue, Nov 19, 2024 at 11:30 AM Pasha Tatashin
wrote:
>
> On Tue, Nov 19, 2024 at 1:23 PM Roman Gushchin
> wrote:
> >
> > On Tue, Nov 19, 2024 at 10:08:36AM -0500, Pasha Tatashin wrote:
> > > On Mon, Nov 18, 2024 at 8:09 PM Greg KH
> > > wrote:
> > > >
> > > > On Mon, Nov 18, 2024 at 05:08:42
On Tue, Nov 19, 2024 at 1:23 PM Roman Gushchin wrote:
>
> On Tue, Nov 19, 2024 at 10:08:36AM -0500, Pasha Tatashin wrote:
> > On Mon, Nov 18, 2024 at 8:09 PM Greg KH wrote:
> > >
> > > On Mon, Nov 18, 2024 at 05:08:42PM -0500, Pasha Tatashin wrote:
> > > > Additionally, using crash/drgn is not fe
On Tue, Nov 19, 2024 at 10:08:36AM -0500, Pasha Tatashin wrote:
> On Mon, Nov 18, 2024 at 8:09 PM Greg KH wrote:
> >
> > On Mon, Nov 18, 2024 at 05:08:42PM -0500, Pasha Tatashin wrote:
> > > Additionally, using crash/drgn is not feasible for us at this time, it
> > > requires keeping external tool
On Tue, Nov 19, 2024 at 01:52:00PM +0100, Jann Horn wrote:
> > I will take reference, as we already do that for memcg purpose, but
> > have not included dump_page().
>
> Note that taking a reference on the page does not make all of
> dump_page() fine; in particular, my understanding is that
> foli
On Tue, Nov 19, 2024 at 4:14 PM Pasha Tatashin
wrote:
> On Tue, Nov 19, 2024 at 7:52 AM Jann Horn wrote:
> > On Tue, Nov 19, 2024 at 2:30 AM Pasha Tatashin
> > wrote:
> > > > Can you point me to where a refcounted reference to the page comes
> > > > from when page_detective_metadata() calls dump
On Mon, Nov 18, 2024 at 8:09 PM Greg KH wrote:
>
> On Mon, Nov 18, 2024 at 05:08:42PM -0500, Pasha Tatashin wrote:
> > Additionally, using crash/drgn is not feasible for us at this time, it
> > requires keeping external tools on our hosts, also it requires
> > approval and a security review for ea
On Tue, Nov 19, 2024 at 7:52 AM Jann Horn wrote:
>
> On Tue, Nov 19, 2024 at 2:30 AM Pasha Tatashin
> wrote:
> > > Can you point me to where a refcounted reference to the page comes
> > > from when page_detective_metadata() calls dump_page_lvl()?
> >
> > I am sorry, I remembered incorrectly, we a
On Tue, Nov 19, 2024 at 2:30 AM Pasha Tatashin
wrote:
> > Can you point me to where a refcounted reference to the page comes
> > from when page_detective_metadata() calls dump_page_lvl()?
>
> I am sorry, I remembered incorrectly, we are getting reference right
> after dump_page_lvl() in page_detec
> Can you point me to where a refcounted reference to the page comes
> from when page_detective_metadata() calls dump_page_lvl()?
I am sorry, I remembered incorrectly, we are getting reference right
after dump_page_lvl() in page_detective_memcg() -> folio_try_get(); I
will move the folio_try_get()
On Mon, Nov 18, 2024 at 05:08:42PM -0500, Pasha Tatashin wrote:
> Additionally, using crash/drgn is not feasible for us at this time, it
> requires keeping external tools on our hosts, also it requires
> approval and a security review for each script before deployment in
> our fleet.
So it's ok to
On Mon, Nov 18, 2024 at 11:24 PM Pasha Tatashin
wrote:
> On Mon, Nov 18, 2024 at 7:54 AM Jann Horn wrote:
> >
> > On Mon, Nov 18, 2024 at 12:17 PM Lorenzo Stoakes
> > wrote:
> > > On Sat, Nov 16, 2024 at 05:59:16PM +, Pasha Tatashin wrote:
> > > > It operates through the Linux debugfs interf
On Mon, Nov 18, 2024 at 7:54 AM Jann Horn wrote:
>
> On Mon, Nov 18, 2024 at 12:17 PM Lorenzo Stoakes
> wrote:
> > On Sat, Nov 16, 2024 at 05:59:16PM +, Pasha Tatashin wrote:
> > > It operates through the Linux debugfs interface, with two files: "virt"
> > > and "phys".
> > >
> > > The "virt"
On Mon, Nov 18, 2024 at 2:11 PM Roman Gushchin wrote:
>
> On Sat, Nov 16, 2024 at 05:59:16PM +, Pasha Tatashin wrote:
> > Page Detective is a new kernel debugging tool that provides detailed
> > information about the usage and mapping of physical memory pages.
> >
> > It is often known that a
On Sat, Nov 16, 2024 at 05:59:16PM +, Pasha Tatashin wrote:
> Page Detective is a new kernel debugging tool that provides detailed
> information about the usage and mapping of physical memory pages.
>
> It is often known that a particular page is corrupted, but it is hard to
> extract more inf
On Mon, Nov 18, 2024 at 12:17 PM Lorenzo Stoakes
wrote:
> On Sat, Nov 16, 2024 at 05:59:16PM +, Pasha Tatashin wrote:
> > It operates through the Linux debugfs interface, with two files: "virt"
> > and "phys".
> >
> > The "virt" file takes a virtual address and PID and outputs information
> >
On Sat, Nov 16, 2024 at 05:59:16PM +, Pasha Tatashin wrote:
> Page Detective is a new kernel debugging tool that provides detailed
> information about the usage and mapping of physical memory pages.
>
> It is often known that a particular page is corrupted, but it is hard to
> extract more info
Page Detective is a new kernel debugging tool that provides detailed
information about the usage and mapping of physical memory pages.
It is often known that a particular page is corrupted, but it is hard to
extract more information about such a page from live system. Examples
are:
- Checksum fai
24 matches
Mail list logo
