Hi Linus,
The following changes since commit 1613e604df0cd359cf2a7fbd9be7a0bcfacfabd0:
Linux 6.10-rc1 (2024-05-26 15:20:12 -0700)
are available in the Git repository at:
https://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock
for you to fetch changes up to 3ac36aa7307363b7247ccb6f6a804e11496b2b36:
x86/mm/numa: Use NUMA_NO_NODE when calling memblock_set_node() (2024-06-06 22:20:39 +0300)
----------------------------------------------------------------
Jan Beulich (2):
memblock: make memblock_set_node() also warn about use of MAX_NUMNODES
x86/mm/numa: Use NUMA_NO_NODE when calling memblock_set_node()
arch/x86/mm/numa.c | 6 +++---
mm/memblock.c | 4 ++++
2 files changed, 7 insertions(+), 3 deletions(-)
--
Sincerely yours,
Mike.
On Thu, 13 Jun 2024 at 07:11, Mike Rapoport <[email protected]> wrote:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock
What's going on? This is the second pull request recently that doesn't
actually mention where to pull from.
I can do a "git ls-remote", and I see that you have a tag called
"fixes-2024-06-13" that then points to the commit you mention:
> for you to fetch changes up to 3ac36aa7307363b7247ccb6f6a804e11496b2b36:
but that tag name isn't actually in the pull request.
Is there some broken scripting that people have started using (or have
been using for a while and was recently broken)?
Linus
On Thu, 13 Jun 2024 at 10:09, Linus Torvalds
<[email protected]> wrote:
>
> Is there some broken scripting that people have started using (or have
> been using for a while and was recently broken)?
... and then when I actually pull the code, I note that the problem
where it checked _one_ bogus value has just been replaced with
checking _another_ bogus value.
Christ.
What if people use a node ID that is simply outside the range
entirely, instead of one of those special node IDs?
And now for memblock_set_node() you should apparently use NUMA_NO_NODE
to not get a warning, but for memblock_set_region_node() apparently
the right random constant to use is MAX_NUMNODES.
Does *any* of this make sense? No.
How about instead of having two random constants - and not having any
range checking that I see - just have *one* random constant for "I
have no range", call that NUMA_NO_NODE, and then have a simple helper
for "do I have a valid range", and make that be
static inline bool numa_valid_node(int nid)
{ return (unsigned int)nid < MAX_NUMNODES; }
or something like that? Notice that now *all* of
- NUMA_NO_NODE (explicitly no node)
- MAX_NUMNODES (randomly used no node)
- out of range node (who knows wth firmware tables do?)
will get the same result from that "numa_valid_node()" function.
And at that point you don't need to care, you don't need to warn, and
you don't need to have these insane rules where "sometimes you *HAVE*
to use NUMA_NO_NODE, or we warn, in other cases MAX_NUMNODES is the
thing".
Please? IOW, instead of adding a warning for fragile code, then change
some caller to follow the new rules, JUST FIX THE STUPID FRAGILITY!
Or hey, just do
#define NUMA_NO_NODE MAX_NUMNODES
and have two names for the *same* constant, instead fo having two
different constants with strange semantic differences that seem to
make no sense and where the memblock code itself seems to go
back-and-forth on it in different contexts.
Linus
The pull request you sent on Thu, 13 Jun 2024 17:09:36 +0300:
> https://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock refs/heads/master
has been merged into torvalds/linux.git:
https://git.kernel.org/torvalds/c/3572597ca844f625a3c9ba629ed0872b64c16179
Thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/prtracker.html
On 13.06.2024 19:38, Linus Torvalds wrote:
> On Thu, 13 Jun 2024 at 10:09, Linus Torvalds
> <[email protected]> wrote:
>>
>> Is there some broken scripting that people have started using (or have
>> been using for a while and was recently broken)?
>
> ... and then when I actually pull the code, I note that the problem
> where it checked _one_ bogus value has just been replaced with
> checking _another_ bogus value.
>
> Christ.
>
> What if people use a node ID that is simply outside the range
> entirely, instead of one of those special node IDs?
>
> And now for memblock_set_node() you should apparently use NUMA_NO_NODE
> to not get a warning, but for memblock_set_region_node() apparently
> the right random constant to use is MAX_NUMNODES.
>
> Does *any* of this make sense? No.
>
> How about instead of having two random constants - and not having any
> range checking that I see - just have *one* random constant for "I
> have no range", call that NUMA_NO_NODE,
Just to mention it - my understanding is that this is an ongoing process
heading in this very direction. I'm not an mm person at all, so I can't
tell why the conversion wasn't done / can't be done all in one go.
Jan
> and then have a simple helper
> for "do I have a valid range", and make that be
>
> static inline bool numa_valid_node(int nid)
> { return (unsigned int)nid < MAX_NUMNODES; }
>
> or something like that? Notice that now *all* of
>
> - NUMA_NO_NODE (explicitly no node)
>
> - MAX_NUMNODES (randomly used no node)
>
> - out of range node (who knows wth firmware tables do?)
>
> will get the same result from that "numa_valid_node()" function.
>
> And at that point you don't need to care, you don't need to warn, and
> you don't need to have these insane rules where "sometimes you *HAVE*
> to use NUMA_NO_NODE, or we warn, in other cases MAX_NUMNODES is the
> thing".
>
> Please? IOW, instead of adding a warning for fragile code, then change
> some caller to follow the new rules, JUST FIX THE STUPID FRAGILITY!
>
> Or hey, just do
>
> #define NUMA_NO_NODE MAX_NUMNODES
>
> and have two names for the *same* constant, instead fo having two
> different constants with strange semantic differences that seem to
> make no sense and where the memblock code itself seems to go
> back-and-forth on it in different contexts.
>
> Linus
On Fri, Jun 14, 2024 at 08:01:33AM +0200, Jan Beulich wrote:
> On 13.06.2024 19:38, Linus Torvalds wrote:
> > On Thu, 13 Jun 2024 at 10:09, Linus Torvalds
> > <[email protected]> wrote:
> >>
> >> Is there some broken scripting that people have started using (or have
> >> been using for a while and was recently broken)?
> >
> > ... and then when I actually pull the code, I note that the problem
> > where it checked _one_ bogus value has just been replaced with
> > checking _another_ bogus value.
> >
> > Christ.
> >
> > What if people use a node ID that is simply outside the range
> > entirely, instead of one of those special node IDs?
> >
> > And now for memblock_set_node() you should apparently use NUMA_NO_NODE
> > to not get a warning, but for memblock_set_region_node() apparently
> > the right random constant to use is MAX_NUMNODES.
> >
> > Does *any* of this make sense? No.
> >
> > How about instead of having two random constants - and not having any
> > range checking that I see - just have *one* random constant for "I
> > have no range", call that NUMA_NO_NODE,
>
> Just to mention it - my understanding is that this is an ongoing process
> heading in this very direction. I'm not an mm person at all, so I can't
> tell why the conversion wasn't done / can't be done all in one go.
Nah, it's an historical mess and my oversight.
> Jan
--
Sincerely yours,
Mike.
On Thu, Jun 13, 2024 at 10:38:28AM -0700, Linus Torvalds wrote:
> On Thu, 13 Jun 2024 at 10:09, Linus Torvalds
> <[email protected]> wrote:
> >
> > Is there some broken scripting that people have started using (or have
> > been using for a while and was recently broken)?
>
> ... and then when I actually pull the code, I note that the problem
> where it checked _one_ bogus value has just been replaced with
> checking _another_ bogus value.
>
> Christ.
>
> What if people use a node ID that is simply outside the range
> entirely, instead of one of those special node IDs?
>
> And now for memblock_set_node() you should apparently use NUMA_NO_NODE
> to not get a warning, but for memblock_set_region_node() apparently
> the right random constant to use is MAX_NUMNODES.
>
> Does *any* of this make sense? No.
>
> How about instead of having two random constants - and not having any
> range checking that I see - just have *one* random constant for "I
> have no range", call that NUMA_NO_NODE, and then have a simple helper
> for "do I have a valid range", and make that be
>
> static inline bool numa_valid_node(int nid)
> { return (unsigned int)nid < MAX_NUMNODES; }
>
> or something like that? Notice that now *all* of
>
> - NUMA_NO_NODE (explicitly no node)
>
> - MAX_NUMNODES (randomly used no node)
>
> - out of range node (who knows wth firmware tables do?)
>
> will get the same result from that "numa_valid_node()" function.
>
> And at that point you don't need to care, you don't need to warn, and
> you don't need to have these insane rules where "sometimes you *HAVE*
> to use NUMA_NO_NODE, or we warn, in other cases MAX_NUMNODES is the
> thing".
>
> Please? IOW, instead of adding a warning for fragile code, then change
> some caller to follow the new rules, JUST FIX THE STUPID FRAGILITY!
>
> Or hey, just do
>
> #define NUMA_NO_NODE MAX_NUMNODES
>
> and have two names for the *same* constant, instead fo having two
> different constants with strange semantic differences that seem to
> make no sense and where the memblock code itself seems to go
> back-and-forth on it in different contexts.
A single constant is likely to backfire because I remember seeing checks
like 'if (nid < 0)' so redefining NUMA_NO_NODE will require auditing all
those.
But a helper function works great.
I could only lightly test it as I don't have a fleet of machines with
variety of memory layouts, so I'm planning to push it into -next early next
week (with subject replaced by a more informative one)
From 319eddd74b372cae840782c7d53832ab30533a6b Mon Sep 17 00:00:00 2001
From: "Mike Rapoport (IBM)" <[email protected]>
Date: Fri, 14 Jun 2024 11:05:43 +0300
Subject: [PATCH] memblock: FIX THE STUPID FRAGILITY
Introduce numa_valid_node(nid) that verifies that nid is a valid node ID
and use that instead of comparing nid parameter with either NUMA_NO_NODE
or MAX_NUMNODES.
This makes the checks for valid node IDs consistent and more robust and
allows to get rid of multiple WARNings.
Suggested-by: Linus Torvalds <[email protected]>
Signed-off-by: Mike Rapoport (IBM) <[email protected]>
---
include/linux/numa.h | 5 +++++
mm/memblock.c | 28 +++++++---------------------
2 files changed, 12 insertions(+), 21 deletions(-)
diff --git a/include/linux/numa.h b/include/linux/numa.h
index 1d43371fafd2..eb19503604fe 100644
--- a/include/linux/numa.h
+++ b/include/linux/numa.h
@@ -15,6 +15,11 @@
#define NUMA_NO_NODE (-1)
#define NUMA_NO_MEMBLK (-1)
+static inline bool numa_valid_node(int nid)
+{
+ return nid >= 0 && nid < MAX_NUMNODES;
+}
+
/* optionally keep NUMA memory info available post init */
#ifdef CONFIG_NUMA_KEEP_MEMINFO
#define __initdata_or_meminfo
diff --git a/mm/memblock.c b/mm/memblock.c
index 08e9806b1cf9..e81fb68f7f88 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -754,7 +754,7 @@ bool __init_memblock memblock_validate_numa_coverage(unsigned long threshold_byt
/* calculate lose page */
for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
- if (nid == NUMA_NO_NODE)
+ if (!numa_valid_node(nid))
nr_pages += end_pfn - start_pfn;
}
@@ -1061,7 +1061,7 @@ static bool should_skip_region(struct memblock_type *type,
return false;
/* only memory regions are associated with nodes, check it */
- if (nid != NUMA_NO_NODE && nid != m_nid)
+ if (numa_valid_node(nid) && nid != m_nid)
return true;
/* skip hotpluggable memory regions if needed */
@@ -1118,10 +1118,6 @@ void __next_mem_range(u64 *idx, int nid, enum memblock_flags flags,
int idx_a = *idx & 0xffffffff;
int idx_b = *idx >> 32;
- if (WARN_ONCE(nid == MAX_NUMNODES,
- "Usage of MAX_NUMNODES is deprecated. Use NUMA_NO_NODE instead\n"))
- nid = NUMA_NO_NODE;
-
for (; idx_a < type_a->cnt; idx_a++) {
struct memblock_region *m = &type_a->regions[idx_a];
@@ -1215,9 +1211,6 @@ void __init_memblock __next_mem_range_rev(u64 *idx, int nid,
int idx_a = *idx & 0xffffffff;
int idx_b = *idx >> 32;
- if (WARN_ONCE(nid == MAX_NUMNODES, "Usage of MAX_NUMNODES is deprecated. Use NUMA_NO_NODE instead\n"))
- nid = NUMA_NO_NODE;
-
if (*idx == (u64)ULLONG_MAX) {
idx_a = type_a->cnt - 1;
if (type_b != NULL)
@@ -1303,7 +1296,7 @@ void __init_memblock __next_mem_pfn_range(int *idx, int nid,
if (PFN_UP(r->base) >= PFN_DOWN(r->base + r->size))
continue;
- if (nid == MAX_NUMNODES || nid == r_nid)
+ if (!numa_valid_node(nid) || nid == r_nid)
break;
}
if (*idx >= type->cnt) {
@@ -1339,10 +1332,6 @@ int __init_memblock memblock_set_node(phys_addr_t base, phys_addr_t size,
int start_rgn, end_rgn;
int i, ret;
- if (WARN_ONCE(nid == MAX_NUMNODES,
- "Usage of MAX_NUMNODES is deprecated. Use NUMA_NO_NODE instead\n"))
- nid = NUMA_NO_NODE;
-
ret = memblock_isolate_range(type, base, size, &start_rgn, &end_rgn);
if (ret)
return ret;
@@ -1452,9 +1441,6 @@ phys_addr_t __init memblock_alloc_range_nid(phys_addr_t size,
enum memblock_flags flags = choose_memblock_flags();
phys_addr_t found;
- if (WARN_ONCE(nid == MAX_NUMNODES, "Usage of MAX_NUMNODES is deprecated. Use NUMA_NO_NODE instead\n"))
- nid = NUMA_NO_NODE;
-
if (!align) {
/* Can't use WARNs this early in boot on powerpc */
dump_stack();
@@ -1467,7 +1453,7 @@ phys_addr_t __init memblock_alloc_range_nid(phys_addr_t size,
if (found && !memblock_reserve(found, size))
goto done;
- if (nid != NUMA_NO_NODE && !exact_nid) {
+ if (numa_valid_node(nid) && !exact_nid) {
found = memblock_find_in_range_node(size, align, start,
end, NUMA_NO_NODE,
flags);
@@ -1987,7 +1973,7 @@ static void __init_memblock memblock_dump(struct memblock_type *type)
end = base + size - 1;
flags = rgn->flags;
#ifdef CONFIG_NUMA
- if (memblock_get_region_node(rgn) != MAX_NUMNODES)
+ if (numa_valid_node(memblock_get_region_node(rgn)))
snprintf(nid_buf, sizeof(nid_buf), " on node %d",
memblock_get_region_node(rgn));
#endif
@@ -2181,7 +2167,7 @@ static void __init memmap_init_reserved_pages(void)
start = region->base;
end = start + region->size;
- if (nid == NUMA_NO_NODE || nid >= MAX_NUMNODES)
+ if (!numa_valid_node(nid))
nid = early_pfn_to_nid(PFN_DOWN(start));
reserve_bootmem_region(start, end, nid);
@@ -2272,7 +2258,7 @@ static int memblock_debug_show(struct seq_file *m, void *private)
seq_printf(m, "%4d: ", i);
seq_printf(m, "%pa..%pa ", ®->base, &end);
- if (nid != MAX_NUMNODES)
+ if (numa_valid_node(nid))
seq_printf(m, "%4d ", nid);
else
seq_printf(m, "%4c ", 'x');
--
2.43.0
> Linus
--
Sincerely yours,
Mike.
On Fri, 14 Jun 2024 at 01:20, Mike Rapoport <[email protected]> wrote:
>
> A single constant is likely to backfire because I remember seeing checks
> like 'if (nid < 0)' so redefining NUMA_NO_NODE will require auditing all
> those.
Yeah, fair enough.
> But a helper function works great.
Thanks, that patch looks like a nice improvement to me.
Linus