This deletes the early boot messages in dmesg:
/var/log # head dmesg
[ 3.114274] random: get_random_u32 called from
allocate_slab+0x144/0x480 with crng_init=0
[ 3.114286] random: get_random_u32 called from
allocate_slab+0x144/0x480 with crng_init=0
[ 3.114291] random: get_random_u32 called from
allocate_slab+0x144/0x480 with crng_init=0
[ 3.114297] random: get_random_u32 called from
allocate_slab+0x144/0x480 with crng_init=0
[ 3.114304] random: get_random_u32 called from
allocate_slab+0x144/0x480 with crng_init=0
[ 3.114315] random: get_random_u32 called from
allocate_slab+0x144/0x480 with crng_init=0
[ 3.114323] random: get_random_u32 called from
allocate_slab+0x144/0x480 with crng_init=0
[ 3.114329] random: get_random_u32 called from
allocate_slab+0x144/0x480 with crng_init=0
[ 3.114333] random: get_random_u32 called from
allocate_slab+0x144/0x480 with crng_init=0
[ 3.114345] random: get_random_u32 called from
allocate_slab+0x144/0x480 with crng_init=0
5.18.0 was fine
--
Toralf
Hi Toralf,
On Mon, May 30, 2022 at 11:24:55AM +0200, Toralf Förster wrote:
> This deletes the early boot messages in dmesg:
>
> /var/log # head dmesg
> [ 3.114274] random: get_random_u32 called from
> allocate_slab+0x144/0x480 with crng_init=0
> [ 3.114286] random: get_random_u32 called from
> allocate_slab+0x144/0x480 with crng_init=0
> [ 3.114291] random: get_random_u32 called from
> allocate_slab+0x144/0x480 with crng_init=0
> [ 3.114297] random: get_random_u32 called from
> allocate_slab+0x144/0x480 with crng_init=0
> [ 3.114304] random: get_random_u32 called from
> allocate_slab+0x144/0x480 with crng_init=0
> [ 3.114315] random: get_random_u32 called from
> allocate_slab+0x144/0x480 with crng_init=0
> [ 3.114323] random: get_random_u32 called from
> allocate_slab+0x144/0x480 with crng_init=0
> [ 3.114329] random: get_random_u32 called from
> allocate_slab+0x144/0x480 with crng_init=0
> [ 3.114333] random: get_random_u32 called from
> allocate_slab+0x144/0x480 with crng_init=0
> [ 3.114345] random: get_random_u32 called from
> allocate_slab+0x144/0x480 with crng_init=0
This was simplified here:
https://lore.kernel.org/lkml/[email protected]/
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=cc1e127bfa95b5fb2f9307e7168bf8b2b45b4c5e
I'm happy to consider other heuristics than the one there if you find
this one problematic. But I think as a debug option, the current
behavior encapsulates well what somebody might want to know when
debugging a kernel. Either way, please let me know if this poses a
problem for you.
Jason
On 2022-05-30, Toralf Förster <[email protected]> wrote:
> On 5/30/22 11:24, Toralf Förster wrote:
>> This deletes the early boot messages in dmesg:
>
> changing CONFIG_LOG_BUF_SHIFT=18 to CONFIG_LOG_BUF_SHIFT=20 helps, but
> nevertheless:
FWIW, you can also use the boot argument "log_buf_len" to dynamically
allocate the dmesg buffer at boot.
For example: log_buf_len=16M
This is usually more convenient than reconfiguring/rebuilding your
kernel.
John Ogness
On 5/30/22 21:47, Jason A. Donenfeld wrote:
> This was simplified here:
>
> https://lore.kernel.org/lkml/[email protected]/
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=cc1e127bfa95b5fb2f9307e7168bf8b2b45b4c5e
Ah ok, understood the rationale behind that.
Thx.
--
Toralf
On 5/30/22 21:52, John Ogness wrote:
> FWIW, you can also use the boot argument "log_buf_len" to dynamically
> allocate the dmesg buffer at boot.
indeed.
Thx.
--
Toralf
On 5/30/22 11:24, Toralf Förster wrote:
> This deletes the early boot messages in dmesg:
>
Well,
changing CONFIG_LOG_BUF_SHIFT=18 to CONFIG_LOG_BUF_SHIFT=20 helps, but
nevertheless:
$ grep get_random_u dmesg-5.18.1 | wc
5541 38787 440908
For 5.15.44 there's no similar effect in dmesg after upgrading the kernel.
--
Toralf