LKML Archive on
help / color / mirror / Atom feed
From: Sudeep Holla <>
To: Xiongfeng Wang <>
Cc:,,,,,,,, Sudeep Holla <>
Subject: Re: [PATCH] ACPI / PPTT: get PPTT table in the first beginning
Date: Tue, 20 Jul 2021 14:37:51 +0100	[thread overview]
Message-ID: <20210720133751.u6k6bdm7qco3gn65@bogus> (raw)
In-Reply-To: <>

On Tue, Jul 20, 2021 at 07:26:35PM +0800, Xiongfeng Wang wrote:
> When I added might_sleep() in down_timeout(), I got the following

Sorry it is not clear if you are able to reproduce this issue without
any other modifications in the mainline kernel ?

> Calltrace:
> [    8.775671] BUG: sleeping function called from invalid context at kernel/locking/semaphore.c:160
> [    8.777070] in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 14, name: cpuhp/0

From this I guess you are adding sleep after raw_spin_lock_irqsave
in down_timeout(kernel/locking/semaphore.c).

> It is because generic_exec_single() will disable local irq before
> calling _init_cache_level(). _init_cache_level() use acpi_get_table() to
> get the PPTT table, but this function could schedule out.
> To fix this issue, we use a static pointer to record the mapped PPTT
> table in the first beginning. Later, we use that pointer to reference
> the PPTT table in acpi_find_last_cache_level(). We also modify other
> functions in pptt.c to use the pointer to reference PPTT table.

I don't follow this change at all.


  reply	other threads:[~2021-07-20 13:41 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-20 11:26 Xiongfeng Wang
2021-07-20 13:37 ` Sudeep Holla [this message]
2021-07-21  1:25   ` Xiongfeng Wang
2021-09-01  7:29   ` Zenghui Yu
2021-09-01  8:15     ` Hanjun Guo
2021-09-01  8:49       ` Zenghui Yu

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210720133751.u6k6bdm7qco3gn65@bogus \ \ \ \ \ \ \ \ \ \ \
    --subject='Re: [PATCH] ACPI / PPTT: get PPTT table in the first beginning' \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).