| Message ID | 20240523155641.2805411-4-yazen.ghannam@amd.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | AMD MCA interrupts rework | expand |
On Thu, May 23, 2024 at 10:56:35AM -0500, Yazen Ghannam wrote: > MCP count is currently incremented for any call to machine_check_poll(). > Therefore, the count includes calls from the timer, boot-time polling, > and interrupt handlers. > > Only increment the MCP count when called from the timer so as to avoid > double counting the interrupt handlers. Well, but, every time the function is called, we did poll the banks. Sure, the count is part of /proc/interrupts but we did poll the banks in those other cases too. So I think showing an accurate poll number is actually representing the truth, no matter where it is shown...
On 5/24/24 10:53 AM, Borislav Petkov wrote: > On Thu, May 23, 2024 at 10:56:35AM -0500, Yazen Ghannam wrote: >> MCP count is currently incremented for any call to machine_check_poll(). >> Therefore, the count includes calls from the timer, boot-time polling, >> and interrupt handlers. >> >> Only increment the MCP count when called from the timer so as to avoid >> double counting the interrupt handlers. > > Well, but, every time the function is called, we did poll the banks. > Sure, the count is part of /proc/interrupts but we did poll the banks in > those other cases too. So I think showing an accurate poll number is > actually representing the truth, no matter where it is shown... > Okay, fair enough. In this case, should we also increment the count in __mc_scan_banks()? Thanks, Yazen
On Mon, Jun 03, 2024 at 10:22:22AM -0400, Yazen Ghannam wrote:
> In this case, should we also increment the count in __mc_scan_banks()?
Well, that's called only in do_machine_check() and latter's not polling
the banks but called as a result of a #MC exception raised.
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c index 287108de210e..70c8df1a766a 100644 --- a/arch/x86/kernel/cpu/mce/core.c +++ b/arch/x86/kernel/cpu/mce/core.c @@ -683,8 +683,6 @@ void machine_check_poll(enum mcp_flags flags, mce_banks_t *b) struct mce m; int i; - this_cpu_inc(mce_poll_count); - mce_gather_info(&m, NULL); if (flags & MCP_TIMESTAMP) @@ -1667,8 +1665,10 @@ static void mce_timer_fn(struct timer_list *t) iv = __this_cpu_read(mce_next_interval); - if (mce_available(this_cpu_ptr(&cpu_info))) + if (mce_available(this_cpu_ptr(&cpu_info))) { + this_cpu_inc(mce_poll_count); mc_poll_banks(); + } /* * Alert userspace if needed. If we logged an MCE, reduce the polling
MCP count is currently incremented for any call to machine_check_poll(). Therefore, the count includes calls from the timer, boot-time polling, and interrupt handlers. Only increment the MCP count when called from the timer so as to avoid double counting the interrupt handlers. Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com> --- arch/x86/kernel/cpu/mce/core.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)