From: Nathan Lynch <nathanl@linux.ibm.com>
To: Kajol Jain <kjain@linux.ibm.com>
Cc: ravi.bangoria@linux.ibm.com, maddy@linux.vnet.ibm.com,
anju@linux.vnet.ibm.com, peterz@infradead.org,
gregkh@linuxfoundation.org, suka@us.ibm.com,
alexander.shishkin@linux.intel.com, mingo@kernel.org,
mpetlan@redhat.com, yao.jin@linux.intel.com, ak@linux.intel.com,
mamatha4@linux.vnet.ibm.com, acme@kernel.org, jmario@redhat.com,
namhyung@kernel.org, linuxppc-dev@lists.ozlabs.org,
jolsa@kernel.org, kan.liang@linux.intel.com
Subject: Re: [PATCH v8 5/5] powerpc/hv-24x7: Update post_mobility_fixup() to handle migration
Date: Mon, 11 May 2020 14:40:03 -0500 [thread overview]
Message-ID: <87eerq2rcc.fsf@linux.ibm.com> (raw)
In-Reply-To: <20200506110737.14904-6-kjain@linux.ibm.com>
Hello,
Kajol Jain <kjain@linux.ibm.com> writes:
> Function 'read_sys_info_pseries()' is added to get system parameter
> values like number of sockets and chips per socket.
> and it gets these details via rtas_call with token
> "PROCESSOR_MODULE_INFO".
>
> Incase lpar migrate from one system to another, system
> parameter details like chips per sockets or number of sockets might
> change. So, it needs to be re-initialized otherwise, these values
> corresponds to previous system values.
> This patch adds a call to 'read_sys_info_pseries()' from
> 'post-mobility_fixup()' to re-init the physsockets and physchips values
>
> Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
> ---
> arch/powerpc/platforms/pseries/mobility.c | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
Please cc me on patches for this code, thanks.
I see no technical problems with how this patch handles partition
migration. However:
"Update post_mobility_fixup() to handle migration" is not an appropriate
summary for this change. post_mobility_fixup() already handles
migration. A better summary would be
"powerpc/pseries: update hv-24x7 info after migration"
> diff --git a/arch/powerpc/platforms/pseries/mobility.c b/arch/powerpc/platforms/pseries/mobility.c
> index b571285f6c14..0fb8f1e6e9d2 100644
> --- a/arch/powerpc/platforms/pseries/mobility.c
> +++ b/arch/powerpc/platforms/pseries/mobility.c
> @@ -42,6 +42,12 @@ struct update_props_workarea {
> #define MIGRATION_SCOPE (1)
> #define PRRN_SCOPE -2
>
> +#ifdef CONFIG_HV_PERF_CTRS
> +void read_sys_info_pseries(void);
> +#else
> +static inline void read_sys_info_pseries(void) { }
> +#endif
This should go in a header.
> static int mobility_rtas_call(int token, char *buf, s32 scope)
> {
> int rc;
> @@ -371,6 +377,16 @@ void post_mobility_fixup(void)
> /* Possibly switch to a new RFI flush type */
> pseries_setup_rfi_flush();
>
> + /*
> + * In case an Lpar migrates from one system to another, system
> + * parameter details like chips per sockets, cores per chip and
> + * number of sockets details might change.
> + * So, they needs to be re-initialized otherwise the
> + * values will correspond to the previous system.
> + * Call read_sys_info_pseries() to reinitialise the values.
> + */
This is needlessly verbose; any literate reader of this code knows this
is used immediately after resuming from a suspend (migration). If you
give your hook a more descriptive name, the comment becomes unnecessary.
> + read_sys_info_pseries();
> +
next prev parent reply other threads:[~2020-05-11 19:42 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-06 11:07 [PATCH v8 0/5] powerpc/hv-24x7: Expose chip/sockets info to add json file metric support for the hv_24x7 socket/chip level events Kajol Jain
2020-05-06 11:07 ` [PATCH v8 1/5] powerpc/perf/hv-24x7: Fix inconsistent output values incase multiple hv-24x7 events run Kajol Jain
2020-05-06 11:07 ` [PATCH v8 2/5] powerpc/hv-24x7: Add rtas call in hv-24x7 driver to get processor details Kajol Jain
2020-05-11 21:07 ` Nathan Lynch
2020-05-18 5:32 ` kajoljain
2020-05-06 11:07 ` [PATCH v8 3/5] powerpc/hv-24x7: Add sysfs files inside hv-24x7 device to show " Kajol Jain
2020-05-06 11:07 ` [PATCH v8 4/5] Documentation/ABI: Add ABI documentation for chips and sockets Kajol Jain
2020-05-06 11:07 ` [PATCH v8 5/5] powerpc/hv-24x7: Update post_mobility_fixup() to handle migration Kajol Jain
2020-05-08 22:10 ` kbuild test robot
2020-05-11 19:40 ` Nathan Lynch [this message]
2020-05-13 6:20 ` kajoljain
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