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Message-ID: <f99153be-2636-60a3-2630-c592cc230b53@infradead.org>
Date:   Mon, 23 May 2022 13:49:38 -0700
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Subject: Re: [RFC 2/6] PM: Hibernate: Add option to disable disk offset
 randomization
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To:     Vivek Kumar <quic_vivekuma@quicinc.com>, corbet@lwn.net,
        catalin.marinas@arm.com, will@kernel.org, tglx@linutronix.de,
        maz@kernel.org, axboe@kernel.dk, rafael@kernel.org,
        akpm@linux-foundation.org, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-block@vger.kernel.org, linux-pm@vger.kernel.org,
        linux-mm@kvack.org
Cc:     len.brown@intel.com, pavel@ucw.cz, paulmck@kernel.org, bp@suse.de,
        keescook@chromium.org, songmuchun@bytedance.com,
        damien.lemoal@opensource.wdc.com, pasha.tatashin@soleen.com,
        tabba@google.com, ardb@kernel.org, tsoni@quicinc.com,
        quic_psodagud@quicinc.com, quic_svaddagi@quicinc.com,
        Prasanna Kumar <quic_kprasan@quicinc.com>
References: <1652860121-24092-1-git-send-email-quic_vivekuma@quicinc.com>
 <1652860121-24092-3-git-send-email-quic_vivekuma@quicinc.com>
From:   Randy Dunlap <rdunlap@infradead.org>
In-Reply-To: <1652860121-24092-3-git-send-email-quic_vivekuma@quicinc.com>
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On 5/18/22 00:48, Vivek Kumar wrote:
> Add a kernel parameter to disable the disk offset randomization
> for SSD devices in which such feature is available at the
> firmware level. This is helpful in improving hibernation
> resume time.
> 
> Signed-off-by: Vivek Kumar <quic_vivekuma@quicinc.com>
> Signed-off-by: Prasanna Kumar <quic_kprasan@quicinc.com>
> ---
>  Documentation/admin-guide/kernel-parameters.txt | 11 +++++++++++
>  kernel/power/swap.c                             |  9 +++++++++
>  2 files changed, 20 insertions(+)
> 
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 666ade9..06b4f10 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -5192,6 +5192,17 @@
>  			Useful for devices that are detected asynchronously
>  			(e.g. USB and MMC devices).
>  
> +	noswap_randomize
> +			Kernel uses random disk offsets to help with wear-levelling

			                                             wear-leveling

> +			of SSD devices, while saving the hibernation snapshot image to
> +			disk. Use this parameter to disable this feature for SSD
> +			devices in scenarios when, such randomization is addressed at

			               no comma  ^

> +			the firmware level and hibenration image is not re-generated

			                       hibernation

> +			frequently.
> +			(Useful for improving hibernation resume time as snapshot pages
> +			are available in disk serially and can be read in bigger chunks
> +			without seeking)
> +
>  	retain_initrd	[RAM] Keep initrd memory after extraction
>  
>  	rfkill.default_state=


-- 
~Randy