linux-kernel - Re: [PATCH v4 3/5] x86/sgx: Optimize the free_cnt count in sgx_epc

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Message-ID: <b801ad31-5138-c68d-df9f-30f452cc3c4b@linux.alibaba.com>
Date:   Thu, 11 Feb 2021 14:05:56 +0800
From:   Tianjia Zhang <tianjia.zhang@...ux.alibaba.com>
To:     Jarkko Sakkinen <jarkko@...nel.org>
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        "H. Peter Anvin" <hpa@...or.com>,
        Sean Christopherson <seanjc@...gle.com>,
        Shuah Khan <shuah@...nel.org>, x86@...nel.org,
        linux-sgx@...r.kernel.org, linux-kselftest@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Jia Zhang <zhang.jia@...ux.alibaba.com>
Subject: Re: [PATCH v4 3/5] x86/sgx: Optimize the free_cnt count in
 sgx_epc_section



On 2/3/21 5:54 AM, Jarkko Sakkinen wrote:
> On Mon, Feb 01, 2021 at 09:26:51PM +0800, Tianjia Zhang wrote:
>> 'section->free_cnt' represents the free page in sgx_epc_section,
>> which is assigned once after initialization. In fact, just after the
>> initialization is completed, the pages are in the init_laundry_list
>> list and cannot be allocated. This needs to be recovered by EREMOVE
>> of function sgx_sanitize_section() before it can be used as a page
>> that can be allocated. The sgx_sanitize_section() will be called in
>> the kernel thread ksgxd.
>>
>> This patch moves the initialization of 'section->free_cnt' from the
>> initialization function sgx_setup_epc_section() to the function
>> sgx_sanitize_section(), and then accumulates the count after the
>> successful execution of EREMOVE. This seems to be more reasonable,
>> free_cnt will also truly reflect the allocatable free pages in EPC.
>>
>> Sined-off-by: Tianjia Zhang <tianjia.zhang@...ux.alibaba.com>
>> Reviewed-by: Sean Christopherson <seanjc@...gle.com>
> 
> I just copy-paste my earlier response to save time sice you  seem
> to save time by ignoring it and spamming with the same obviously
> illegit patch.
> 
> https://lore.kernel.org/linux-sgx/YBGlodsOaX4cWAtl@kernel.org/
> 
> /Jarkko
> 

Sorry for the late reply, I already responded in the original email.

Best regards,
Tianjia