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Miller" References: <20200511204150.27858-5-will@kernel.org> <20200517000050.GA87467@roeck-us.net> <20200517000750.GA157503@roeck-us.net> <20200518083715.GA31383@willie-the-truck> <20200520170306.GG1118872@kernel.org> <6034a1b5-d4f6-c836-142c-9b3b06db3246@roeck-us.net> <20200520195110.GH1118872@kernel.org> <20200524123256.GN1118872@kernel.org> <20200526132634.GC27166@willie-the-truck> <20200526140126.GD27166@willie-the-truck> From: Guenter Roeck Autocrypt: addr=linux@roeck-us.net; keydata= xsFNBE6H1WcBEACu6jIcw5kZ5dGeJ7E7B2uweQR/4FGxH10/H1O1+ApmcQ9i87XdZQiB9cpN RYHA7RCEK2dh6dDccykQk3bC90xXMPg+O3R+C/SkwcnUak1UZaeK/SwQbq/t0tkMzYDRxfJ7 nyFiKxUehbNF3r9qlJgPqONwX5vJy4/GvDHdddSCxV41P/ejsZ8PykxyJs98UWhF54tGRWFl 7i1xvaDB9lN5WTLRKSO7wICuLiSz5WZHXMkyF4d+/O5ll7yz/o/JxK5vO/sduYDIlFTvBZDh gzaEtNf5tQjsjG4io8E0Yq0ViobLkS2RTNZT8ICq/Jmvl0SpbHRvYwa2DhNsK0YjHFQBB0FX IdhdUEzNefcNcYvqigJpdICoP2e4yJSyflHFO4dr0OrdnGLe1Zi/8Xo/2+M1dSSEt196rXaC kwu2KgIgmkRBb3cp2vIBBIIowU8W3qC1+w+RdMUrZxKGWJ3juwcgveJlzMpMZNyM1jobSXZ0 VHGMNJ3MwXlrEFPXaYJgibcg6brM6wGfX/LBvc/haWw4yO24lT5eitm4UBdIy9pKkKmHHh7s jfZJkB5fWKVdoCv/omy6UyH6ykLOPFugl+hVL2Prf8xrXuZe1CMS7ID9Lc8FaL1ROIN/W8Vk BIsJMaWOhks//7d92Uf3EArDlDShwR2+D+AMon8NULuLBHiEUQARAQABzTJHdWVudGVyIFJv ZWNrIChMaW51eCBhY2NvdW50KSA8bGludXhAcm9lY2stdXMubmV0PsLBgQQTAQIAKwIbAwYL CQgHAwIGFQgCCQoLBBYCAwECHgECF4ACGQEFAlVcphcFCRmg06EACgkQyx8mb86fmYFg0RAA nzXJzuPkLJaOmSIzPAqqnutACchT/meCOgMEpS5oLf6xn5ySZkl23OxuhpMZTVX+49c9pvBx hpvl5bCWFu5qC1jC2eWRYU+aZZE4sxMaAGeWenQJsiG9lP8wkfCJP3ockNu0ZXXAXwIbY1O1 c+l11zQkZw89zNgWgKobKzrDMBFOYtAh0pAInZ9TSn7oA4Ctejouo5wUugmk8MrDtUVXmEA9 7f9fgKYSwl/H7dfKKsS1bDOpyJlqhEAH94BHJdK/b1tzwJCFAXFhMlmlbYEk8kWjcxQgDWMu GAthQzSuAyhqyZwFcOlMCNbAcTSQawSo3B9yM9mHJne5RrAbVz4TWLnEaX8gA5xK3uCNCeyI sqYuzA4OzcMwnnTASvzsGZoYHTFP3DQwf2nzxD6yBGCfwNGIYfS0i8YN8XcBgEcDFMWpOQhT Pu3HeztMnF3HXrc0t7e5rDW9zCh3k2PA6D2NV4fews9KDFhLlTfCVzf0PS1dRVVWM+4jVl6l HRIAgWp+2/f8dx5vPc4Ycp4IsZN0l1h9uT7qm1KTwz+sSl1zOqKD/BpfGNZfLRRxrXthvvY8 BltcuZ4+PGFTcRkMytUbMDFMF9Cjd2W9dXD35PEtvj8wnEyzIos8bbgtLrGTv/SYhmPpahJA l8hPhYvmAvpOmusUUyB30StsHIU2LLccUPPOwU0ETofVZwEQALlLbQeBDTDbwQYrj0gbx3bq 7kpKABxN2MqeuqGr02DpS9883d/t7ontxasXoEz2GTioevvRmllJlPQERVxM8gQoNg22twF7 pB/zsrIjxkE9heE4wYfN1AyzT+AxgYN6f8hVQ7Nrc9XgZZe+8IkuW/Nf64KzNJXnSH4u6nJM J2+Dt274YoFcXR1nG76Q259mKwzbCukKbd6piL+VsT/qBrLhZe9Ivbjq5WMdkQKnP7gYKCAi pNVJC4enWfivZsYupMd9qn7Uv/oCZDYoBTdMSBUblaLMwlcjnPpOYK5rfHvC4opxl+P/Vzyz 6WC2TLkPtKvYvXmdsI6rnEI4Uucg0Au/Ulg7aqqKhzGPIbVaL+U0Wk82nz6hz+WP2ggTrY1w ZlPlRt8WM9w6WfLf2j+PuGklj37m+KvaOEfLsF1v464dSpy1tQVHhhp8LFTxh/6RWkRIR2uF I4v3Xu/k5D0LhaZHpQ4C+xKsQxpTGuYh2tnRaRL14YMW1dlI3HfeB2gj7Yc8XdHh9vkpPyuT nY/ZsFbnvBtiw7GchKKri2gDhRb2QNNDyBnQn5mRFw7CyuFclAksOdV/sdpQnYlYcRQWOUGY HhQ5eqTRZjm9z+qQe/T0HQpmiPTqQcIaG/edgKVTUjITfA7AJMKLQHgp04Vylb+G6jocnQQX JqvvP09whbqrABEBAAHCwWUEGAECAA8CGwwFAlVcpi8FCRmg08MACgkQyx8mb86fmYHNRQ/+ J0OZsBYP4leJvQF8lx9zif+v4ZY/6C9tTcUv/KNAE5leyrD4IKbnV4PnbrVhjq861it/zRQW cFpWQszZyWRwNPWUUz7ejmm9lAwPbr8xWT4qMSA43VKQ7ZCeTQJ4TC8kjqtcbw41SjkjrcTG wF52zFO4bOWyovVAPncvV9eGA/vtnd3xEZXQiSt91kBSqK28yjxAqK/c3G6i7IX2rg6pzgqh hiH3/1qM2M/LSuqAv0Rwrt/k+pZXE+B4Ud42hwmMr0TfhNxG+X7YKvjKC+SjPjqp0CaztQ0H nsDLSLElVROxCd9m8CAUuHplgmR3seYCOrT4jriMFBtKNPtj2EE4DNV4s7k0Zy+6iRQ8G8ng QjsSqYJx8iAR8JRB7Gm2rQOMv8lSRdjva++GT0VLXtHULdlzg8VjDnFZ3lfz5PWEOeIMk7Rj trjv82EZtrhLuLjHRCaG50OOm0hwPSk1J64R8O3HjSLdertmw7eyAYOo4RuWJguYMg5DRnBk WkRwrSuCn7UG+qVWZeKEsFKFOkynOs3pVbcbq1pxbhk3TRWCGRU5JolI4ohy/7JV1TVbjiDI HP/aVnm6NC8of26P40Pg8EdAhajZnHHjA7FrJXsy3cyIGqvg9os4rNkUWmrCfLLsZDHD8FnU mDW4+i+XlNFUPUYMrIKi9joBhu18ssf5i5Q= Message-ID: Date: Tue, 26 May 2020 09:18:54 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <20200526140126.GD27166@willie-the-truck> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/26/20 7:01 AM, Will Deacon wrote: > On Tue, May 26, 2020 at 02:26:35PM +0100, Will Deacon wrote: >> On Sun, May 24, 2020 at 03:32:56PM +0300, Mike Rapoport wrote: >>> On Thu, May 21, 2020 at 04:02:11PM -0700, Guenter Roeck wrote: >>>> On 5/20/20 12:51 PM, Mike Rapoport wrote: >>>>> On Wed, May 20, 2020 at 12:03:31PM -0700, Guenter Roeck wrote: >>>>>> With above patch applied on top of Ira's patch, I get: >>>>>> >>>>>> BUG: spinlock recursion on CPU#0, S01syslogd/139 >>>>>> lock: 0xf5448350, .magic: dead4ead, .owner: S01syslogd/139, .owner_cpu: 0 >>>>>> CPU: 0 PID: 139 Comm: S01syslogd Not tainted 5.7.0-rc6-next-20200518-00002-gb178d2d56f29-dirty #1 >>>>>> [f0067a64 : >>>>>> do_raw_spin_lock+0xa8/0xd8 ] >>>>>> [f00d5034 : >>>>>> copy_page_range+0x328/0x804 ] >>>>>> [f0025be4 : >>>>>> dup_mm+0x334/0x434 ] >>>>>> [f0027124 : >>>>>> copy_process+0x1224/0x12b0 ] >>>>>> [f0027344 : >>>>>> _do_fork+0x54/0x30c ] >>>>>> [f0027670 : >>>>>> do_fork+0x5c/0x6c ] >>>>>> [f000de44 : >>>>>> sparc_do_fork+0x18/0x38 ] >>>>>> [f000b7f4 : >>>>>> do_syscall+0x34/0x40 ] >>>>>> [5010cd4c : >>>>>> 0x5010cd4c ] >>>>>> >>>>>> Looks like yet another problem. >>>>> >>>>> I've checked the patch above on top of the mmots which already has Ira's >>>>> patches and it booted fine. I've used sparc32_defconfig to build the >>>>> kernel and qemu-system-sparc with default machine and CPU. >>>>> >>>> >>>> Try sparc32_defconfig+SMP. >>> >>> I see a differernt problem, but this could be related: >>> >>> INIT: version 2.86 booting >>> rcu: INFO: rcu_sched detected stalls on CPUs/tasks: >>> (detected by 0, t=5252 jiffies, g=-935, q=3) >>> rcu: All QSes seen, last rcu_sched kthread activity 5252 (-68674--73926), jiffies_till_next_fqs=1, root ->qsmask 0x0 >>> rcu: rcu_sched kthread starved for 5252 jiffies! g-935 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 >>> rcu: Unless rcu_sched kthread gets sufficient CPU time, OOM is now expected behavior. >>> rcu: RCU grace-period kthread stack dump: >>> rcu_sched R running task 0 10 2 0x00000000 >>> >>> I'm running a bit old debian [1] with qemu-img-sparc. >>> >>> My bisect pointed at commit 8c8f3156dd40 ("sparc32: mm: Reduce >>> allocation size for PMD and PTE tables"). The commit ID is valid for >>> next-20200522. >> >> Can you try the diff below please? > > Actually, that's racy. New version below! > Applied on top of next-20200526, with defconfig+SMP, I still get: BUG: Bad page state in process swapper/0 pfn:0069f many times. Did I have to revert something else ? Sorry, I lost track. Note that "-smp 2" on SS-10 works for me (with the same page state messages). Guenter > Will > > --->8 > > diff --git a/arch/sparc/mm/srmmu.c b/arch/sparc/mm/srmmu.c > index c861c0f0df73..068029471aa4 100644 > --- a/arch/sparc/mm/srmmu.c > +++ b/arch/sparc/mm/srmmu.c > @@ -363,11 +363,16 @@ pgtable_t pte_alloc_one(struct mm_struct *mm) > > if ((ptep = pte_alloc_one_kernel(mm)) == 0) > return NULL; > + > page = pfn_to_page(__nocache_pa((unsigned long)ptep) >> PAGE_SHIFT); > - if (!pgtable_pte_page_ctor(page)) { > - __free_page(page); > - return NULL; > + > + spin_lock(&mm->page_table_lock); > + if (page_ref_inc_return(page) == 2 && !pgtable_pte_page_ctor(page)) { > + page_ref_dec(page); > + ptep = NULL; > } > + spin_unlock(&mm->page_table_lock); > + > return ptep; > } > > @@ -376,7 +381,12 @@ void pte_free(struct mm_struct *mm, pgtable_t ptep) > struct page *page; > > page = pfn_to_page(__nocache_pa((unsigned long)ptep) >> PAGE_SHIFT); > - pgtable_pte_page_dtor(page); > + > + spin_lock(&mm->page_table_lock); > + if (page_ref_dec_return(page) == 1) > + pgtable_pte_page_dtor(page); > + spin_unlock(&mm->page_table_lock); > + > srmmu_free_nocache(ptep, SRMMU_PTE_TABLE_SIZE); > } > > diff --git a/mm/Kconfig b/mm/Kconfig > index c1acc34c1c35..97458119cce8 100644 > --- a/mm/Kconfig > +++ b/mm/Kconfig > @@ -192,6 +192,9 @@ config MEMORY_HOTREMOVE > # Default to 4 for wider testing, though 8 might be more appropriate. > # ARM's adjust_pte (unused if VIPT) depends on mm-wide page_table_lock. > # PA-RISC 7xxx's spinlock_t would enlarge struct page from 32 to 44 bytes. > +# SPARC32 allocates multiple pte tables within a single page, and therefore > +# a per-page lock leads to problems when multiple tables need to be locked > +# at the same time (e.g. copy_page_range()). > # DEBUG_SPINLOCK and DEBUG_LOCK_ALLOC spinlock_t also enlarge struct page. > # > config SPLIT_PTLOCK_CPUS > @@ -199,6 +202,7 @@ config SPLIT_PTLOCK_CPUS > default "999999" if !MMU > default "999999" if ARM && !CPU_CACHE_VIPT > default "999999" if PARISC && !PA20 > + default "999999" if SPARC32 > default "4" > > config ARCH_ENABLE_SPLIT_PMD_PTLOCK >