From: Marcin Nowakowski <marcin.nowakowski@imgtec.com> To: Serge Semin <fancer.lancer@gmail.com>, <ralf@linux-mips.org>, <paul.burton@imgtec.com>, <rabinv@axis.com>, <matt.redfearn@imgtec.com>, <james.hogan@imgtec.com>, <alexander.sverdlin@nokia.com>, <robh+dt@kernel.org>, <frowand.list@gmail.com> Cc: <Sergey.Semin@t-platforms.ru>, <linux-mips@linux-mips.org>, <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org> Subject: Re: [PATCH 10/21] MIPS memblock: Discard bootmem allocator initialization Date: Mon, 23 Jan 2017 08:55:27 +0100 [thread overview] Message-ID: <780ca27f-d582-4911-a1a6-bd5c8792c587@imgtec.com> (raw) In-Reply-To: <1482113266-13207-11-git-send-email-fancer.lancer@gmail.com> Hi Serge, On 19.12.2016 03:07, Serge Semin wrote: > Bootmem allocator initialization needs to be discarded. > PFN limit constants are still in use by some subsystems, so they > need to be properly initialized. The initialization is moved into > a separate method and performed with help of commonly used > platform-specific constants. It might me too simplified, but most > of the kernel platforms do it the same way. Moreover it's much > easier to debug it, when it's not that complicated. > > Signed-off-by: Serge Semin <fancer.lancer@gmail.com> > --- > arch/mips/kernel/setup.c | 193 ++++------------------------- > 1 file changed, 21 insertions(+), 172 deletions(-) > > diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c > index e746793..6562f55 100644 > --- a/arch/mips/kernel/setup.c > +++ b/arch/mips/kernel/setup.c > @@ -626,6 +626,25 @@ static void __init request_crashkernel(struct resource *res) { } > #endif /* !CONFIG_KEXEC */ > > /* > + * Calcualte PFN limits with respect to the defined memory layout > + */ > +static void __init find_pfn_limits(void) > +{ > + phys_addr_t ram_end = memblock_end_of_DRAM(); > + > + min_low_pfn = ARCH_PFN_OFFSET; > + max_low_pfn = PFN_UP(HIGHMEM_START); This doesn't look right - as this may set max_low_pfn to more than the actual physical memory size. In some cases this might be a serious problem and it doesn't look like any other platform does that. Even in MIPS code you can find uses of max_low_pfn that would be seriously affected by this change (vpe loader with CONFIG_MIPS_VPE_LOADER_TOM). > + max_pfn = PFN_UP(ram_end); > +#ifdef CONFIG_HIGHMEM > + highstart_pfn = max_low_pfn; > + highend_pfn = max_pfn <= highstart_pfn ? highstart_pfn : max_pfn; > +#endif > + pr_info("PFNs: low min %lu, low max %lu, high start %lu, high end %lu," > + "max %lu\n", > + min_low_pfn, max_low_pfn, highstart_pfn, highend_pfn, max_pfn); > +} > + > +/* > * Initialize the bootmem allocator. It also setup initrd related data > * if needed. > */ I fully agree with you that the current initialisation code is really complex and difficult to debug, but the modified one seems a bit too simplified. Regards, Marcin
WARNING: multiple messages have this Message-ID (diff)
From: Marcin Nowakowski <marcin.nowakowski@imgtec.com> To: Serge Semin <fancer.lancer@gmail.com>, ralf@linux-mips.org, paul.burton@imgtec.com, rabinv@axis.com, matt.redfearn@imgtec.com, james.hogan@imgtec.com, alexander.sverdlin@nokia.com, robh+dt@kernel.org, frowand.list@gmail.com Cc: Sergey.Semin@t-platforms.ru, linux-mips@linux-mips.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 10/21] MIPS memblock: Discard bootmem allocator initialization Date: Mon, 23 Jan 2017 08:55:27 +0100 [thread overview] Message-ID: <780ca27f-d582-4911-a1a6-bd5c8792c587@imgtec.com> (raw) Message-ID: <20170123075527.VQkCa61hYkLqfylWrlGQj-yMTKQbtoeSIUsLmwhyXBo@z> (raw) In-Reply-To: <1482113266-13207-11-git-send-email-fancer.lancer@gmail.com> Hi Serge, On 19.12.2016 03:07, Serge Semin wrote: > Bootmem allocator initialization needs to be discarded. > PFN limit constants are still in use by some subsystems, so they > need to be properly initialized. The initialization is moved into > a separate method and performed with help of commonly used > platform-specific constants. It might me too simplified, but most > of the kernel platforms do it the same way. Moreover it's much > easier to debug it, when it's not that complicated. > > Signed-off-by: Serge Semin <fancer.lancer@gmail.com> > --- > arch/mips/kernel/setup.c | 193 ++++------------------------- > 1 file changed, 21 insertions(+), 172 deletions(-) > > diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c > index e746793..6562f55 100644 > --- a/arch/mips/kernel/setup.c > +++ b/arch/mips/kernel/setup.c > @@ -626,6 +626,25 @@ static void __init request_crashkernel(struct resource *res) { } > #endif /* !CONFIG_KEXEC */ > > /* > + * Calcualte PFN limits with respect to the defined memory layout > + */ > +static void __init find_pfn_limits(void) > +{ > + phys_addr_t ram_end = memblock_end_of_DRAM(); > + > + min_low_pfn = ARCH_PFN_OFFSET; > + max_low_pfn = PFN_UP(HIGHMEM_START); This doesn't look right - as this may set max_low_pfn to more than the actual physical memory size. In some cases this might be a serious problem and it doesn't look like any other platform does that. Even in MIPS code you can find uses of max_low_pfn that would be seriously affected by this change (vpe loader with CONFIG_MIPS_VPE_LOADER_TOM). > + max_pfn = PFN_UP(ram_end); > +#ifdef CONFIG_HIGHMEM > + highstart_pfn = max_low_pfn; > + highend_pfn = max_pfn <= highstart_pfn ? highstart_pfn : max_pfn; > +#endif > + pr_info("PFNs: low min %lu, low max %lu, high start %lu, high end %lu," > + "max %lu\n", > + min_low_pfn, max_low_pfn, highstart_pfn, highend_pfn, max_pfn); > +} > + > +/* > * Initialize the bootmem allocator. It also setup initrd related data > * if needed. > */ I fully agree with you that the current initialisation code is really complex and difficult to debug, but the modified one seems a bit too simplified. Regards, Marcin
next prev parent reply other threads:[~2017-01-23 7:56 UTC|newest] Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-12-19 2:07 [PATCH 00/21] MIPS memblock: Remove bootmem code and switch to NO_BOOTMEM Serge Semin 2016-12-19 2:07 ` [PATCH 01/21] MIPS memblock: Unpin dts memblock sanity check method Serge Semin 2016-12-19 4:21 ` kbuild test robot 2016-12-19 4:21 ` kbuild test robot 2016-12-19 4:28 ` kbuild test robot 2016-12-19 4:28 ` kbuild test robot 2016-12-22 20:57 ` Rob Herring 2016-12-22 21:57 ` Serge Semin 2016-12-19 2:07 ` [PATCH 02/21] MIPS memblock: Add dts mem and reserved-mem callbacks Serge Semin 2016-12-19 4:13 ` kbuild test robot 2016-12-19 4:13 ` kbuild test robot 2016-12-19 2:07 ` [PATCH 03/21] MIPS memblock: Alter traditional add_memory_region() method Serge Semin 2016-12-19 2:07 ` [PATCH 04/21] MIPS memblock: Alter user-defined memory parameter parser Serge Semin 2017-01-23 7:55 ` Marcin Nowakowski 2017-01-23 7:55 ` Marcin Nowakowski 2016-12-19 2:07 ` [PATCH 05/21] MIPS memblock: Alter initrd memory reservation method Serge Semin 2016-12-19 5:08 ` kbuild test robot 2016-12-19 5:08 ` kbuild test robot 2016-12-19 2:07 ` [PATCH 06/21] MIPS memblock: Alter kexec-crashkernel parameters parser Serge Semin 2016-12-19 2:07 ` [PATCH 07/21] MIPS memblock: Alter elfcorehdr " Serge Semin 2016-12-19 4:09 ` kbuild test robot 2016-12-19 4:09 ` kbuild test robot 2016-12-19 2:07 ` [PATCH 08/21] MIPS memblock: Move kernel parameters parser into individual method Serge Semin 2016-12-19 2:07 ` [PATCH 09/21] MIPS memblock: Move kernel memory reservation to " Serge Semin 2016-12-19 2:07 ` [PATCH 10/21] MIPS memblock: Discard bootmem allocator initialization Serge Semin 2016-12-19 4:28 ` kbuild test robot 2016-12-19 4:28 ` kbuild test robot 2017-01-23 7:55 ` Marcin Nowakowski [this message] 2017-01-23 7:55 ` Marcin Nowakowski 2016-12-19 2:07 ` [PATCH 11/21] MIPS memblock: Add memblock sanity check method Serge Semin 2016-12-19 2:07 ` [PATCH 12/21] MIPS memblock: Add memblock print outs in debug Serge Semin 2016-12-19 2:07 ` [PATCH 13/21] MIPS memblock: Add memblock allocator initialization Serge Semin 2016-12-19 2:07 ` [PATCH 14/21] MIPS memblock: Alter IO resources initialization method Serge Semin 2016-12-19 2:07 ` [PATCH 15/21] MIPS memblock: Alter weakened MAAR " Serge Semin 2016-12-19 2:07 ` [PATCH 16/21] MIPS memblock: Alter paging " Serge Semin 2016-12-19 2:07 ` [PATCH 17/21] MIPS memblock: Alter high memory freeing method Serge Semin 2016-12-19 2:07 ` [PATCH 18/21] MIPS memblock: Slightly improve buddy allocator init method Serge Semin 2016-12-19 2:07 ` [PATCH 19/21] MIPS memblock: Add print out method of kernel virtual memory layout Serge Semin 2016-12-19 12:04 ` Matt Redfearn 2016-12-19 12:04 ` Matt Redfearn 2016-12-19 12:09 ` Serge Semin 2016-12-19 13:02 ` James Hogan 2016-12-19 13:02 ` James Hogan 2016-12-19 13:15 ` Serge Semin 2016-12-19 2:07 ` [PATCH 20/21] MIPS memblock: Add free low memory test method call Serge Semin 2016-12-19 2:07 ` [PATCH 21/21] MIPS memblock: Deactivate old bootmem allocator Serge Semin 2017-01-23 7:55 ` [PATCH 00/21] MIPS memblock: Remove bootmem code and switch to NO_BOOTMEM Marcin Nowakowski 2017-01-23 7:55 ` Marcin Nowakowski 2017-03-02 3:06 ` Florian Fainelli 2017-01-23 14:51 ` Joshua Kinard 2017-05-22 9:48 ` Marcin Nowakowski 2017-05-22 9:48 ` Marcin Nowakowski 2017-05-22 10:26 ` Serge Semin 2017-05-22 12:19 ` Marcin Nowakowski 2017-05-22 12:19 ` Marcin Nowakowski 2017-05-22 12:47 ` Joshua Kinard 2017-05-22 13:03 ` Serge Semin 2017-05-22 13:20 ` Alexander Sverdlin 2017-05-22 13:20 ` Alexander Sverdlin 2017-05-22 13:29 ` Serge Semin
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