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From: Dave Hansen <haveblue@us.ibm.com>
To: Bernhard Walle <bwalle@suse.de>
Cc: linux-kernel@vger.kernel.org, kexec@lists.infradead.org,
	akpm@linux-foundation.org, ak@suse.de
Subject: Re: [patch 2/3] Introduce BOOTMEM_EXCLUSIVE
Date: Tue, 16 Oct 2007 11:08:16 -0700	[thread overview]
Message-ID: <1192558097.17464.15.camel@localhost> (raw)
In-Reply-To: <20071016162858.545617122@strauss.suse.de>

On Tue, 2007-10-16 at 18:28 +0200, Bernhard Walle wrote:
> 
> @@ -736,7 +736,7 @@ static int __init smp_scan_config (unsig
>                         smp_found_config = 1;
>                         printk(KERN_INFO "found SMP MP-table at %08lx\n",
>                                                 virt_to_phys(mpf));
> -                       reserve_bootmem(virt_to_phys(mpf), PAGE_SIZE);
> +                       reserve_bootmem(virt_to_phys(mpf), PAGE_SIZE, 0);
>                         if (mpf->mpf_physptr) {
>                                 /* 

Could you give all of these 0's a name?  I really hate seeing random
magic numbers in these things.  0 completely kills the ability of
someone to read the code and figure out what it is trying to do without
going and looking at reserve_bootmem().

Or, alternatively, do something like this:

-extern void reserve_bootmem(unsigned long addr, unsigned long size);
+/*
+ * If flags is 0, then the return value is always 0 (success). If
+ * flags contains BOOTMEM_EXCLUSIVE, then -EBUSY is returned if the
+ * memory already was reserved.
+ */
+extern int reserve_bootmem(unsigned long addr, unsigned long size, int flag);
+int reserve_bootmem(unsigned long addr, unsigned long size)
+{
+	/* the 0 is because we don't
+	return reserve_bootmem_exclusive(addr, size, 0);
+}

Where all of the existing callers stay the same.  But, the ones wanting
exclusive access actually call the _exclusive() variant.  

-- Dave


  reply	other threads:[~2007-10-16 18:08 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-10-16 16:28 [patch 0/3] Protect crashkernel against BSS overlap Bernhard Walle
2007-10-16 16:28 ` [patch 1/3] Add BSS to resource tree Bernhard Walle
2007-10-16 16:28 ` [patch 2/3] Introduce BOOTMEM_EXCLUSIVE Bernhard Walle
2007-10-16 18:08   ` Dave Hansen [this message]
2007-10-16 18:44     ` Bernhard Walle
2007-10-16 18:58       ` Dave Hansen
2007-10-17 11:05   ` Vivek Goyal
2007-10-17 11:36     ` Bernhard Walle
2007-10-18  4:32       ` Vivek Goyal
2007-10-18 11:15     ` Bernhard Walle
2007-10-16 16:29 ` [patch 3/3] Use BOOTMEM_EXCLUSIVE on x86 Bernhard Walle
  -- strict thread matches above, loose matches on Subject: below --
2007-10-18 11:15 [patch 0/3] Protect crashkernel against BSS overlap Bernhard Walle
2007-10-18 11:15 ` [patch 2/3] Introduce BOOTMEM_EXCLUSIVE Bernhard Walle

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