From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 21 Aug 2007 16:26:20 -0500 From: Matt Mackall Subject: Re: [RFC][PATCH 4/9] pagemap: remove open-coded sizeof(unsigned long) Message-ID: <20070821212620.GJ30556@waste.org> References: <20070821204248.0F506A29@kernel> <20070821204251.67EF9E06@kernel> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070821204251.67EF9E06@kernel> Sender: owner-linux-mm@kvack.org Return-Path: To: Dave Hansen Cc: linux-mm@kvack.org List-ID: On Tue, Aug 21, 2007 at 01:42:51PM -0700, Dave Hansen wrote: > > I think the code gets easier to read when we give symbolic names > to some of the operations we're performing. I was sure we needed > this when I saw the header being built like this: > > ... > buf[2] = sizeof(unsigned long) > buf[3] = sizeof(unsigned long) > > I really couldn't remember what either field did ;( > > Signed-off-by: Dave Hansen Comment still rendered obsolete by previous patch. Otherwise: Acked-by: Matt Mackall > --- > > lxc-dave/fs/proc/task_mmu.c | 12 +++++++----- > 1 file changed, 7 insertions(+), 5 deletions(-) > > diff -puN fs/proc/task_mmu.c~pagemap-use-ENTRY_SIZE fs/proc/task_mmu.c > --- lxc/fs/proc/task_mmu.c~pagemap-use-ENTRY_SIZE 2007-08-21 13:30:51.000000000 -0700 > +++ lxc-dave/fs/proc/task_mmu.c 2007-08-21 13:30:51.000000000 -0700 > @@ -508,14 +508,16 @@ struct pagemapread { > unsigned long __user *out; > }; > > +#define PM_ENTRY_BYTES sizeof(unsigned long) > + > static int add_to_pagemap(unsigned long addr, unsigned long pfn, > struct pagemapread *pm) > { > __put_user(pfn, pm->out); > pm->out++; > - pm->pos += sizeof(unsigned long); > - pm->count -= sizeof(unsigned long); > pm->next = addr + PAGE_SIZE; > + pm->pos += PM_ENTRY_BYTES; > + pm->count -= PM_ENTRY_BYTES; > return 0; > } > > @@ -601,13 +603,13 @@ static ssize_t pagemap_read(struct file > goto out; > > ret = -EIO; > - svpfn = src / sizeof(unsigned long); > + svpfn = src / PM_ENTRY_BYTES; > addr = PAGE_SIZE * svpfn; > - if (svpfn * sizeof(unsigned long) != src) > + if (svpfn * PM_ENTRY_BYTES != src) > goto out; > evpfn = min((src + count) / sizeof(unsigned long) - 1, > ((~0UL) >> PAGE_SHIFT) + 1); > - count = (evpfn - svpfn) * sizeof(unsigned long); > + count = (evpfn - svpfn) * PM_ENTRY_BYTES; > end = PAGE_SIZE * evpfn; > //printk("src %ld svpfn %d evpfn %d count %d\n", src, svpfn, evpfn, count); > > _ -- Mathematics is the supreme nostalgia of our time. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org