Messages in this thread | | | Subject | Re: [PATCH -mm] relayfs: support larger relay buffer | From | Tom Zanussi <> | Date | Tue, 15 Apr 2008 23:22:49 -0500 |
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On Tue, 2008-04-15 at 11:27 -0400, Masami Hiramatsu wrote: > Use vmalloc() and memset() instead of kcalloc() to allocate a page* array > when the array size is bigger than one page. This enables relayfs to support > bigger relay buffers than 64MB on 4k-page system, 512MB on 16k-page system. > > Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> > --- > This is useful for a 64-bit system which has a plenty of memory (tens of > giga bytes) and a large kernel memory space. > > I tested it on x86-64 and ia64. >
Hi,
It looks ok to me, but it might be a little cleaner and avoid some duplication if you add the new code as a couple of functions instead. Just a suggestion...
Tom
> kernel/relay.c | 22 ++++++++++++++++++---- > 1 file changed, 18 insertions(+), 4 deletions(-) > > Index: 2.6.25-rc8-mm2/kernel/relay.c > =================================================================== > --- 2.6.25-rc8-mm2.orig/kernel/relay.c > +++ 2.6.25-rc8-mm2/kernel/relay.c > @@ -104,12 +104,20 @@ static int relay_mmap_buf(struct rchan_b > static void *relay_alloc_buf(struct rchan_buf *buf, size_t *size) > { > void *mem; > - unsigned int i, j, n_pages; > + unsigned int i, j, n_pages, pa_size; > > *size = PAGE_ALIGN(*size); > n_pages = *size >> PAGE_SHIFT; > + pa_size = n_pages * sizeof(struct page *); > > - buf->page_array = kcalloc(n_pages, sizeof(struct page *), GFP_KERNEL); > + if (pa_size > PAGE_SIZE) { > + buf->page_array = vmalloc(pa_size); > + if (buf->page_array) > + memset(buf->page_array, 0, pa_size); > + } else { > + buf->page_array = kcalloc(n_pages, sizeof(struct page *), > + GFP_KERNEL); > + } > if (!buf->page_array) > return NULL; > > @@ -130,7 +138,10 @@ static void *relay_alloc_buf(struct rcha > depopulate: > for (j = 0; j < i; j++) > __free_page(buf->page_array[j]); > - kfree(buf->page_array); > + if (pa_size > PAGE_SIZE) > + vfree(buf->page_array); > + else > + kfree(buf->page_array); > return NULL; > } > > @@ -189,7 +200,10 @@ static void relay_destroy_buf(struct rch > vunmap(buf->start); > for (i = 0; i < buf->page_count; i++) > __free_page(buf->page_array[i]); > - kfree(buf->page_array); > + if (buf->page_count * sizeof(struct page *) > PAGE_SIZE) > + vfree(buf->page_array); > + else > + kfree(buf->page_array); > } > chan->buf[buf->cpu] = NULL; > kfree(buf->padding);
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