Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756219AbbGFNrz (ORCPT ); Mon, 6 Jul 2015 09:47:55 -0400 Received: from mx1.redhat.com ([209.132.183.28]:49959 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756186AbbGFNrw (ORCPT ); Mon, 6 Jul 2015 09:47:52 -0400 Date: Mon, 6 Jul 2015 09:47:50 -0400 From: Mike Snitzer To: Mikulas Patocka Cc: "Alasdair G. Kergon" , Edward Thornber , dm-devel@redhat.com, David Rientjes , Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: [PATCH 4/7] dm: introduce dm_kvmalloc Message-ID: <20150706134750.GA31600@redhat.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5547 Lines: 148 On Fri, Jul 03 2015 at 4:59pm -0400, Mikulas Patocka wrote: > Introduce the functions dm_kvmalloc and dm_kvmalloc_node. These functions > attempt to do allocation with kmalloc and if it fails, use vmalloc. Memory > allocated with these functions should be freed with kvfree (that function > is already present in the Linux kernel). > > Signed-off-by: Mikulas Patocka > > --- > drivers/md/dm-ioctl.c | 26 +++++--------------------- > drivers/md/dm-table.c | 37 +++++++++++++++++++++++++++++++++++++ > include/linux/device-mapper.h | 2 ++ > 3 files changed, 44 insertions(+), 21 deletions(-) > > Index: linux-4.1/drivers/md/dm-ioctl.c > =================================================================== > --- linux-4.1.orig/drivers/md/dm-ioctl.c 2015-07-02 19:21:15.000000000 +0200 > +++ linux-4.1/drivers/md/dm-ioctl.c 2015-07-02 19:21:21.000000000 +0200 > @@ -1676,12 +1676,8 @@ static void free_params(struct dm_ioctl > if (param_flags & DM_WIPE_BUFFER) > memset(param, 0, param_size); > > - if (param_flags & DM_PARAMS_ALLOC) { > - if (is_vmalloc_addr(param)) > - vfree(param); > - else > - kfree(param); > - } > + if (param_flags & DM_PARAMS_ALLOC) > + kvfree(param); > } > > static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kernel, > @@ -1712,21 +1708,7 @@ static int copy_params(struct dm_ioctl _ > * Try to avoid low memory issues when a device is suspended. > * Use kmalloc() rather than vmalloc() when we can. > */ > - dmi = NULL; > - if (param_kernel->data_size <= KMALLOC_MAX_SIZE) { > - dmi = kmalloc(param_kernel->data_size, GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN); > - if (dmi) > - *param_flags |= DM_PARAMS_ALLOC; > - } > - > - if (!dmi) { > - unsigned noio_flag; > - noio_flag = memalloc_noio_save(); > - dmi = __vmalloc(param_kernel->data_size, GFP_NOIO | __GFP_REPEAT | __GFP_HIGH | __GFP_HIGHMEM, PAGE_KERNEL); > - memalloc_noio_restore(noio_flag); > - if (dmi) > - *param_flags |= DM_PARAMS_ALLOC; > - } > + dmi = dm_kvmalloc(param_kernel->data_size, GFP_NOIO); > > if (!dmi) { > if (secure_data && clear_user(user, param_kernel->data_size)) > @@ -1734,6 +1716,8 @@ static int copy_params(struct dm_ioctl _ > return -ENOMEM; > } > > + *param_flags |= DM_PARAMS_ALLOC; > + > if (copy_from_user(dmi, user, param_kernel->data_size)) > goto bad; > > Index: linux-4.1/include/linux/device-mapper.h > =================================================================== > --- linux-4.1.orig/include/linux/device-mapper.h 2015-07-02 19:21:16.000000000 +0200 > +++ linux-4.1/include/linux/device-mapper.h 2015-07-02 19:21:21.000000000 +0200 > @@ -475,6 +475,8 @@ struct dm_table *dm_swap_table(struct ma > /* > * A wrapper around vmalloc. > */ > +void *dm_kvmalloc_node(size_t size, gfp_t gfp, int node); > +void *dm_kvmalloc(size_t size, gfp_t gfp); > void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size); > > /*----------------------------------------------------------------- > Index: linux-4.1/drivers/md/dm-table.c > =================================================================== > --- linux-4.1.orig/drivers/md/dm-table.c 2015-07-02 19:21:16.000000000 +0200 > +++ linux-4.1/drivers/md/dm-table.c 2015-07-02 19:28:18.000000000 +0200 > @@ -131,6 +131,43 @@ static int setup_btree_index(unsigned in > return 0; > } > > +void *dm_kvmalloc_node(size_t size, gfp_t gfp, int node) > +{ > + void *p; > + unsigned uninitialized_var(noio_flag); > + > + /* vmalloc doesn't support no-wait allocations */ > + WARN_ON(!(gfp & __GFP_WAIT)); > + > + if (likely(size <= KMALLOC_MAX_SIZE)) { > + p = kmalloc_node(size, gfp | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN, node); > + if (likely(p != NULL)) > + return p; > + } > + if ((gfp & (__GFP_IO | __GFP_FS)) != (__GFP_IO | __GFP_FS)) { > + /* > + * vmalloc allocates page tables with GFP_KERNEL, regardless > + * of GFP flags passed to it. If we are no GFP_NOIO context, > + * we call memalloc_noio_save, so that all allocations are > + * implicitly done with GFP_NOIO. > + */ > + noio_flag = memalloc_noio_save(); > + gfp |= __GFP_HIGH; > + } > + p = __vmalloc_node_flags(size, node, gfp | __GFP_REPEAT | __GFP_HIGHMEM); > + if ((gfp & (__GFP_IO | __GFP_FS)) != (__GFP_IO | __GFP_FS)) { > + memalloc_noio_restore(noio_flag); > + } > + return p; > +} > +EXPORT_SYMBOL(dm_kvmalloc_node); > + > +void *dm_kvmalloc(size_t size, gfp_t gfp) > +{ > + return dm_kvmalloc_node(size, gfp, NUMA_NO_NODE); > +} > +EXPORT_SYMBOL(dm_kvmalloc); > + > void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size) > { > unsigned long size; > In general I like what you've done with this patchset _except_ I'm not seeing why dm_kvmalloc() should be in DM at all. It should probably be elevated to an kvmalloc() export from mm/util.c and include/linux/mm.h along-side kvfree(). David and/or Andrew, what do you think? FYI, full patchset starts here: https://www.redhat.com/archives/dm-devel/2015-July/msg00004.html (but Mikulas didn't chain the reply so the 7 patches aren't properly threaded/navigated, you can dig out the patches toward the top of the list here: https://patchwork.kernel.org/project/dm-devel/list/ ) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/