Message ID | 20180531033919.GA88973@redhat.com (mailing list archive) |
---|---|
State | Accepted, archived |
Delegated to: | Mike Snitzer |
Headers | show |
On Wed, 30 May 2018, Mike Snitzer wrote: > On Wed, May 30 2018 at 10:09P -0400, > Mikulas Patocka <mpatocka@redhat.com> wrote: > > > And what about this? > > #define WC_MODE_PMEM(wc) ((wc)->pmem_mode) > > > > The code that I had just allowed the compiler to optimize out > > persistent-memory code if we have DM_WRITECACHE_ONLY_SSD defined - and you > > deleted it. > > > > Most architectures don't have persistent memory and the dm-writecache > > driver could work in ssd-only mode on them. On these architectures, I > > define > > #define WC_MODE_PMEM(wc) false > > - and the compiler will just automatically remove the tests for that > > condition and the unused branch. It does also eliminate unused static > > functions. > > Here is the patch that I just folded into the rebased version of > dm-writecache now in the dm-4.18 branch. > > (I rebased ontop of Jens' latest block tree for 4.18 that now includes > the mempool_init changes, etc.) > > --- > drivers/md/dm-writecache.c | 17 +++++++++++++++-- > 1 file changed, 15 insertions(+), 2 deletions(-) > > diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c > index fcbfaf7c27ec..691b5ffb799f 100644 > --- a/drivers/md/dm-writecache.c > +++ b/drivers/md/dm-writecache.c > @@ -34,13 +34,21 @@ > #define BITMAP_GRANULARITY PAGE_SIZE > #endif > > +#if defined(CONFIG_ARCH_HAS_PMEM_API) && IS_ENABLED(CONFIG_DAX_DRIVER) > +#define DM_WRITECACHE_HAS_PMEM > +#endif > + > +#ifdef DM_WRITECACHE_HAS_PMEM > #define pmem_assign(dest, src) \ > do { \ > typeof(dest) uniq = (src); \ > memcpy_flushcache(&(dest), &uniq, sizeof(dest)); \ > } while (0) > +#else > +#define pmem_assign(dest, src) ((dest)) = (src)) > +#endif > > -#if defined(__HAVE_ARCH_MEMCPY_MCSAFE) && defined(CONFIG_ARCH_HAS_PMEM_API) > +#if defined(__HAVE_ARCH_MEMCPY_MCSAFE) && defined(DM_WRITECACHE_HAS_PMEM) > #define DM_WRITECACHE_HANDLE_HARDWARE_ERRORS > #endif > > @@ -87,8 +95,13 @@ struct wc_entry { > #endif > }; > > +#ifdef DM_WRITECACHE_HAS_PMEM > #define WC_MODE_PMEM(wc) ((wc)->pmem_mode) > #define WC_MODE_FUA(wc) ((wc)->writeback_fua) > +#else > +#define WC_MODE_PMEM(wc) false > +#define WC_MODE_FUA(wc) false > +#endif > #define WC_MODE_SORT_FREELIST(wc) (!WC_MODE_PMEM(wc)) > > struct dm_writecache { > @@ -1857,7 +1870,7 @@ static int writecache_ctr(struct dm_target *ti, unsigned argc, char **argv) > if (!strcasecmp(string, "s")) { > wc->pmem_mode = false; > } else if (!strcasecmp(string, "p")) { > -#if defined(CONFIG_ARCH_HAS_PMEM_API) && IS_ENABLED(CONFIG_DAX_DRIVER) > +#ifdef DM_WRITECACHE_HAS_PMEM > wc->pmem_mode = true; > wc->writeback_fua = true; > #else > -- > 2.15.0 OK. I think that persistent_memory_claim should also be conditioned based on DM_WRITECACHE_HAS_PMEM - i.e. if we have DM_WRITECACHE_HAS_PMEM, we don't need to use other ifdefs. Is there some difference between "#if IS_ENABLED(CONFIG_OPTION)" and "#if defined(CONFIG_OPTION)"? Mikulas -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel
diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c index fcbfaf7c27ec..691b5ffb799f 100644 --- a/drivers/md/dm-writecache.c +++ b/drivers/md/dm-writecache.c @@ -34,13 +34,21 @@ #define BITMAP_GRANULARITY PAGE_SIZE #endif +#if defined(CONFIG_ARCH_HAS_PMEM_API) && IS_ENABLED(CONFIG_DAX_DRIVER) +#define DM_WRITECACHE_HAS_PMEM +#endif + +#ifdef DM_WRITECACHE_HAS_PMEM #define pmem_assign(dest, src) \ do { \ typeof(dest) uniq = (src); \ memcpy_flushcache(&(dest), &uniq, sizeof(dest)); \ } while (0) +#else +#define pmem_assign(dest, src) ((dest)) = (src)) +#endif -#if defined(__HAVE_ARCH_MEMCPY_MCSAFE) && defined(CONFIG_ARCH_HAS_PMEM_API) +#if defined(__HAVE_ARCH_MEMCPY_MCSAFE) && defined(DM_WRITECACHE_HAS_PMEM) #define DM_WRITECACHE_HANDLE_HARDWARE_ERRORS #endif @@ -87,8 +95,13 @@ struct wc_entry { #endif }; +#ifdef DM_WRITECACHE_HAS_PMEM #define WC_MODE_PMEM(wc) ((wc)->pmem_mode) #define WC_MODE_FUA(wc) ((wc)->writeback_fua) +#else +#define WC_MODE_PMEM(wc) false +#define WC_MODE_FUA(wc) false +#endif #define WC_MODE_SORT_FREELIST(wc) (!WC_MODE_PMEM(wc)) struct dm_writecache { @@ -1857,7 +1870,7 @@ static int writecache_ctr(struct dm_target *ti, unsigned argc, char **argv) if (!strcasecmp(string, "s")) { wc->pmem_mode = false; } else if (!strcasecmp(string, "p")) { -#if defined(CONFIG_ARCH_HAS_PMEM_API) && IS_ENABLED(CONFIG_DAX_DRIVER) +#ifdef DM_WRITECACHE_HAS_PMEM wc->pmem_mode = true; wc->writeback_fua = true; #else