On Wed 03-07-19 04:04:57, Boaz Harrosh wrote: > On 19/06/2019 11:21, Jan Kara wrote: > <> > > Yes, I have patch to make madvise(MADV_WILLNEED) go through ->fadvise() as > > well. I'll post it soon since the rest of the series isn't really dependent > > on it. > > > > Honza > > > > Hi Jan > > Funny I'm sitting on the same patch since LSF last. I need it too for other > reasons. I have not seen, have you pushed your patch yet? > (Is based on old v4.20) Your patch is wrong due to lock ordering. You should not call vfs_fadvise() under mmap_sem. So we need to do a similar dance like madvise_remove(). I have to get to writing at least XFS fix so that the madvise change gets used and post the madvise patch with it... Sorry it takes me so long. Honza > > ~~~~~~~~~ > From fddb38169e33d23060ddd444ba6f2319f76edc89 Mon Sep 17 00:00:00 2001 > From: Boaz Harrosh <boazh@xxxxxxxxxx> > Date: Thu, 16 May 2019 20:02:14 +0300 > Subject: [PATCH] mm: Support madvise_willneed override by Filesystems > > In the patchset: > [b833a3660394] ovl: add ovl_fadvise() > [3d8f7615319b] vfs: implement readahead(2) using POSIX_FADV_WILLNEED > [45cd0faae371] vfs: add the fadvise() file operation > > Amir Goldstein introduced a way for filesystems to overide fadvise. > Well madvise_willneed is exactly as fadvise_willneed except it always > returns 0. > > In this patch we call the FS vector if it exists. > > NOTE: I called vfs_fadvise(..,POSIX_FADV_WILLNEED); > (Which is my artistic preference) > > I could also selectively call > if (file->f_op->fadvise) > return file->f_op->fadvise(..., POSIX_FADV_WILLNEED); > If we fear theoretical side effects. I don't mind either way. > > CC: Amir Goldstein <amir73il@xxxxxxxxx> > CC: Miklos Szeredi <mszeredi@xxxxxxxxxx> > Signed-off-by: Boaz Harrosh <boazh@xxxxxxxxxx> > --- > mm/madvise.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/mm/madvise.c b/mm/madvise.c > index 6cb1ca93e290..6b84ddcaaaf2 100644 > --- a/mm/madvise.c > +++ b/mm/madvise.c > @@ -24,6 +24,7 @@ > #include <linux/swapops.h> > #include <linux/shmem_fs.h> > #include <linux/mmu_notifier.h> > +#include <linux/fadvise.h> > > #include <asm/tlb.h> > > @@ -303,7 +304,8 @@ static long madvise_willneed(struct vm_area_struct *vma, > end = vma->vm_end; > end = ((end - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; > > - force_page_cache_readahead(file->f_mapping, file, start, end - start); > + vfs_fadvise(file, start << PAGE_SHIFT, (end - start) << PAGE_SHIFT, > + POSIX_FADV_WILLNEED); > return 0; > } > > -- > 2.20.1 > -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
