As Christoph said [1], "vm_map_ram is supposed to generally behave better. So if it doesn't please report that that to the arch maintainer and linux-mm so that they can look into the issue. Having user make choices of deep down kernel internals is just a horrible interface. Please talk to maintainers of other bits of the kernel if you see issues and / or need enhancements. " Let's redo the previous conclusion and kill the vmap approach. [1] https://lore.kernel.org/r/20190830165533.GA10909@xxxxxxxxxxxxx/ Reported-by: Christoph Hellwig <hch@xxxxxxxxxxxxx> Signed-off-by: Gao Xiang <gaoxiang25@xxxxxxxxxx> --- Documentation/filesystems/erofs.txt | 4 --- fs/erofs/decompressor.c | 46 ++++++++--------------------- 2 files changed, 13 insertions(+), 37 deletions(-) diff --git a/Documentation/filesystems/erofs.txt b/Documentation/filesystems/erofs.txt index c3b5f603b2b6..b0c085326e2e 100644 --- a/Documentation/filesystems/erofs.txt +++ b/Documentation/filesystems/erofs.txt @@ -67,10 +67,6 @@ cache_strategy=%s Select a strategy for cached decompression from now on: It still does in-place I/O decompression for the rest compressed physical clusters. -Module parameters -================= -use_vmap=[0|1] Use vmap() instead of vm_map_ram() (default 0). - On-disk details =============== diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c index 8ed38504a9f1..37177d49d125 100644 --- a/fs/erofs/decompressor.c +++ b/fs/erofs/decompressor.c @@ -28,10 +28,6 @@ struct z_erofs_decompressor { char *name; }; -static bool use_vmap; -module_param(use_vmap, bool, 0444); -MODULE_PARM_DESC(use_vmap, "Use vmap() instead of vm_map_ram() (default 0)"); - static int z_erofs_lz4_prepare_destpages(struct z_erofs_decompress_req *rq, struct list_head *pagepool) { @@ -221,32 +217,6 @@ static void copy_from_pcpubuf(struct page **out, const char *dst, } } -static void *erofs_vmap(struct page **pages, unsigned int count) -{ - int i = 0; - - if (use_vmap) - return vmap(pages, count, VM_MAP, PAGE_KERNEL); - - while (1) { - void *addr = vm_map_ram(pages, count, -1, PAGE_KERNEL); - - /* retry two more times (totally 3 times) */ - if (addr || ++i >= 3) - return addr; - vm_unmap_aliases(); - } - return NULL; -} - -static void erofs_vunmap(const void *mem, unsigned int count) -{ - if (!use_vmap) - vm_unmap_ram(mem, count); - else - vunmap(mem); -} - static int z_erofs_decompress_generic(struct z_erofs_decompress_req *rq, struct list_head *pagepool) { @@ -255,7 +225,7 @@ static int z_erofs_decompress_generic(struct z_erofs_decompress_req *rq, const struct z_erofs_decompressor *alg = decompressors + rq->alg; unsigned int dst_maptype; void *dst; - int ret; + int ret, i; if (nrpages_out == 1 && !rq->inplace_io) { DBG_BUGON(!*rq->out); @@ -293,9 +263,19 @@ static int z_erofs_decompress_generic(struct z_erofs_decompress_req *rq, goto dstmap_out; } - dst = erofs_vmap(rq->out, nrpages_out); + i = 0; + while (1) { + dst = vm_map_ram(rq->out, nrpages_out, -1, PAGE_KERNEL); + + /* retry two more times (totally 3 times) */ + if (dst || ++i >= 3) + break; + vm_unmap_aliases(); + } + if (!dst) return -ENOMEM; + dst_maptype = 2; dstmap_out: @@ -304,7 +284,7 @@ static int z_erofs_decompress_generic(struct z_erofs_decompress_req *rq, if (!dst_maptype) kunmap_atomic(dst); else if (dst_maptype == 2) - erofs_vunmap(dst, nrpages_out); + vm_unmap_ram(dst, nrpages_out); return ret; } -- 2.17.1
