On 07/03/2018 09:10 PM, Javier Gonzalez wrote:
On 2 Jul 2018, at 10.02, Matias Bjørling <mb@xxxxxxxxxxx> wrote: For devices that does not specify a limit on its transfer size, the get_chk_meta command may send down a single I/O retrieving the full chunk metadata table. Resulting in large 2-4MB I/O requests. Instead, split up the I/Os to a maximum of 256KB and issue them separately to reduce memory requirements. Signed-off-by: Matias Bjørling <mb@xxxxxxxxxxx> --- drivers/nvme/host/lightnvm.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/nvme/host/lightnvm.c b/drivers/nvme/host/lightnvm.c index b9989717418d..3b644b0e9713 100644 --- a/drivers/nvme/host/lightnvm.c +++ b/drivers/nvme/host/lightnvm.c @@ -583,7 +583,13 @@ static int nvme_nvm_get_chk_meta(struct nvm_dev *ndev, struct ppa_addr ppa; size_t left = nchks * sizeof(struct nvme_nvm_chk_meta); size_t log_pos, offset, len; - int ret, i; + int ret, i, max_len; + + /* + * limit requests to maximum 256K to avoid issuing arbitrary large + * requests when the device does not specific a maximum transfer size. + */ + max_len = min_t(unsigned int, ctrl->max_hw_sectors << 9, 256 * 1024); /* Normalize lba address space to obtain log offset */ ppa.ppa = slba; @@ -596,7 +602,7 @@ static int nvme_nvm_get_chk_meta(struct nvm_dev *ndev, offset = log_pos * sizeof(struct nvme_nvm_chk_meta); while (left) { - len = min_t(unsigned int, left, ctrl->max_hw_sectors << 9); + len = min_t(unsigned int, left, max_len); ret = nvme_get_log_ext(ctrl, ns, NVME_NVM_LOG_REPORT_CHUNK, dev_meta, len, offset); -- 2.11.0Is this a v2? I remember seeing this patch being posted before [1]. It still looks good to me :) [1] https://lkml.org/lkml/2018/6/12/466 Reviewed-by: Javier González <javier@xxxxxxxxxxxx>
I changed the title. Since it didn't touch pblk. Thanks.
