>>>>> "Boaz" == Boaz Harrosh <boaz@xxxxxxxxxxxxx> writes: Boaz> I do not know why I thought that only io_min does that, I can see Boaz> now that both effect the Kernel the same way. Which scares me a Boaz> bit. The difference is subtle. io_min is a hint from the storage about its preferred minimum I/O size. pbs describes the smallest unit that can be atomically written (like a sector on a drive with 512-byte logical/4K physical blocks). In most cases they are the same, pbs is just a slightly harder guarantee than io_min. What I was objecting to in your patch description was mostly the statement you made that these values affect kernel behavior. They really don't. Not directly, anyway. The queue limits are stacked and offsets are adjusted based on partitions, etc. But they don't alter the kernel runtime behavior. The queue limits are reported to userland and will affect things like partitioning, MD/DM tooling and mkfs.*. And therefore they only indirectly affect the kernel's behavior. -- Martin K. Petersen Oracle Linux Engineering -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
