On Thu, 7 Jun 2007, Eric Dumazet wrote: > Davide, are you sure we want FIFO for non sequential allocations ? > > This tends to use all the fmap slots, and not very cache friendly > if an app does a lot of [open(),...,close()] things. We already got a > perf drop because of RCUification of file freeing (FIFO mode instead > of LIFO given by kmalloc()/kfree()) > > If the idea behind this FIFO was security (ie not easy for an app to predict > next glibc file handle), we/glibc might use yet another FD_SECUREMODE flag, > wich ORed with O_NONSEQFD would ask to fdmap_newfd() to take the tail of > fmap->slist, not head.
Uli, would it be OK to rely only on base randomization and use a LIFO instead? We have base randomization, plus LIFO does not mean strictly sequential like legacy allocator, just more compatc and cache friendly. - Davide - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
