On Mon, Nov 10, 2025 at 07:50:17PM +0530, Garg, Shivank wrote: > > > On 11/10/2025 7:22 PM, Lorenzo Stoakes wrote: > > On Mon, Nov 10, 2025 at 01:47:10PM +0000, Matthew Wilcox wrote: > >> On Mon, Nov 10, 2025 at 11:32:53AM +0000, Shivank Garg wrote: > >>> When MADV_COLLAPSE is called on file-backed mappings (e.g., executable > >>> text sections), the pages may still be dirty from recent writes. The > >> > >> That explanation derails my brain entirely. Text isn't writable! How > >> can the pages be dirty and file-backed text? > > > > Because they just compiled it and it's not been written back to disk yet :) > > Hi, > > It's not about compilation. My binaries are already compiled. > > The issue is copying those binary to a freshly mounted filesystem. > The page cache folios remain dirty until background writeback completes. > > Reproduces 100% for me: fresh XFS/EXT4 mount -> copy binary -> execute -> > MADV_COLLAPSE fails. > > Detail logs: > https://lore.kernel.org/all/[email protected]
It amounts to the same thing unless I'm missing something? You've done something to write out the file and then immediately execute before writeback completes. > > Thanks, > Shivank Thanks, Lorenzo
